Peer-reviewed Papers Published in Journals, Books, and Conference Proceedings
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In Press | 2013 | 2012 | 2011 | 2010 | 2009 | 2008 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 | 1999 | 1998 | 1997 | 1996 | 1995 | 1994
- Giacomin, David J. and David M. Levinson (2012)Road network circuity in metropolitan areas Circuity, the ratio of network to Euclidean distances, describes the directness of trips and the efficiency of transportation networks. This paper measures the circuity of the 51 most populated Metropolitan Statistical Areas (MSAs) in the United States and identifies trends in those circuities between 1990 and 2010. Overall circuity has increased between 1990 and 2010: random points have not only become farther apart in distance, their shortest network path has become more circuitous, suggesting that the more recently constructed parts of street networks are laid out more circuitously than older parts of the network. Over this period, 35 MSAs experienced a statistically significant increase in circuity (6 experienced a significant decrease). As expected, short trips are more circuitous than long trips. A new circuity distance decay function describes how circuity varies with distance within metropolitan areas. The parameters of this function have changed from 1990 to 2010. Presented at Transportation Research Board Annual Meeting, January 2014. Environment and Planning b (in press)
- Iacono, Michael and David Levinson (2013) Methods for Estimating the Economic Impacts of Transportation Improvements: An Interpretive Review Abstract: This chapter reviews several methods of evaluating the economic impacts of transportation improvements. We begin with a discussion of basic project-based methods, such as benefit- cost analysis, and discuss some issues which may complicate the accurate estimation of user benefits over the life of a project, especially the dynamic and recursive relationship between transportation networks and land development. We discuss the possible role of capitalized land value changes as an alternate source of estimated user benefits. We then move on to a discussion of regional economic analysis models as a tool for examining the effects of large- scale projects or packages of transportation improvements. Their linkages with non-traditional sources of benefits, such as agglomeration effects, and also network effects is considered. Lastly, we consider aggregate analysis methods. These include production function analy- ses, cliometric studies, and other types of empirical investigations of the relationship between transportation and econometric growth at an aggregate scale. We close by commenting on the merits of each approach, and where and how they might usefully be applied. An International Handbook on Transport and Development. Editors: Robin Hickman, David Bonilla, Moshe Givoni, David Banister. University of Oxford.
- Xin, Wuping and David Levinson (2006) Stochastic congestion and pricing model with endogenous departure time selection and heterogeneous travelers. This paper proposes a stochastic congestion and pricing model that combines a bottleneck model with stochastic queuing to study roadway congestion and pricing. Employing this model, two pricing schemes are developed: one is omniscient pricing for which the transportation administrative agency is assumed to be aware of each and every traveler's cost structure (i.e., their detailed valuation of journey cost as well as early and late penalties), and the other is observable pricing, for which only queuing delay is considered. Travelers are characterized by their late-acceptance level and the effects of various compositions of late-averse, late-tolerant and late-neutral travelers on congestion patterns with and without pricing are discussed. Numerical simulation indicates that omniscient pricing scheme is most effective in suppressing peak hour congestion and distributing demands over longer time horizon. Also, congestion pricing is found to be more effective when travelers have diversified cost structures than identical cost structures, and congestion is better reduced with heterogeneous traveler composition than with single composition. This is consistent with earlier studies in the literature. In addition, the simulation results indicate that omniscient pricing in general reduces Expected Total Social Cost (with or without the return of the congestion fee). However, the ultimate benefits of a certain pricing scheme depend on travelers' cost structure as well as the composition of late-tolerant, late-averse and late-neutral travelers in the entire population; extreme situations such as 100% late-averse or 100% late-tolerant traveler composition deserves extra attention when analyzing different pricing schemes. presented at 11th International Conference for Hong Kong Society of Transportation Studies, December 2006. Mathematical Population Studies (in press). [poster]
- Zhu, Shanjiang, David Levinson, and Henry Liu (2012)
Measuring Winners and Losers from the new I-35W Mississippi River Bridge.
The opening of the replacement for the I-35W Mississippi River Bridge bridge on September 18th, 2008 provides a unique opportunity to evaluate the impacts generated by this additional link on network performance, and thus empirically test whether a Braess Paradox occurred. Using detailed GPS data to estimate travel times on links and for origin-destination pairs, this research ﬁnds that while on average travel time improved with the reopening of the bridge, the subsequent restoration of parts of the rest of the network to their pre-collapse conﬁguration worsened travel times signiﬁcantly on average. In all cases, the distribution of winners and losers indicates clear spatial patterns associated with these network changes. While no Braess paradox was found in this case, the research provides a method for measuring such phenomena.
JEL code: R41, D81, D83
Keywords: Network structure, travel behavior, transport geography, commuting, network disruption, Braess paradox Presented at 89th Transportation Research Board Conference, January 2010, Washington , DC. Transportation (in press).
- Janson, M. and D. Levinson (2014) HOT or Not: Driver Elasticity to Price on the MnPASS HOT Lanes. The Minnesota Department of Transportation (MnDOT) has added MnPASS High Occupancy Toll (HOT) lanes on two freeway corridors. While not the first HOT lanes in the country, the MnPASS lanes are the first implementation of road pricing in Minnesota and possess a dynamic pricing schedule. Tolls charged to single occupancy vehicles (SOVs) are adjusted every three minutes according to HOT lane vehicle density. Given the infancy of systems like MnPASS, questions remain about drivers’ responses to toll prices. Three field experiments were conducted on the corridors during which prices were changed. Data from the field experiments as well as two years of toll and traffic data were analyzed to measure driver responses to pricing changes. Driver elasticity to price was positive with magnitudes less than 1.0. This positive relationship between price and demand is in contrast with the previously held belief that raising the price would discourage demand. We hypothesize this is because drivers use price as a signal of time savings. In addition, drivers consistently paid between approximately $60-120 per hour of travel time savings, much higher than the average value of time. Reasoning for these results is discussed as well as the implications these results have on the pricing of HOT lanes. Research in Transport Economics Volume 44 pp. 21-32 [doi]
- Owen, A., M. Janson and D. Levinson (2014) Incremental Accessibility Benefits and HOT Lane Subscription Choice. This paper presents the results of an investigation into the factors contributing to toll lane subscription choice using data from the MnPASS HOT lane system operated by the Minnesota Department of Transportation. A binomial logit model is estimated which predicts the likelihood that a household will have a subscription to the MnPASS system based on aggregate characteristics of the surrounding area. Variables in this model include demographic factors as well as an estimate of the incremental accessibility benefit provided by the MnPASS system. This benefit is estimated using detailed accessibility calculations. The model achieves a pseudo-r-squared value of 0.634, and analysis of the results suggest that incremental accessibility benefits play a statistically and practically significant role in determining how likely households are to hold a toll lane subscription. Transportation Research Record: Journal of the Transportation Research Board Volume 2412, pp. 93–99. [doi]
- Parthasarathi, Pavithra and David Levinson (2014)
Street Network Structure and Activity Spaces.
This research analyses the influence of street network structure on household travel patterns, as measured by activity spaces. The analysis uses street network and travel survey data from the Minneapolis – St. Paul (Twin Cities) and Miami – Ft. Lauderdale (South Florida) metropolitan areas. Various measures of street network structure are used to quantify street network structure. The activity space polygon for each household in the travel survey data set is identified by combining the destinations reached by all household members on the given travel day including the household location. Statistical regression models are then estimated for each study area to test the relationship between street network structure and household activity space. The results show that network structure has a significant influence on household travel patterns, after controlling for other non-network variables such as accessibility to jobs and shops, and car ownership.
JEL code: R41, R48, R53
Keywords: Transportation Geography, Network Structure, Circuity, Accessibility Urban Studies [doi] (online first)
- Schoner, J.E. and D. Levinson (2014) The Missing Link: Bicycle Infrastructure Networks and Ridership in 74 US Cities.
Abstract: Cities promote strong bicycle networks to support and encourage bicycle commuting. However, the application of network science to bicycle facilities is not very well studied. Previous work has found relationships between the amount of bicycle infrastructure in a city and aggregate bicycle ridership, and between microscopic network structure and individual tripmaking patterns. This study fills the missing link between these two bodies of literature by developing a standard methodology for measuring bicycle facility network quality at the macroscopic level and testing its association with bicycle commuting. Bicycle infrastructure maps were collected for 74 United States cities and systematically analyzed to evaluate their network structure. Linear regression models revealed that connectivity and directness are important factors in predicting bicycle commuting after controlling for demographic variables and the size of the city. These findings provide a framework for transportation planners and policymakers to evaluate their local bicycle facility networks and set regional priorities that support nonmotorized travel behavior, and for continued research on the structure and quality of bicycle infrastructure and behavior.
Keywords Bicycling · Travel Behavior · Networks Transportation Volume 41, Issue 6, pp 1187-1204 [doi]
- Anderson, Paul, David Levinson, and Pavithra Parthasarathi (2013) Accessibility Futures. This study uses accessibility as a performance measure to evaluate a matrix of future land use and network scenarios for planning purposes. The concept of accessibility dates to the 1950s, but this type of application to transportation planning is new. Previous research has established the coevolution of transportation and land use, demonstrated the dependence of accessibility on both, and made the case for the use of accessibility measures as a planning tool. This study builds off of these findings by demonstrating the use of accessibility-based performance measures on the Twin Cities Metropolitan Area. This choice of performance measure also allows for transit and highway networks to be compared side-by-side. For roadway modeling, zone-to-zone travel time matrix was computed using stochastic user equilibrium (SUE) assignment with travel time feedback to trip distribution. A database of schedules was used on the transit networks to assign transit routes. This travel time data was joined with the land use data from each scenario to obtain the employment, population, and labor accessibility from each traffic analysis zone (TAZ) within specified time ranges. Tables of person-weighted accessibility were computed for 20 minutes with zone population as the weight for employment accessibility and zone employment as the weight for population and labor accessibility. Maps of accessibility by zone were produced to show the spatial distribution of accessibility across the region. The results show that a scenario where population and employment growth are concentrated in the center of the metropolitan area would produce the highest accessibility no matter which transportation network changes are made. However, another scenario which concentrates population growth in the center of the metropolitan area and shifts employment growth to the periphery consistently outperforms the scenario representing the projected 2030 land use without any growth management strategy. Transactions in GIS 17(5) 683-705 [doi]
- Carrion, Carlos and Levinson, D. (2013),
Valuation of travel time reliability from a GPS-based experimental design
In the Minneapolis-St. Paul region (Twin Cities), the Minnesota Department of Transportation (Mn- DOT) converted the Interstate 394 High Occupancy Vehicle (HOV) lanes to High Occupancy Toll (HOT) lanes (or MnPASS Express Lanes). These lanes allow single occupancy vehicles (SOV) to access the HOV lanes by paying a fee. This fee is adjusted according to a dynamic pricing system that varies with the current demand. This paper estimates the value placed by the travelers on the HOT lanes because of improvements in travel time reliability. This value depends on how the travelers regard a route with predictable travel times (or small travel time variability) in comparison to another with unpredictable travel times (or high travel time variability). For this purpose, commuters are recruited and equipped with Global Positioning System (GPS) devices and instructed to commute for two weeks on each of three plausible alternatives between their home in the western suburbs of Minneapolis eastbound to work in downtown or the University of Minnesota: I-394 HOT lanes, I-394 General Purpose lanes (untolled), and signalized arterials close to the I-394 corridor. They are then given the opportunity to travel on their preferred route after experiencing each alternative. This revealed preference data is then analyzed using mixed logit route choice models. Three measures of reliability are explored and incorporated in the esti- mation of the models: standard deviation (a classical measure in the research literature); shortened right range (typically found in departure time choice models); and interquartile range (75th - 25th percentile). Each of these measures represents distinct ways about how travelers deal with different sections of reli- ability. In all the models, it was found that reliability was valued highly (and statistically significantly), but differently according to how it was defined. The estimated value of reliability in each of the models indicates that commuters are willing to pay a fee for a reliable route depending on how they value their reliability savings.
JEL-Code: R41, R48, D63
Keywords: time reliability, GPS, route choice, random utility, I-394 HOT, MnPass, mixed logit Transportation Research part C Volume 35, October 2013, Pages 305–323 [doi]
- Chi, Guangchi, Jeremy Porter, Arthur Cosby and David Levinson (2013) The impact of gasoline price changes on traffic safety: a time geography explanation. The impact of gasoline price changes on traffic safety has received increasing attention in empirical studies. In this study, we use time geography to provide a theoretical framework for examining the effects of time-varying fluctuations in gasoline prices and their relationship to traffic safety in a case study of Mississippi from April 2004 to December 2010. Application of time geography theory suggests that gasoline prices act as one type of capability constraint of the space–time path. As gasoline prices increase (that is, as the capability constraint becomes stronger), we hypothesize traffic crash rates decrease, and they decrease more for groups for whom the constraint is stronger. The results corroborate the hypotheses and suggest that gasoline prices have stronger effects on reducing less severe crashes and negligible effects on reducing fatal crashes. Gasoline price effects on reducing crashes start at a 9-month lag, peak at a 12-month lag, and diminish after an 18-month lag. Highlights: Gasoline prices are one type of capability constraint of space–time paths. As gasoline prices (capability constraint) increase, traffic safety improves. The impact is stronger on less severe crashes but negligible on fatal crashes. The impact starts at 9 months, peaks at 12 months, and diminishes after 18 months. Keywords: Time geography; Gasoline prices; Traffic safety; Traffic crashes; Fatal crashes; Space–time path Journal of Transport Geography Volume 28, April 2013, pp. 1-11 [doi]
- Chi, Guangchi, Mohammed Quddus, Arthur Huang and David Levinson (2013) Gasoline Price Effects on Traffic Safety in Urban and Rural Areas: Evidence from Minnesota, 1998–2007. A large literature base has found that economic factors have important effects on traffic crashes. A small but growing branch of literature also examines the role that gasoline prices play in the occurrence of traffic crashes. However, no studies have investigated the possible difference of these effects between urban and rural areas. In this study, we used the monthly traffic crash data from 1998–2007 at the county level in Minnesota to investigate the possibly different effects gasoline prices may have on traffic crashes in urban versus rural areas. The results indicate significant difference of gasoline price effects on total crashes in urban versus rural areas. Gasoline prices also significantly affect the frequency of injury crashes in both urban and rural areas; however, the difference is not significant. Gasoline prices have no significant effects on the frequency of fatal crashes in urban and rural areas. Traffic volume plays a bigger role on the incidence of injury and fatal crashes. The results concerning the differences between urban and rural areas have important policy implications for traffic safety planners and decision makers Safety Science 59: pp. 154-162 [ doi]
- Huang, Arthur and David Levinson (2013) The structure and evolution of a skyway network
We study the structure and evolution of the downtown Minneapolis, Minnesota skyway network. Developed by private building-owners, the network evolved from tree-like to grid-like over the course of 50 years. We find that decentralized forces with the goal of maximizing individual buildings' profitability shaped the network. Our analysis shows that a building with greater office size, a sign of greater accessibility, was more likely to be connected earlier. The distribution of existing skyway segments is found to follow a power-law function of the average degree, closeness, and eigenvector centralities of the vertices. We further explain and model the evolutionary process using an agent-based model. The simulation results suggest that the model replicates the network structure and its evolutionary process.
JEL code: R41, R48, Q41, R51
Keywords: skyway network, network growth, agent-based modeling The European Physical Journal: Special Topics January 2013, Volume 215, Issue 1, pp 123-134 [doi] [poster]
- Junge, Jason and David Levinson (2013)
Property Tax on Privatized Roads.
Roads cover a significant fraction of the land area in many municipalities. The public provision of roads means this land is exempt from the local property tax. Transferring roads from public to private ownership would not only remove maintenance costs from city budgets, but increase potential property tax revenue as well. This paper calculates the value of the land occupied by roads in sample cities and determines the potential revenue increase if they were subject to property tax. Further calculation computes the extent to which the property tax rate could be reduced if the land value of roads were added to the tax base.
JEL code: R40, R11, R14
Keywords: tax, land value, locational analysis, transportation finance Research in Transportation Business and Management. Volume 7. pp. 35-42. [doi]
- Levinson, David (2013) Commentary on "Infrastructure and Urban Development: Evidence from Chinese Cities" by Yan Song. Chapter 2 in Infrastructure and Land Policies: Proceedings of the 2012 Land Policy Conference. Editors Gregory K. Ingram and Karin L. Brandt. Lincoln Institute for Land Policy, Cambridge, Massachusetts.
- Liao, Chen-Fu and David Levinson (2013) ROAD: An Interactive Geometric Design Tool for Transportation Education and Training.
Traditionally, transportation engineering students use engineering drawing techniques to manually lay out lines and curves over contour maps for highway geometric design. The design process requires numerous calculations of stopping sight distance, minimum turning radius, and curve alignments, to minimize economic and environmental impact, and construction costs. Students usually perform iterative computations to manually meet design criteria and environmental constraints. The traditional approach of learning geometric design is cumbersome and time consuming, limiting students from taking a broader perspective on geometric design. A new tool, ROAD: Roadway Online Application for Design, was developed to enhance the learning experience for transportation engineering students. This tool allows students to design roadway geometry efficiently and modify the design easily within given economic and environmental parameters. The objective is to provide a comprehensive tool that can be accessed easily by students in order to help them better understand geometric design. ROAD can also generate a 3D roadway geometry model at final design to allow students to place themselves in the driver’s seat and maneuver through the designed roadway at maximum design speed. ROAD was introduced and deployed in a civil engineering undergraduate class in 2006 at the Department of Civil Engineering, University of Minnesota, and has been used there and at other schools since. The value of ROAD to student learning is evaluated and discussed in this paper. Survey results from students indicated that ROAD enhanced their learning experiences through performing geometric design.
Keywords: Roadway Geometry Design, Distance Learning, Transportation Visualization ASCE Journal of Professional Issues in Engineering Education and Practice 139(2), 116–122. [doi]
- Parthasarathi, Pavithra, David Levinson, and Hartwig Hochmair (2013) Network Structure and Travel Time Perception Road networks have an underlying structure. This structure is defined by the layout, arrangement and the connectivity of the individual network elements, the road segments and their intersections. The differences in network structure exist across and within networks. Travelers perceive and respond to these differences in underlying network structure and complexity. This paper extends the analysis to understanding the underlying theory of why network structure influences travel. Specifically the focus is on the influence of network structure on travel time perception. The hypothesis here is that network design influences traveler perceptions, more specifically the perceptions of travel distance and time. This perception of travel distance and time in turn influences the actual travel by affecting choice of destination, mode, route, and whether to engage in activities. (Presented at the 2012 International Association of Travel Behavior Research Conference in Toronto). PLOS One PLOS ONE: 8(10): e77718. [doi]
- Tilahun, Nebiyou and David Levinson (2013)
An Agent-Based Model of Worker and Job Matching.
This paper proposes and tests an agent-based model of worker and job matching. The model takes residential locations of workers and the locations of employers as exogenous and deals specifically with the interactions between firms and workers in creating a job-worker match and the commute outcomes. It is meant to illustrate that by explicitly modeling the search process and the interactions between firms and individuals, origins and destinations (ODs) can be linked at a disaggregate level that is reasonably true to the actual process. The model is tested on a toy-city and the using Twin Cities are. The toy-city model illustrated that the model leads to reasonable outcomes, with agents selecting the closest work place when wage and skill differentiation is absent. Relaxing these assumptions increases the observed commute. Especially the introduction of wage dispersion in the model increases the the average home to work distance significantly. Using data from Minnesota, the results on aggregate are shown to capture the trends in the observed data, and illustrate that the behavior rules as implemented lead to reasonable patterns. The results and potential future directions are also discussed.
JEL code: R41, R48, R53
Keywords: agent-based model, commuting, job search, residential location. Journal of Transport and Land Use 6(1) pp. 73-88 [doi].
- Tilahun, Nebiyou, and David Levinson (2013) Selfishness and Altruism in the Distribution of Travel Time and Income.
Most economic models assume that individuals act out their preferences based on self-interest alone. However, there have also been other paradigms in economics that aim to capture aspects of behavior that include fairness, reciprocity, and altruism. In this study we empirically examine preferences of travel time and income distributions with and without the respondent knowing their own position in each distribution. The data comes from a Stated Preference experiment where subjects were presented paired alternative distributions of travel time and income. The alternatives require a tradeoff between distributional concerns and the respondent’s own position. Choices also do not penalize or reward any particular choice. Overall, choices show individuals are willing forgo alternatives where they would be individually well off in the interest of distributional concerns in both the travel time and income cases. Exclusively self-interested choices are seen more in the income questions, where nearly 25 % of respondents express such preferences, than in the travel time case, where only 5 % of respondents make such choices. The results also suggest that respondents prioritize their own position differently relative to regional distributions of travel time and income. Estimated choice models show that when it comes to travel time, individuals are more concerned with societal average travel time followed by the standard deviation in the region and finally their own travel time, while in the case of income they are more concerned with their own income, followed by a desire for more variability, and finally increasing the minimum income in their region. When individuals do not know their fate after a policy change that affects regional travel time, their choices appear to be mainly motivated by risk averse behavior and aim to reduce variability in outcomes. On the other hand, in the income context, the expected value appears to drive choices. In all cases, population-wide tastes are also estimated and reported.
Keywords: selfishness, altruism, travel time distribution, income distribution, preferences, inequality, choice experiment. Transportation 40(5) pp 1043-1061 [presentation] [doi]
- Zhu, Shanjiang and David Levinson (2013), A Portfolio Theory of Route Choice
Although many individual route choice models have been proposed to incorporate travel time variability as a decision factor, they are typically still deterministic in the sense that the optimal strategy requires choosing one particular route that maximizes utility. In contrast, this study introduces an individual route choice model where choosing a portfolio of routes instead of a single route is the best strategy for a rational traveler who cares about both journey time and lateness when facing stochastic network conditions. The proposed model is compared with UE and SUE models and the difference in both behavioral foundation and model characteristics is highlighted. A numerical example is introduced to demonstrate how such model can be used in traffic assignment problem. The model is then tested with GPS data collected in metropolitan Minneapolis–St. Paul, Minnesota. Our data suggest there is no single dominant route (defined here as a route with the shortest travel time for a 15 day period) in 18% of cases when links travel times are correlated. This paper demonstrates that choosing a portfolio of routes could be the rational choice of a traveler who wants to optimize route decisions under variability.
JEL-Code: R41, R48, D63
Keywords: Transportation planning, route choice, travel behavior, link performance Transportation Research part C Volume 35, October 2013, Pages 232–243 [doi] [poster]
- Carrion, Carlos and David Levinson (2012)
Value of Travel Time Reliability: A review of current evidence.
Travel time reliability is a fundamental factor in travel behavior. It represents the temporal uncertainty experienced by users in their movement between any two nodes in a network. The importance of the time reliability depends on the penalties incurred by the users. In road networks, travelers consider the existence of a trip travel time uncertainty in different choice situations (departure time, route, mode, and others). In this paper, a systematic review of the current state of research in travel time reliability, and more explicitly in the value of travel time reliability is presented. Moreover, a meta-analysis is performed in order to determine the reasons behind the discrepancy among the reliability estimates.
JEL code: R41, R48, R53
Keywords: variability, reliability, travel time, scheduling. Transportation Research part A 46(4) 720--741. [doi]
- Fan, Yingling, Andrew Guthrie, and David Levinson (2012)
Impact of Light Rail Implementation on Labor Market Accessibility: A Transportation Equity Perspective.
This study examines transit's role in promoting social equity by assessing impacts of recent transit changes in the Twin Cities, including opening of the Hiawatha light rail line, on job accessibility among workers of different wage categories. Geo-spatial and descriptive analyses are employed to examine the magnitude of the accessibility changes and where changes occur. This study also uses regression analysis to estimate block-level before- and after-LRT accessibility as a function of the block's locational characteristics and demographic composition. The analysis finds that proximity to light rail stations and bus stops offering direct rail connections are associated with large, statistically significant gains in accessibility to low-wage jobs. These gains stand out from changes in accessibility for the transit system as a whole. The paper concludes by discussing implications of the study results for informing more equitable transit polices in the future.
JEL code: R41, R48, R53
Keywords: Transportation equity, transit, light rail, bus, Twin Cities, Minneapolis, St. Paul Journal of Transport and Land Use 5(3) pp.28-39 [doi]
- Huang, Arthur and Levinson, David (2012) To game or not to game: teaching transportation planning with board games. Traditional "chalk and talk" teaching in civil engineering has gradually been replaced with the idea of active learning focusing on encouraging students' knowledge discovery with innovative pedagogical methods and tools. One interesting tool is the board game. This research examines the efficacy of adopting transportation board games as a tool in graduate-level transportation planning and transportation economics classes at the Department of Civil Engineering of the University of Minnesota from 2008 to 2010. In these classes, a weekday night was scheduled for playing transportation board games. Students were asked to evaluate the effectiveness of the games on their learning and to write a self-reflective paper about their findings. The majority of the students reveal that their understanding of the planning process, network deployment, and practical issues, and and their ability to form opinion about transportation planning has been improved. Their summaries on the game economy and its implications on planning validate that their understanding obtained from this game process has met the pedagogical goals. Our analysis further shows that students who are moderately/highly visual, sensing, active, or sequential, all else equal, tend to learn more effectively through this approach than those who are not. Overall, this research suggests that properly incorporating board games into the curriculum can enhance students' learning process in transportation planning. Transportation Research Record: Journal of Transportation Research Board #2307 pp. 141–149. [doi] [Presentation]
- Huang, Arthur and David Levinson (2012)
STREET: Where simulation meets reality
Simulations and games are receiving increasing attention in teaching in higher education. In this context, we developed a series of simulation modules (STREET) in transportation engineering education and applied them in teaching undergraduate and graduate transportation courses at the University of Minnesota. After several years, we contend that they represent an effective pedagogical tool in transportation education. In this chapter we describe our motivation for this work, the program's development process, dissemination and impacts, and our future work.
Published in Cultivating Change in the Academy. Edited by Ann Hill Duin et al.
- Junge, Jason and David Levinson (2012)
Financing transportation with land value taxes: Effects on development intensity.
A significant portion of local transportation funding comes from the property
tax. The tax is conventionally assessed on both land and buildings, but transportation
increases only the value of the land. A more direct and efficient way to fund
transportation projects is to tax land at a higher rate than buildings. The lower
tax on buildings would allow owners to retain more of the profits of their investment
in construction, and would be expected to lead to higher development intensity.
A partial equilibrium simulation is created for Minneapolis, Richfield and Bloomington,
Minnesota to determine the intensity effects of various levels of split-rate
property taxes for both residential and nonresidential development. The results
indicate that split-rate taxes would lead to higher densities for both types
of development in all three cities.
JEL code: R51, R52, R48, H23, H27, H71, R14, R21, R33
Keywords: tax, land value, locational analysis, transportation finance Journal of Transport and Land Use 5(1) pp.49-63 [poster] [doi]
- Junge, Jason and David Levinson (2012)
Prospects for transportation utility fees.
Transportation utility fees are a transportation financing mechanism in
which the network is treated as a utility and properties are charged fees in
proportion to their network use, rather than according to their monetary value
as in property taxation. This mechanism connects the costs of maintaining the
infrastructure more directly to the benefits received from mobility and access
to the system. The fees are based on the number of trips generated and vary with
land use. This paper evaluates transportation utility fees as an alternative
funding source in terms of efficiency, equity, revenue adequacy and political
and administrative feasibility. The experiences of cities currently using utility
fees for transportation are discussed. Calculations are included to determine
the fee levels necessary for transportation maintenance budget needs in three
sample cities and a county in the Minneapolis-St. Paul (USA) metropolitan area.
Proposed fees for each property type are compared to current property tax contributions
toward transportation. The regressive effects of the fees and the effect of adjusting
for the length of trips generated are also quantified.
JEL code: H71, L91, R48, R51, R52
Keywords: tax, land value, locational analysis, transportation finance Journal of Transport and Land Use 5(1) pp. 33-47 [presentation] [doi]
- Krizek, Kevin J. and David Levinson (2012) Access. The Oxford Handbook of Urban and Regional Planning. Editors Rachel Weber and Randall Crane. Chapter 9; pages 166-180. Oxford University Press, New York.
- Levinson, David (2012)
Accessibility Impacts of High Speed Rail
This paper reviews the state of high-speed rail (HSR) planning in the United States c. 2010. The plans generally call for a set of barely inter-connected hub-and-spoke networks. The evidence from US transit systems shows that lines have two major impacts. There are positive accessibility benefits near stations, but there are negative nuisance effects along the lines themselves. High speed lines are unlikely to have local accessibility benefits separate from connecting local transit lines because there is little advantage for most people or businesses to locate near a line used infrequently (unlike public transit). However they may have more widespread metropolitan level effects. They will retain, and perhaps worse, have much higher, nuisance effects. If high-speed rail lines can create larger effective regions, that might affect the distribution of who wins and loses from such infrastructure. The magnitude of agglomeration economies is uncertain (and certainly location-specific), but presents the best case that can be made in favor of HSR in the US.
JEL code: R40, R11, R14
Keywords: high-speed rail, public transportation, economic development, land use, hub-and-spoke Journal of Transportation Geography Vol 22 May 2012. pp. 288-291 [doi]
- Levinson, David (2012) Network Structure and City Size.
Network structure varies across cities. This variation may yield important knowledge about how the internal structure of the city affects its performance. This paper systematically com- pares a set of surface transportation network structure variables (connectivity, hierarchy, circuity, treeness, entropy, accessibility) across the 50 largest metropolitan areas in the United States. A set of scaling parameters are discovered to show how network size and structure vary with city size. These results suggest that larger cities are physically more inter-connected. Hypotheses are presented as to why this might obtain. This paper then consistently measures and ranks access to jobs across 50 US metropolitan areas. It uses that accessibility measure, along with network structure variables and city size to help explain journey-to-work time and auto mode share in those cities. A 1 percent increase in accessibility reduces average metropolitan commute times by about 90 seconds each way. A 1 percent increase in network connectivity reduces commute time by 0.1 percent. A 1 percent increase in accessibility results in a 0.0575 percent drop in auto mode share, while a 1 percent increase in treeness reduces auto mode share by 0.061 percent. Use of accessibility and network structure measures is important for planning and evaluating the performance of network investments and land use changes.
Keywords: Connectivity, Network Structure, Transportation Geography, Network Science, City Size, Scaling Rules, Accessibility, Travel Behavior, Mode Share, Journey-to-Work PLoS One 7(1): e29721 [doi]
- Levinson, David and Arthur Huang (2012)
A Positive Theory of Network Connectivity.
This paper develops a positive theory of network connectivity, seeking to explain the micro-foundations of alternative network topologies as the result of self-interested actors. By building roads, landowners hope to increase their parcels’ accessibility and economic value. A simulation model is performed on a grid-like land use layer with a downtown in the center, whose structure resembles the early form of many Midwest- ern and Western (US) cities. The topological attributes for the networks are evaluated. This research posits that road networks experience an evolutionary process where a tree-like structure first emerges around the centered parcel before the network pushes outward to the periphery. In addition, road network topology undergoes clear phase changes as the economic values of parcels vary. The results demonstrate that even without a centralized authority, road networks have the property of self-organization and evolution, and, that in the absence of intervention, the tree-like or web-like nature of networks is a result of the underlying economics.
JEL code: R41, R48, R53
Keywords: road network, land parcel, network evolution, network growth, phase change, centrality measures, degree centrality, closeness centrality, betweenness centrality, network structure, treeness, circuitness, topology Environment and Planning Part B 39(2), pp. 308 -- 325. [doi] [poster]
- Levinson, David, Feng Xie, Norah Montes de Oca (2012) Forecasting and Evaluating Network Growth. Abstract: This research assesses the implications of existing trends on future network investment, comparing alternative scenarios concerning budgets and investment rules across a variety of performance measures. The main scenarios compare stated decision rules processes encoded in flowcharts and weights developed from official documents or by discussion with agency staff, with revealed decision rules, weights estimated statistically based on observed historical behavior. This research specifies the processes necessary to run the network forecasting models with various decision rules. Results for different scenarios are presented including adding additional constraints for the transportation network expansion and calibration process details. We find that alternative decision rules make only small differences in overall system performance, though they direct investments to very different locations. However, changes in total budget can make a significant difference to system-wide performance. Networks and Spatial Economics 12(2) 239--262 [presentation] [doi]
- Levinson, David and Shanjiang Zhu (2012)
The Hierarchy of Roads, the Locality of Traffic, and Governance
This study investigates the usage of road networks both within and outside of home jurisdictions (city (or town) and county of residence) by analyzing GPS data collected in the Minneapolis - Saint Paul metropolitan area, which tracked volunteers’ travel behavior to determine which roads (and thus which class of roads) users chose to accommodate their travel needs. More than half of the travel on county roads and city streets occur outside of one’s home city, but most travel is within one’s home county. The average share of travel distance in the home county is more than 70% for both county and city streets. The high share, which does not even account for non-residents destined for the county to work or shop, e.g., implies that the free rider problem on city and county streets at the county level is minimal. Of particular con- cern is travel on city roads in cities other than one’s own. To the extent that this is to go to a destination in that city, that travel is also local. However, because city and county roads are typically funded by those jurisdictions from land-based sources such as property taxes, through trips with neither end in the city through which they are traveling are in a very real sense "free riders", and pose a problem. With growing trip lengths and emerging economies of scale in road management, it may be appropriate to consider moving more roads from township, town, or city level to the county level of government.
JEL code: R41, R48, R53
Keywords: Transportation financing, GPS, road utilization, hierarchy of roads, transportation governance Transport Policy 19 (2012) 147-154. [doi] [poster]
- Parthasarathi, Pavithra, Hartwig Hochmair, and David Levinson (2012)
Network Structure and Spatial Separation.
The objective of this research is to identify the role of network architecture in influencing individual travel behavior using travel survey data from two urban areas in Florida: Fort Lauderdale and Miami. Various measures of network structure, compiled from existing sources, are used to quantify roadway networks, capture the arrangement and connectivity of nodes and links in the networks and the temporal and spatial variations that exist among and within networks. The results from the regression models estimated show that network design influences how people travel and make decisions. Results from this analysis can be used to understand how changes in network can be used to bring about desired changes in travel behavior.
JEL code: R41, R42, R48, D85, R14, R52
Keywords: Network structure, travel behavior, transport geography, commuting, circuity Environment and Planning B: Planning and Design 39(1) 137-154 [doi].
- Wasfi, Rania A., David Levinson and Ahmed M. El-Geneidy, (2012) The
Transportation Needs of Seniors. Over 208,000 residents of Hennepin
County, Minnesota are over the age of 55, a number that is sure to
rise. This paper examines the transportation needs of the elderly in
Hennepin County through a mail out-mail back survey of their existing
travel behavior and their unmet needs. The survey had both demographic
and attitude questions as well as a travel diary for recording actual
trips and desired but untaken trips. We found that 87% of the sampled
population feel they are independent travelers. Around 51 percent of
the surveyed population indicated that they are transit users, 25 percent
of them revealed their concerns about difficulties they are facing
when using public transit. About 16 percent of transit users were concerned
about waiting time for transit, while only 8% were concerned about
the travel time. Only 15 percent of the surveyed population use paratransit.
A large number of comments were received, which add qualitative flavor
to the analysis that was conducted. Seniors recognize even if they
are currently independent, that will not always be the case, and acknowledge
they should plan.
Keywords: Transportation needs, Elderly, Seniors, Disadvantaged Populations Journal of Transportation Literature / Revista de Literatura dos Transportes 6(2) pp.8-32
- Carrion, Carlos and David Levinson (2011)
A Model of Bridge Choice Across the Mississippi River in Minneapolis
On September 18th 2008, a replacement for the previously collapsed I-35W bridge opened to the public. Consequently, travelers were once again confronted with the opportunity to find better alternatives. The traffic pattern of the Minneapolis road network was likely to readjust, because of the new link addition. However, questions arise about the possible reasons (or components in the route choice process) that are likely to influence travelers crossing the Mississippi, who had to choose among the bridge options, including the new I-35W bridge. Using GPS data and web-based survey collected both before and after the replacement bridge opened, a bridge choice model is estimated using weighted-least squares logit. In this way the proportion of I-35W trips can be estimated depending on the assigned values of the explanatory variables, which include: statistical measures of the travel time distribution experienced by the subjects, alternative diversity, and others. The results showed that travel time savings and reliability were the main reasons for choosing the new I-35W bridge.
JEL code: R41, R48, R53
Keywords: I-35W Mississippi River Bridge, Route Choice, Route Assignment, Traffic Assignment, Discrete Choice Published in Network Reliability in Practice. Edited by David Levinson, Henry Liu, and Michael Bell. pp. 115-130. Springer
- Chi, Guangqing, Xuan Zhou, Timothy E. McClure, Paul A. Gilbert, Arthur G. Cosby, Li Zhang, Angela A. Robertson, David Levinson (2011)
Gasoline Prices and Their Relationship to Drunk-Driving Crashes.
This study investigates the relationship between changing gasoline prices and drunk-driving crashes. Specifically, we examine the effects of gasoline prices on drunk-driving crashes in Mississippi by age, gender, and race from 2004–2008, a period experiencing great fluctuation in gasoline prices. An exploratory visualization by graphs shows that higher gasoline prices are generally associated with fewer drunk-driving crashes. Higher gasoline prices depress drunk- driving crashes among younger and older drivers, among male and female drivers, and among white, black, and Hispanic drivers. The statistical results suggest that higher gasoline prices lead to lower drunk-driving crashes for female and black drivers. However, alcohol consumption is a better predictor of drunk-driving crashes, especially for male, white, and older drivers.
JEL code: R41, R48, Q41, R51
Keywords: Drunk-driving crashes, gasoline prices, alcohol consumption, Mississippi Accident Analysis and Prevention, [doi] 43(1) January 2011, Pages 194-203.
- El-Geneidy, A. and David Levinson (2011)
Place Rank: Valuing Spatial Interactions.
Accessibility measures the potential of opportunities for interaction. This paper proposes and explores a new flow-based measure, 'place rank' using origin-destination information. Both impedance and value of opportunities are embedded in the dataset that includes the origin and destination of each person within the studied region. Individuals contribute to the place rank at their destination (work) zone with a power that depends on the attractiveness of the zone of origin. In this paper we demonstrate this place rank measure for three activities (Jobs, Resident Workers, and Health Services) in the Minneapolis-St. Paul metropolitan region and Jobs in Montreal, Canada. We compare place rank to traditional measures of accessibility. Since place rank is based on actual choices of origins and destinations it is a measure of realized rather than potential opportunities, and so unlike accessibility measures. Also it does not require the knowledge of travel time between all origins and destinations.
Keywords: Accessibility, Mobility, Gravity Based, Cumulative Opportunity, Land Use, Place Rank Networks and Spatial Economics 11(4) pp. 643-659 [doi]
- Huang, Arthur and David Levinson (2011)
Why retailers cluster: An agent model of location choice on supply chains. This paper investigates the emergence of retail clusters on supply chains comprised of suppliers, retailers, and consumers. Agent-based models are employed to study retail location choice in a market of homogeneous goods and a market of complementary goods. On a circle comprised of discrete locales, retailers play a non-cooperative game by choosing locales to maximize profits which are impacted by their distance to consumers and to suppliers. Our findings disclose that in a market of homogeneous products symmetric distributions of retail clusters rise out of competition between individual retailers; average cluster density and cluster size change dynamically as retailers enter the market. In a market of two complementary goods, multiple equilibria of retail distributions are found to be common; a single cluster of retailers has the highest probability to emerge. Overall, our results show that retail clusters emerge from the balance between retailers’ proximity to their customers, their competitors, their complements, and their suppliers.
JEL code: R30, L22
Keywords: retail clusters, agent-based model, location choice, distribution pattern Environment and Planning b 38(1) pp. 82 – 94 [doi] [poster]
- Iacono, Michael and David Levinson (2011) Location, Regional Accessibility and Price Effects: Evidence from Home Sales in Hennepin County, Minnesota. Regional location factors, with measures of regional accessibility foremost among them, exert a strong influence on urban property markets. While accessibility represents an important regional-scale factor, more local influences such as proximity to urban highway links may also positively or negatively influence the desirability of a location. In this paper, we use a cross-section of home sales in Hennepin County, Minnesota from the years 2001 through 2004, along with a set of disaggregate regional accessibility measures, to estimate the value of access to employment and resident workers. We also estimate the (dis)amenity effects of locations near major freeway links that have recently undergone, or were scheduled to undergo (as of the time period covered by the home sales), major construction to add capacity. The richness of the home sales data set allows us to control for a number of structural attributes, as well as some site characteristics, while additional neighborhood characteristics (such as income levels and local educational quality) are added from supplemental data sources. Empirical results indicate that households highly value employment access, while access to other resident workers (i.e. competition for jobs) is considered a disamenity. Proximity to local highway access points is positively associated with sale price, while proximity to the highway link itself is negatively associated with price. The paper concludes with some implications for research and practice of the concept and measurement of the relationship between location and land value.
JEL code: R41, R48, R53
Keywords: Transportation – Economics, Land Value, Accessibility, Hennepin County (MN) Transportation Research Record: Journal of the Transportation Research Board #2245 pp.87-94 [doi]
- Jenelius, E., Mattsson, L.-G. and Levinson, D. (2011),
The traveler costs of unplanned transport network disruptions: An activity-based modeling approach,
Abstract: The delay costs of traffic disruptions and congestion and the value of travel time reliability are typically evaluated using single trip scheduling models, which treat the trip in isolation of previous and subsequent trips and activities. In practice, however, when activity scheduling to some extent is flexible, the impact of delay on one trip will depend on the actual and predicted travel time on itself as well as other trips, which is important to consider for long-lasting disturbances and when assessing the value of travel information. In this paper we extend the single trip approach into a two trips chain and activity scheduling model. Preferences are represented as marginal activity utility functions that take scheduling flexibility into account. We analytically derive trip timing optimality conditions, the value of travel time and schedule adjustments in response to travel time increases. We show how the single trip models are special cases of the present model and can be generalized to a setting with trip chains and flexible scheduling. We investigate numerically how the delay cost depends on the delay duration and its distribution on different trips during the day, the accuracy of delay prediction and travel information, and the scheduling flexibility of work hours. The extension of the model framework to more complex schedules is discussed.
- Extends single-trip modeling approach for value of reliability and delay costs.
- Trip chain and activities model with scheduling flexibility.
- Derives values of travel time and schedule adjustments in response to journey delay.
- Shows single trip scheduling models are special cases.
- Handles imperfect delay prediction, information and long-lasting disruptions.
Keywords:Congestion; Disruption; Delay cost; Reliability; Schedule; Value of time
JEL-Code: R41, R48, D63 Transportation Research part B 45(5) pp. 789-807. [doi]
- Levinson, David and Feng Xie (2011) Does
First Last? The existence and extent of first mover advantages on spatial
networks. This paper examines the nature of first mover advantages
on spatially- differentiated surface transportation networks. The literature
on first mover advantages identifies a number of sources that explain
their existence. However whether those sources exist on spatial networks,
and how they play out with true capital immobility have been unanswered
questions. By examining empirical examples including commuter rail
and the Underground in London and roads in the Twin Cities of Min-
neapolis and St. Paul, first mover advantages were observed in rail
stations but not in the road network. A simulation model was then constructed
to replicate the growth of surface transportation networks incorporating
idealized deployment decisions and to test whether the first network
elements (links, nodes) remain strongest (or even strong) into the
future. Simulation experiments were conducted and Spearman rank correlation
tests revealed that first mover advantages exist in both nodes and
links and become increasingly prominent as the network evolves due
to the accumulated advantage of earlier established network elements.
Simulation results also disclosed that network growth with a higher
concentration of initial land uses results in stronger first mover
advantages, and that the extent may vary as the topological attributes
of the network change over time. The sensitivity of simulation results
on model parameters are also discussed.
Keywords: first mover advantage, transport, land use, London Underground, London railways, network growth, induced demand, induced supply Journal of Transport and Land Use 4(2) pp. 47-69
- Parthasarathi, Pavithra, Anupam Srivastava, Nikolas Geroliminis, and
David Levinson (2011) The
Importance of Being Early. The assumption that the penalty for
being early is less than that for being late was put forward by Vickrey
who analyzed how commuters compare penalties in the form of schedule
delay (due to peak hour congestion), against penalties in the form of
reaching their destination (ahead or behind their desired time of arrival).
This assumption has been tested by many researchers since then for various
applications, especially in modeling congestion pricing where it is critical
to understand the tradeoff between schedule delay and travel delay. Key
ﬁndings are summarized in the second section of this paper. This research
aims to test this hypothesis of earliness being less expensive than lateness
using empirical data at different levels and across different regions.
New methods to estimate the ratio of earliness to lateness for different
types of datasets are developed, which could be used by agencies to implement
control policies like congestion pricing or other schemes more accurately.
Travel survey data from metropolitan areas provide individual travel
patterns while loop detector data provide link level traffic ﬂow data.
Keywords: Schedule Delay, Value of Time, Travel Behavior, Transportation Planning Transportation 38(2) pp. 227-247 [doi]
- Tilahun, Nebiyou and David Levinson (2011) Work and Home Location: Possible Role of Social Networks. This research explores to what extent people’s work locations are similar to that of those who live around them. Using the Longitudinal Economic and Household Dynamics data set and the US census for the Twin Cities (Minneapolis-St. Paul) metropolitan area, we investigate the home and work locations of different census block residents. Our aim is to investigate if people who live close to one another, also work close to one another to a degree beyond what would be expected at random. We find a significantly non-random correlation between joint home and joint work locations. Further, we show what features of particular neighborhoods are associated with comparatively higher incidences of people sharing work locations. One reason for such an outcome can be the role neighborhood level social networks play in locating jobs; or conversely work place social networks play in choosing the home location or both. Such findings should be used to refine work trip distribution models that otherwise depend mainly on impedance between the origin and destination Transportation Research part A 45(40) pp. 323-331 [doi]
- Xie, Feng and David Levinson (2011) Evaluating
the Effects of I-35W Bridge Collapse on Road-Users in the Twin Cities
Metropolitan Region. This study evaluates the effects of I-35W
bridge collapse on road-users in the Twin- Cities metropolitan area.
We adopted the Twin-Cities (Metropolitan Minneapolis and St. Paul)
Seven-County travel demand model developed in previous research, re-calibrated
it against July 2007 loop detector traffic data, and used this model
to carry out an evaluation of economic loss incurred by increased travel
delay in alternative scenarios before and after the bridge collapse.
We concluded that the failure of the I-35W bridge resulted in an economic
loss of $71,000 to $220,000 a day, depending on how ﬂexible road-users
in the system can adjust their trip destinations in response to the
bridge closing. We also estimated that the ma jor traffic restoration
projects Mn/DOT has implemented in quick response to the bridge collapse
can save road-users $9,500 to $17,500 a day. This translates into a
beneﬁt-cost ratio of 2.0-9.0, suggesting these pro jects are highly
beneﬁciary in an economic sense. In this analysis, the use of a simpliﬁed,
scaled-down travel demand model enabled us to carry out the analysis
quickly and accurately, showing its contributions in transportation
planning under situations such as emergency relief and comprehensive design.
Keywords: I-35W Bridge Collapse, Twin Cities (Minnesota), economic evaluation Transportation Planning and Technology 34(7) pp. 691-703. [doi] [bib] [presentation]
- Zhu, Shanjiang, Feng Xie and David Levinson (2011) Enhancing
Transportation Education through On-line Simulation using an Agent-Based
Demand and Assignment Model. This research explores the effectiveness
of using simulation as a tool for enhancing classroom learning in the
Civil Engineering Department of the University of Minnesota at Twin
Cities. The authors developed a modern transportation planning software
package, Agent-based Demand and Assignment Model (ADAM), that is consistent
with our present understanding of travel behavior, that is platform
independent, and that is easy to learn and is thus usable by students.
An in-class project incorporated ADAM and the performance of this education
strategy was evaluated through pre-class survey, post-class survey,
scores in the quiz focusing on travel demand modeling and final scores.
Results showed that ADAM effectively enhanced students' self-reported
understanding of transportation planning and their skills of forming
opinions, evaluating projects and making judgments. Students of some
learning styles were found to benefit more than others through simulation-based
teaching strategy. Findings in this research could have significant
implications for future practice of simulation-based teaching strategy.
Keywords: Agent-based Model, Transportation Education, Simulation ASCE Journal of Professional Issues in Engineering Education and Practice 137(1) pp. 38-45 [doi]
- Zhu, Shanjiang and David Levinson (2011)
Disruptions to Transportation Networks: A Review.
Travel decisions may be very stable in a familiar environment. Major network disruptions such as the I-35W bridge collapse disrupt habitual behavior. Such ``natural'' experiments provide unique opportunities for behavioral studies, but the time window for such studies is limited. A well-developed methodology is crucial for both data collection and analysis, and thus the soundness of behavioral models , especially in such a limited time window. Therefore, this paper reviews both theoretical and empirical studies on traffic and behavioral impacts of network disruptions. Findings from this paper offers prospective ideas about capturing the impacts of network disruption.
JEL code: R41, R48, D83, C99
Keywords: Network disruption, travel behavior, web-based survey Published in Network Reliability in Practice Edited by David Levinson, Henry Liu, and Michael Bell. pp. 5-20.
- Zhu, Shanjiang, Nebiyou Tilahun, David Levinson, and Xiaozheng He (2011)
Travel Impacts and Adjustment Strategies of the Collapse and the Reopening of the I-35W Bridge.
Major network disruptions have significant impacts on local travelers. A good understanding of behavioral reactions to such incidents is crucial for traffic management and planning. Existing research on such topics is limited. This study investigates travelers’ reaction to both the collapse and reopening of the I-35W Bridge crossing the Mississippi River at the Twin Cities, Minnesota. A web-based survey conducted at residences in several communities across the metropolitan area supplements the hand-
out/mail-back paper-based survey distributed to workers in areas around the bridge collapse (downtown Minneapolis and the University of Minnesota). findings from the survey highlight differences in travel impacts and behavioral reactions after the bridge collapse and the bridge reopening.
JEL code: R41, R48, D83, C99
Keywords: Network disruption, travel behavior, web-based survey Published in Network Reliability in Practice Edited by David Levinson, Henry Liu, and Michael Bell. pp. 21-36.
- Chi, Guangqing, Arthur Cosby, Mohammed A. Quddus, Paul Gilbert and David Levinson (2010)
Gasoline Prices and Traffic Safety: Age and Gender Variations.
Gasoline prices have significant effects on traffic safety. However, existing literature has failed to adequately investigate the effects: the literature has examined only fatal incidents rather than total traffic incidents. This study analyzes the effects of gasoline prices on total traffic incidents and on the incidents by age and gender. The results suggest that gasoline prices have negative short-term effects on traffic safety: as gasoline prices increase, overall traffic incident rates decrease. Gasoline prices have disproportionate effects in reducing traffic incident rates for young drivers and female drivers, longer-term effects on drivers who are 24 years and older, and no effects on male drivers. This study fills the gap in the literature by contributing to the understanding of gasoline price effects on traffic incidents by examining all traffic incidents instead of only fatal incidents and by examining incidents by age and gender.
JEL code: R41, R48, Q41, R51
Keywords: gasoline prices, traffic incidents, traffic safety, age, gender Journal of Safety Research 41 493–500.
- Huang, Arthur and David Levinson (2010)
The Effects of Daylight Saving Time on Vehicle Crashes in Minnesota
Daylight saving time (DST), implemented as an energy saving policy, impacts many other aspects of life; one is road safety. Based on vehicle crash data in Minnesota from 2001 to 2007, this paper evaluates long- and short-term effects of DST on daily vehicle crashes. To provide evidence to explain the causes of more/fewer crashes in DST, we examine the impact of DST on crashes in four periods of a day: 3 am-9 am, 9 am-3 pm, 3 pm-9 pm, 9 pm-12 pm. The effects of risk and exposure to traffic are also separated. Our statistical models not only include weather conditions and dummy variables for days in DST as independent variables, but also consider traffic volumes on major roads in different periods of a day. Our major finding is that the short-term effect of DST on crashes on the morning of the first DST is not statistically significant. Moreover, it is interesting to notice that while DST per se is associated with fewer crashes during
dusk, this is in part offset because it is also associated with more traffic on roads (and hence more crashes). Our path analysis shows that overall DST reduces crashes.
JEL-Code: R41, R48, D63
Keywords: daylight saving time, vehicle crashes, exposure, fatal crashes, traffic volume, Minnesota Journal of Safety Research 41 513-520. [doi] [poster]
- Levinson, David (2010) Equity
Effects of Road Pricing: A Review. Are road pricing strategies
regressive or progressive? This is a question that has been confronting
researchers, practitioners, and policy-makers who seek to implement
new mechanisms to raise funds for transportation while simultaneously
managing demand. The theoretical literature is mixed, as is the empirical
literature. In part this has to do with the various types of road pricing
strategies that are being debated, different definitions of equity,
and alternative assumptions about revenue recycling. Despite this seeming
complexity, the literature is clear that equity issues are addressable.
This paper provides a synthesis of the literature to date on both the
theory of equity, as applied to road pricing, and the findings of empirical
and simulation studies of the effects of particular implementations
of road pricing, and suggested remedies for real or perceived inequities.
To summarize, while there are certainly potential issues with equity
associated with road pricing, those issues can be addressed with intelligent
mechanism design that provides the right incentives to travelers and
uses the raised revenues in a way to achieve desired equitable ends.
These include cutting other taxes and investing in infrastructure and
Keywords: road pricing, equity, welfare, tolling, toll roads. Transport Reviews 30(1) 33-57. [bib] [doi]
- Parthasarathi, Pavithra and David Levinson (2010) Post-Construction
Evaluation of Trafﬁc Forecast Accuracy. This research evaluates
the accuracy of demand forecasts using a sample of recently-completed
projects in Minnesota and identiﬁes the factors inﬂuencing the inaccuracy
in forecasts. The fore- cast trafﬁc data for this study is drawn from
Environmental Impact Statements(EIS), Transporta- tion Analysis Reports
(TAR) and other forecast reports produced by the Minnesota Department
of Transportation (Mn/DOT) with a horizon forecast year of 2010 or
earlier. The actual trafﬁc data is compiled from the database of trafﬁc
counts maintained by the Ofﬁce of Trafﬁc Forecasting and Analysis section
at Mn/DOT. Based on recent research on forecast accuracy, the (in)accuracy
of trafﬁc forecasts is estimated as a ratio of the forecast trafﬁc
to the actual trafﬁc. The estimation of forecast (in)accuracy also
involves a comparison of the socioeconomic and demographic assumptions,
the assumed networks to the actual in-place networks and other travel
behavior assumptions that went into generating the trafﬁc forecasts
against actual conditions. The analysis indicates a general trend of
underestimation in roadway trafﬁc forecasts with fac- tors such as
highway type, functional classiﬁcation, direction playing an inﬂuencing
role. Road- ways with higher volumes and higher functional classiﬁcations
such as freeways are subject to underestimation compared to lower volume
roadways/functional classiﬁcations. The comparison of demographic forecasts
shows a trend of overestimation while the comparison of travel behavior
characteristics indicates a lack of incorporation of fundamental shifts
and societal changes.
Keywords: Traffic Forecast, Travel Demand Model, Transportation Planning Transport Policy 17 (2010) p. 428-443 [bib] [presentation] [doi]
- Tilahun, Nebiyou Jonas, and David Levinson (2010) A
Moment of Time: Reliability in Route Choice using Stated Preference. Abstract:
Understanding how reliability is valued is important because it provides
insight to how aims of policies that aspire to provide better transport
options can be more fully integrated with user expectations. In this
study we derive a choice model for work commute trips that trades off
alternatives based on the most frequent experience that users had on
that route and the possibility of late or early arrival if they use
a particular route. The idea of reliability is incorporated by how
far the expected lateness or early arrival is from the most frequent
experience on that route. We find that on route decisions the mode
travel time is valued at $7.43 per hour while reduction from the magnitude
of average lateness (thereby increasing the reliability of the route)
is valued at $6.91 per hour.
Keywords: Travel time reliability, Stated preference, Late Penalty, Early Penalty Journal of Intelligent Transportation Systems 14: 3, 179 — 187. [bib] [presentation] [doi]
- Xie, Feng and David Levinson (2010) How
Streetcars Shaped Suburbanization: A Granger-Casality Analysis of Land
Use and Transit in The Twin Cities. This paper presents a causality
analysis of the coupled development of population and streetcars in
the Twin Cities metropolitan area. Historic residence and network data
were assembled for 1900-1930, and linear cross-sectional time-series
models were estimated at both a tract and block level using this data.
It is found that, in contrast with transportation systems that were
expanded in response to increased demand, the rapid expansion of the
streetcar system during the electric era has been driven by other forces
and to a large extent led land development in the Twin Cities. The
main forces that have driven this process include technological superiority,
monopoly, close con- nections with real estate business, and people’s
reliance on the streetcar for mobility. Proximity to the streetcar
is found to be a crucial factor that determines the distribu- tion
and development of residences: it is observed that residential density
declines with the distance from streetcar lines, and signiﬁcantly drops
beyond a walkable distance; it is also observed that gaining a closer
access to streetcar lines within 800 meters (about a half mile) predicts
the increase in residential density to a signiﬁcant extent.
Keywords: streetcars, light rail transit, land use and transportation, development, Twin Cities (Minnesota), network growth Journal of Economic Geography 10(3), pp. 453-470 [bib] [presentation] [doi]
- Zhang, Lei and David Levinson (2010). Ramp
Metering and Freeway Bottleneck Capacity. Abstract: This study aims to determine whether ramp meters increase the capacity of active freeway bottlenecks. The traffic flow characteristics at twenty-seven active bottlenecks in the Twin Cities have been studied for seven weeks without ramp metering and seven weeks with ramp metering. A methodology for systematically identifying active freeway bottlenecks in a metropolitan area is proposed, which relies on two occupancy threshold values and is compared to an established diagnostic method – transformed cumulative count curves. A series of hypotheses regarding the relationships between ramp metering and the capacity of active bottlenecks are developed and tested against empirical traffic data. It is found that meters increase the bottleneck capacity by postponing and sometimes eliminating bottleneck activations, accommodating higher flows during the pre-queue transition period, and increasing queue discharge flow rates after breakdown. Results also suggest that flow drops after breakdown and the percentage flow drops at various bottlenecks follow a normal distribution. The implications of these findings on the design of efficient ramp control strategies are discussed, as well as future research directions.
Keywords: Ramp metering, highway capacity, active bottleneck, queue discharge flow, Twin Cities ramp meter shut-off Transportation Research: A Policy and Practice 44(4), May 2010, pp. 218-235. [bib][doi]
- Zhu, Shanjiang, David Levinson, Henry Liu, and Kathleen Harder (2010) The
Traffic and Behavioral Effects of the I-35W Mississippi River Bridge collapse. On August 1, 2007, the collapse of the I-35W bridge over the Mississippi River in Minneapolis abruptly interrupted the usual route of about 140,000 daily vehicle trips, which substantially disturbed regular traffic flow patterns on the network. It took several weeks for the network to re-equilibrate, during which period, travelers continued to learn and adjust their travel decisions. A good understanding of this process is crucial for traffic management and the design of mitigation schemes. Data from loop detectors, bus ridership statistics, and a survey are analyzed and compared reveal the evolving traffic reactions to the bridge collapse and how individual choices could help to explain such dynamics. Findings on short-term traffic dynamics and behavioral reactions to this major network disruption have important implications for traffic management in response to future scenarios.
Keywords: I-35W bridge collapse, travel behavior, travel survey Transportation Research part A 44(10), Dec 2010, pp. 771-784 [ doi] [bib] [poster]
- Corbett, Michael, Feng Xie, and David Levinson (2009) Evolution
of the Second-Story City: The Minneapolis Skyway System. This
paper describes and explains the growth of the Minneapolis Skyway network.
Accessibility is used as a major factor in understanding that growth
(i.e. does the network connect to the location(s) with the highest
accessibility, followed by the second highest, and so on). First, employment
opportunities are used as the measure of activity and are based off
of the square footage of buildings and/or ITE trip generation rates.
Using information about the buildings located downtown for each year
since the first skyway was built, the accessibilities of each of the
connected and adjacent unconnected blocks were calculated for every
time period the skyway system expanded. The purpose is to determine
how often the expansion connected the block with the highest accessibility.
The results show that though important, accessibility was rarely maximized,
except in the early stages of development. A connect-choice logit model
relating the probability of joining the network (in a given year) to
accessibility and network size was employed. The results show accessibility
does remain an important factor in predicting which links are connected.
Physical difficulties in making connections may have played a role,
as well as the potential for adverse economic impacts.
Keywords: Network growth, Skyways, Minneapolis Environment and Planning b 36(4) 711-724 [doi]
- Geroliminis, Nikolas and David Levinson (2009)
Cordon Pricing Consistent with the Physics of Overcrowding.
This paper describes the modeling of recurring congestion in a network. It is shown that the standard
economic models of marginal cost cannot describe precisely traffic congestion in networks during time-dependent
conditions. Following a macroscopic traffic approach, we describe the equilibrium solution for a congested network
in the no-toll case. A dynamic model of cordon-based congestion pricing (such as for the morning commute) for
networks is developed consistent with the physics of traffic. The paper combines Vickrey’s theory with a
macroscopic traffic model, which is readily observable with existing monitoring technologies. The paper also
examines some policy implications of the cordon-based pricing to treat equity and reliability issues, i.e. in what
mobility level a city should choose to operate. An application of the model in a downtown area shows that these
schemes can improve mobility and relieve congestion in cities.
Keywords: congestion pricing, traffic models, macroscopic fundamental diagram Published in Transportation and Traffic Theory 2009: Golden Jubilee. (ed. William H. K. Lam, S. C. Wong and Hong K. Lo) pp. 219--240. Springer. [doi]
- Huang, Arthur and David Levinson (2009)
Retail Location Choice with Complementary Goods: An Agent-based Model.
This paper models the emergence of retail clusters on a supply chain network comprised of suppliers, retailers, and consumers. Firstly, an agent-based model is proposed to investigate retail location distribution in a market of two complementary goods. The methodology controls for supplier locales and unit sales prices of retailers and suppliers, and a consumer’s willingness to patronize a retailer depends on the total travel distance of buying both goods. On a circle comprised of discrete locations, retailers play a non-cooperative game of location choice to maximize individual profits. Our findings suggest that the probability distribution of the number of clusters in equilibrium follows power law and that hierarchical distribution patterns are much more likely to occur than the spread-out ones. In addition, retailers of complementary goods tend to co-locate at supplier locales. Sensitivity tests on the number of retailers are also performed. Secondly, based on the County Business Patterns (CBP) data of Minneapolis-St. Paul from US Census 2000 database, we find that the number of clothing stores and the distribution of food stores at the zip code level follows power-law distribution.
JEL code: R30, L22
Keywords: clustering, agent-based model, location choice, power-law distribution pattern, retailing in Complex Sciences: First International Conference, Complex 2009, Shanghai, China, February 23-25, 2009. Revised Papers, Part 1. (Lecture Notes of the Institute for Computer Sciences, Social Informatics, and Telecommunications Enginering) (ed. Jie Zhou). [doi]
- Iacono, Michael and David Levinson (2009) Predicting
Land Use Change: How Much Does Transportation Matter? In this
paper, we propose to measure the extent of the inﬂuence of transportation
systems on land use change. Using a set of high-resolution land use
data for the Twin Cities metropolitan region, we estimate logistic
regression models of land use change covering a 10-year period from
1990 to 2000. The models account for existing land use types, neighboring
land uses, and transportation network variables that measure the physical
proximity of highway networks, as well as the level of accessibility
associated with a speciﬁc location. The models are esti- mated with
and without the transportation variables and compared to assess the
extent of their inﬂuence. We ﬁnd (perhaps not surprisingly) that transportation-related
variables exert some inﬂuence on changes to land use patterns, though
not as much as variables representing existing and neighboring land
Keywords: Land use, Twin Cities (Minnesota), Mathematical models, urban growth Transportation Research Record 2119: 130-136 [doi] [bib] [poster].
- Levinson, David (2009) Network Neutrality: Lessons from Transportation. The politically-charged notion of network neutrality came to the fore in 2005 and 2006, using analogy from transportation as one of the key tools in motivating arguments. This paper examines how the various notions around network neutrality (common carriage, regulation, price discrimination) have played out in the transportation sector, and suggests many of the current arguments fail to understand the nuances of how complex networks actually operate to serve the many demands placed on them. Review of Network Economics 8(1) 13-21 [download].
- Levinson, David and Ahmed El-Geneidy (2009) The
Minimum Circuity Frontier and the Journey to Work. People travel
between places of residence and work destinations via transportation
networks. The relation between selection of home and work locations
has been heavily debated in the transportation planning literature.
In this paper we use circuity, the ratio of network to Euclidean distance,
to better understand the choice of residential location relative to
work. This is done using two methods of defining origins and destinations
in twenty metropolitan regions in the United States, with more detailed
analysis of Minneapolis–St. Paul, Minnesota and Portland, Oregon. The
first method of selection is based on actual choice of residence and
work locations. The second is based on a randomly selected dataset
of origins and destinations in the same regions, followed by a comparison
between the two methods for these regions. The study shows circuity
measured through randomly selected origins and destinations differs
from circuity measured from actual origins and destinations. Workers
tend to reside in areas such that the journey to work circuity is lower
than random, applying intelligence to their location decisions. Consistent
with traditional urban economic theory, this suggests locators wish
to locate on the frontier with the largest residential lot at the shortest
commute time, but in contrast with the classic model which simplifies
transportation networks to be uniform, we cannot assume that all possible
home–work pairs are on the frontier. This finding, developed from microscopic
data not previously used for this question, reveals an important issue
related to residence choice and location theory and how resident workers
tend to locate with respect to network configuration in an urban context.
Keywords: Network structure, travel behavior, transport geography, commuting, circuity Regional Science and Urban Economics 39(6) 732–738 [doi]
- Liao, Chen-Fu, Henry Liu, and David Levinson (2009) Engaging
Undergraduate Students in Transportation Studies through Simulating
Transportation for Realistic Engineering Education and Training (STREET). The
practice of transportation engineering and planning has evolved substantially
over the past several decades. A new paradigm for transportation engineering
education is required to better engage students and deliver knowledge.
Simulation tools have been used by transportation professionals to
evaluate and analyze the potential impact of design or control strategy
changes. Conveying complex transportation concepts can be effectively
achieved by exploring them through simulation. Simulation is particularly
valuable in transportation education because most transportation policies
and strategies in the real world take years to implement with a prohibitively
high cost. Transportation simulation allows learners to apply different
control strategies in a risk-free environment and to expose themselves
to transportation engineering methodologies that are currently in practice.
Despite the advantages, simulation, however, has not been widely adopted
in the education of transportation engineering. Using simulation in
undergraduate transportation courses is sporadic and reported efforts
have been focused on the upper-level technical elective courses. A
suite of web-based simulation modules was developed and incorporated
in the undergraduate transportation courses at University of Minnesota.
The STREET (Simulating Transportation for Realistic Engineering Education
and Training) research project was recently awarded by NSF (National
Science Foundation) to develop web-based simulation modules to improve
instruction in transportation engineering courses and evaluate their
effectiveness. Our ultimate goal is to become the epicenter for developing
simulation-based teaching materials, an active textbook, which offers
an interactive learning environment to undergraduate students. With
the hand-on nature of simulation, we hope to improve student understanding
of critical concepts in transportation engineering and student motivation
toward transportation engineering, and improve student retention in
the field. We also would like to disseminate the results and teaching
materials to other colleges to integrate the simulation modules in
Keywords: Transportation Education and Training, Transportation Simulation, Roadway Geometry Design Transportation Research Record: Journal of the Transportation Research Board 2109 12-21. [doi]
- Tilahun, Nebiyou and David Levinson (2009) Unexpected delay and the cost of lateness on I-394 high occupancy/toll lanes. This study estimates Value of Time differences between people who arrived at their destination as planned and those that were delayed. The analysis is based on the I-394 MnPASS High Occupancy/Toll (HOT) lane project recently implemented in the Minneapolis/St. Paul region. Using a Stated Preference survey, the individuals are asked about a trip they have taken before, and asked if they would opt for the free route or pay and go on the HOT lanes. The analysis groups the travelers into subscribers and non-subscribers of the MnPASS (electronic toll collection transponder) system and further decomposes choices into categories based on trip time and experience (delayed or not). Trip times were divided into morning peak, afternoon peak, and off peak and trip experience was divided into delayed and not delayed, creating six categories. The findings suggest an increased willingness to pay among subscribers who were late to reduce travel time in the PM rush hour. As well, we find some evidence that individuals who were late during the AM peak have a lower VOT as compared to their on-time counterparts. Presented at the Third International Conference on Transport Network Reliability in Delft, Netherlands, July 2007. Published in Travel Demand Management and Road User Pricing: Success, Failure and Feasibility. Edited by Wafaa Saleh and Gerd Sammer. pp. 173-184. Ashgate Publishers
- Wu, Xinkai, David Levinson, and Henry Liu (2009) Perception
of Waiting Time at Signalized Intersections. Perceived waiting
time at signalized intersections differs from the real value, and varies
with signal design. The onerousness of delay depends on the conditions
under which it is experienced. Using weighted travel time time may
contribute to optimal signal control if its use can improve upon assuming
that all time is weighted equally by users. This research explores
the perception of waiting time at signalized intersections based on
the results of an online survey, which directly collected the perceived
waiting time and the user ratings of the signal designs of each intersection
on an arterial including 3 intersections. Statistically analyzing the
survey data suggests the perception of waiting time is a function of
the real time; and a quadratic model better can describes relationship.
The survey also indicates that there exists a tradeoff between the
total waiting time and the individual waiting time of each intersection.
It turns out that drivers prefer to split the total waiting time at
different intersections at the price of a longer total wait if the
difference of the total waiting time of two signal designs is within
30 seconds. The survey data shows that the perceived waiting time,
instead of the real waiting time, better explains how users will rate
the individual signal designs for both intersections and arterials
including multiple intersections.
Keywords: delay, perceived time, traffic signals Transportation Research Record: Journal of the Transportation Research Board 2135 pp. 52-59. [doi][bib] [poster] .
- Xie, Feng, and David Levinson (2009) Governance
Choice on a Serial Network. This paper analyzes governance choice
in a two-level federation in the provision of road infrastructure across
jurisdictions. It is demonstrated, on a serial road network shared
by two districts, that residents' preferences for public spending on
road infrastructure are differentiated by where they live and where
they travel. In consideration of differentiated travel demand and spending
preferences over space, a two-stage imperfect information game is constructed
to predict the choice of centralized or decentralized spending structure
in a representative democracy, and accordingly spending decisions at
either a central or a local level. Two models have been proposed. While
the first model considers simple Pigouvian behavior of governments,
the second explicitly models political forces at both a local and central
level. At a local level, residents in each district vote for representatives
and delegate their spending decision to elected representatives. At
a central level, spending decisions are made in a legislature of locally
elected representatives. Both models led to the conclusions that a
centralized or decentralized spending structure is chosen based on
a satisfactory comprise between benefits and costs associated with
alternative decision making processes, and that governance choice may
shift as the infrastructure improves over time.
Keywords: public choice, governance choice, transportation, infrastructure, fiscal federalism Public Choice 141: 189–212 . [doi]
- Xie, Feng and David Levinson (2009) The
Topological Evolution of Road Networks. Road networks evolve
into different topologies over time. This study explores the topological
evolution of a road network employing a simulation model that incorporates
exogenous input, degeneration, land use dynamics, travel demand dynamics,
and investment. The model is implemented and the network topologies
are visualized with a java-based simulator. Starting with idealized
networks with different geometrical features and symmetry conditions,
eight experiments incorporate specified degeneration criteria to remove
the weakest link(s) from test networks iteratively as they evolve,
resulting in various network topologies during this process. Selected
topological measures are computed throughout to track the topological
evolution of test networks.
Results demonstrate that typical topologies of road networks like rings and hub-and- spokes emerge over time even based on completely decentralized decisions of autonomous roads, and that an emergent topology of a road network has a certain insensitivity to various initial conditions. These results provide evidence for the claim that the topology of a road network is an emergent property of network evolution.
Keywords: road network, evolution, topology, degeneration, simulation Computers, Environment, and Urban Systems 33(3) 211-223 [doi]
- Xie, Feng and David Levinson (2009) Modeling the Growth of Transportation Networks: A comprehensive review. This paper reviews the progress that has been made over the last half-century in modeling and analyzing the growth of transportation networks. An overview of studies has been provided following five main streams: network growth in transport geography; traffic flow, transportation planning, and network growth; statistical analyses of network growth; economics of network growth; and network science. In recognition of the vast advances through decades in terms of exploring underlying growth mechanisms and developing effective network growth models, the authors also point out the challenges that are faced to model the complex process of transport development.Networks and Spatial Economics 9(3) 291-307. [doi]
- Xie, Feng and David Levinson (2009) Jurisdictional
Control and Network Growth. Abstract: Transport infrastructure
evolves over time in a complex process as part of a dynamic and open
system including travel demand, land use, as well as economic and political
initiatives. As transport infrastructure changes, each traveler may
adopt a new schedule, frequency, destination, mode, and/or route, and
in the long term may change the location of their activities. These
new behaviors create demand for a new round of modifications of infrastructure.
In the long run, we observe the collective change in the capacity,
service, connectivity, and connection patterns (topology) of networks.
Exploring the mechanism underlying this dynamic process can answer
questions such as how urban networks have developed into various topologies,
which networks patterns are more efficient, and whether and how transport
engineers, planners, and decision makers can guide the dynamics of
land uses and infrastructure in a desired direction. This paper examines
how a fixed set of places incrementally gets connected as transport
networks are constructed and upgraded over time. A Simulator Of Network
Incremental Connection (SONIC) models these processes and examines
how the incremental connections are actually implemented, as well as
how networks evolve differently, with regard to connectivity and efficiency,
under centralized versus decentralized jurisdictional control. The
sensitivity of emergent topologies to some model parameters is also
Keywords: Network growth, Transport economics, Incremental connection, Jurisdictional control Networks and Spatial Economics 9(3) 459-483. [doi]
- Zhang, Lei and David Levinson (2009) Economics
of Road Network Ownership. Abstract: This paper explores the economic
impact of alternative ownership structures on transportation system performance,
social welfare, and regulatory needs. Road pricing, investment, and ownership
decisions are jointly considered in an agent-based evolutionary model applicable
to large networks. Results suggest that a centralized public regime with
average-cost pricing is far from socially optimal with even moderate demand
growth. When properly regulated, a completely privatized transportation network
could achieve net social benefits close to the theoretical optimum and distribute
a high percentage of welfare gains to travelers. But an unregulated private
road economy would suffer from higher-than-optimal tolls and overinvestment.
Keywords: Network economics, Modeling network dynamics, Road pricing, Transportation financing, Privatization. International Journal of Sustainable Transportation Sept. 2009 3(5) pp. 339-359. [presentation] [doi]
- Zhang, Lei, Feng Xie, David M. Levinson (2009) Illusion of Motion: Variation
in Travel Time under Different Driving Conditions. This
paper explores drivers' subjective value of time under moving and stopped
freeway travel conditions using a stated preference survey. Unlike
previous studies that assume a constant value of time, this research
relates perceived satisfaction of a freeway trip to its quality indicators.
Sixty-nine subjects in the Twin Cities are asked in the survey to rank
sixteen driving scenarios in four condition sets with different durations
of ramp wait and freeway travel. Several utility functions are specified
where the weight of ramp delay is a function of the length of the delay
itself and subject specific variables, and the resulting choice models
estimated using rank-ordered logit and binary logit techniques. Results
suggest that drivers perceive ramp wait as more onerous than freeway
travel. Drivers also weight each minute of ramp wait more heavily as
the length of the delay gets longer. Although the subjects show some
tolerance to the first several minutes of ramp delay (less than 5 minutes),
they perceive long delays as much as twelve times more onerous than
time in motion. The derived weighting function for ramp wait can improve
the design of freeway traffic control strategies that trade-off freeway
delay with ramp wait. The findings also enable a more utility-based
approach for freeway operations than the current method which has the
engineering efficiency objective of minimizing total system delay or
maximizing throughput. Minimizing total perceived travel time is probably
more appropriate than minimizing total absolute travel time which does
not take into account driver acceptance. The weighting function can
also be easily transformed into a value of time function for project
Keywords: Value of time, value of travel time, Time perception, Driver acceptance, Freeway congestion, Ramp meter (05-0868) Transportation Research Record: Journal of the Transportation Research Board 2135 pp 34-42. [doi]
- Iacono, Michael, David Levinson and Ahmed El-Geneidy (2008) Models of Transportation and Land Use Change: A Guide to the Territory. Modern urban regions are highly complex entities. Despite the difficulty of modeling every relevant aspect of an urban region, researchers have produced a rich variety models dealing with inter-related processes of urban change. The most popular types of models have been those dealing with the relationship between transportation network growth and changes in land use and the location of economic activity, embodied in the concept of accessibility. This paper reviews some of the more common frameworks for modeling transportation and land use change, illustrating each with some examples of operational models that have been applied to real-world settings. Journal of Planning Literature 2008 22: 323-340.
- King, David, Kevin Krizek, and David Levinson (2008) Designing
and Assessing a Teaching Laboratory for an Integrated Land Use and
Transportation Course. The intersection of land use and transportation
policy is becoming an increasingly important focus for all urban planners.
This focus, however, challenges the academic community to design effective
courses that teach the concepts and professional skills required for
professional experience. Integrated land use and transportation courses
should engage students to develop interdisciplinary skills while becoming
familiar with, for example, travel behavior and zoning policies. Laboratory
courses (or segments of courses) as part of graduate curricula provide
platforms to further emphasize skills. A common pedagogy problem is
devising laboratory assignments that are integrative, cumulative, practical,
and interesting for students. Furthermore, laboratory projects should
introduce students to real-world problems and techniques while exploring
broad planning themes. This paper presents uses four years of laboratory
segments from a land use-transportation course (LUTC) at the University
of Minnesota to evaluate the needs and results of practitioner-oriented
land use and transportation planning education. The laboratory used
group projects where students proposed integrated developments using
air rights above existing (and sunken) urban freeways in the Twin Cities.
The projects provided a practitioner-oriented project through a collaborative
and reflexive learning process. This article describes the completed
projects, as well as the technical skills, integrated approach and
visionary planning necessary for successful execution. The students
addressed complicated problems associated with large-scale development
by researching neighborhood demographics, characteristics, and pertinent
regulations. They used their research to analyze traffic impacts, propose
zoning regulations, and outline costs and benefits from their proposal
using Geographic Information Systems (GIS), statistical analyses, assessor
data and traffic engineering manuals. Using the completed student projects
and comparisons with other land use-transportation course and laboratory
projects the authors demonstrate how these laboratory components serve
multiple pedagogy goals.
Keywords: Air Rights, Transportation-Land Use Planning, Education Transportation Research Record: Journal of the Transportation Research Board #2046 pp 85-93 [doi]
- Levinson, David (2008) Density
and Dispersion: The Co-Development of Land use and Rail in London. This
paper examines the changes that occurred in the rail network and density
of population in London during the nineteenth and twentieth centuries.
It aims to disentangle the ”chicken and egg” problem of which came
first, network or land development, through a set of statistical analyses
using clearly distinguishing events by order. Using a panel of data
representing the 33 boroughs of London over each decade from 1871 to
2001, the research finds that there is a positive feedback effect between
population density and network density. Additional rail stations (either
underground or surface) are positive factors leading to subsequent
increases in population in the suburbs of London, while additional
population density is a subsequent factor in deploying more rail. These
effects differ in central London, where the additional accessibility
produced by rail led to commercial development and led to a depopulation.
There are also few differences in the effects associated with surface
rail stations and underground stations, as the underground was able
to get into central London in a way that surface rail could not. However
the two networks were weak (and statistically insignificant) substitutes
for each other in the suburbs, but the density of surface rail stations
was a complement to the Underground in the center, though not vice
Keywords: Transport, land use, London Underground, London railways, network growth, induced demand, induced supply Journal of Economic Geography 8(1) 55-57.
JEG: [Abstract], [Full text], [PDF] [doi]
- Levinson, David (2008) The
Orderliness Hypothesis: Does Population Density Explain the Sequence
of Rail Station Opening in London? Network growth is a complex
phenomenon; some researchers have suggested that it occurs in an orderly
or rational way, based on the size of places that are connected. This
paper examines the order in which stations were added to the London
surface rail and Underground rail networks in the 19th and 20th centuries,
testing to what extent that order was correlated with population density.
While population density is an important factor in explaining order,
this research shows that other factors are at work. The network itself
helps to reshape land uses, and a network that may have been well ordered
at one time, may drift away from order as activities relocate.
Keywords: Transport and land use, London Underground, network growth, railways Journal of Transport History 29(1) March 2008 pp.98-114.[download]
- Levinson, David and Andrew Odlyzko (2008) Too Expensive to Meter: The influence of transaction costs in transportation and communication. Technology appears to be making fine-scale charging (as in tolls on roads that depend on time of day or even on current and anticipated levels of congestion) increasingly feasible. And such charging appears to be increasingly desirable, as traffic on roads continues to grow, and costs and public opposition limit new construction. Similar incentives towards fine-scale charging also appear to be operating in communications and other areas, such as electricity usage. Standard economic theory supports such measures, and technology is being developed and deployed to implement them. But their spread is not very rapid, and prospects for the future are uncertain. This paper presents a collection of sketches, some from ancient history, some from current developments, that illustrate the costs that charging imposes. Some of those costs are explicit (in terms of the monetary costs to users, and the costs of implementing the charging mechanisms). Others are implicit, such as the time or the mental processing costs of users. These argue that the case for fine-scale charging is not unambiguous, and that in many cases may be inappropriate. Philosophical Transactions of the Royal Society A: Mathematical Physical and Engineering Sciences 366(1872) pp 2033–2046 [doi] [poster] [presentation]
- Xie, Feng and David Levinson (2008) The
Use of Road Infrastructure Data for Urban Transportation Planning:
Issues and Opportunities. In order to maintain and improve road
infrastructure in their respective jurisdictions, the state (the Minnesota
DOT), region (the Metropolitan Council), and seven counties in the
Twin Cities Metropolitan area develop their respective decision making
(investment) processes in which federal or local funding are periodically
allocated to road projects, prioritized according to their funding
needs based on measured road infrastructure conditions such as pavement
quality, level of service, and safety. Including such an investment
process in urban transportation planning enables forecasting changes
to road infrastructure in the future. Periodic road infrastructure
reporting provides standards the jurisdictions maintain, as well as
the measures they adopt for the management of road conditions. These
measures, developed and maintained by engineers, however, are inconsistent
with transportation planning models, causing difficulties in fully
using infrastructure reports in planning practice. This paper addresses
the issues we encountered with regard to the use of road infrastructure
reports in planning practice and identifies the opportunity to improve
the inter-operability and integration of infrastructure reporting with
urban transportation planning.
Keywords: road conditions, infrastructure, urban transportation, urban planning. Published in Infrastructure Reporting and Asset Management Edited by Adjo Amekudzi and Sue McNeil. pp- 93-98. Publisher: American Society of Civil Engineers, Reston, Virginia..
- Xie, Feng and David Levinson (2008) The
Weakest Link: A Model of the Decline of Surface Transportation Networks. Abstract:
This study explores the economic mechanisms behind the decline of a
surface transportation network, based on the assumption that the decline
phase is a spontaneous process driven by decentralized decisions of
individual travelers and privatized links. A simulation model is developed
with a degeneration process by which the weakest link is removed iteratively
from the network. Experiments reveal how the economic efficiency of
a network evolves during the degeneration process and suggest an 'optimal'
degenerated network could be derived during the decline phase in terms
of maximizing total social welfare.
Keywords: decline, transportation network, degeneration, welfare, accessibility Transportation Research part E 44 100-113. [doi] [bib] [poster]
- Zhang, Lei and David Levinson (2008) Determinants
of Route Choice and the Value of Traveler Information: A Field Experiment. A
major strategy of federal ITS initiatives and state departments of
transportation is to provide traveler information to motorists through
various means, including variable message signs, the internet, telephone
services like 511, in-vehicle guidance systems, and TV and radio reports.
This is relatively uncontroversial, but its effectiveness is unknown.
Drivers receive value from traveler information in several ways, including
the ability to save time, but perhaps more importantly, other personal,
social, safety, or psychological impacts from certainty. This information
can be economically valued. The benefits of reduction in driver uncertainty
when information is provided at the beginning of the trip by various
means is the main variable we aim to measure in this research, in which
we assess user preferences for routes as a function of the presence
and accuracy of information, while controlling for other trip and route
attributes, such as trip purpose, travel time, distance, number of
stops, delay, esthetics, level of commercial development, and individual
characteristics. Data is collected in a field experiment in which more
than 100 drivers, given real-time travel time information with varying
degrees of accuracy, drove four of five alternative routes between
a pre-selected OD pair in the Twin Cities metro area. Ordinary regression,
multinomial, and rank-ordered logit models produce estimates of the
value of information with some variation. In general, results show
that travelers are willing to pay up to $1 per trip for pre-trip travel
time information. The value of information is higher for commute and
event trips and when congestion on the usual route is heavier. The
accuracy of the traveler information is also a crucial factor. In fact,
there do not seem be incentives for travelers to use traveler information
at all unless they perceive it to be accurate. Finally, most travelers
(70%) prefer that such information should be provided for free by the
public sector, while some (19%) believe that it is better for the private
sector to provide such service at a charge. Over 35% of subjects are
willing to pay for OD-customized pre-trip travel time information.
Keywords: Value of Information, Advanced Traveler Information System (ATIS), Real-Time Traffic Operations, Travel Behavior, Spatial behavior, Wayfinding Behavior, Route Choice. Transportation Research Record: Journal of the Transportation Research Board 2086:81-92 [doi]
- Zhang, Lei, and David M. Levinson (2008) Investing
for Reliability and Security in Transportation Networks. Alternative
transportation investment policies can lead to very different network
forms in the future. The desirability of a transportation network should
be assessed not only by its economic efficiency but also reliability,
because the cost of incidental capacity loss in a road network can
be massive. This research concerns how investment rules shape the hierarchical
structure of roads, and affects network fragility with regard to natural
disasters, congestion, and accidents and vulnerability to targeted
attacks. A microscopic network growth model predicts the equilibrium
road networks under two alternative policy scenarios: investment based
on benefit cost analysis or bottleneck removal. A set of Monte-Carlo
simulation runs, in which a certain percentage of links are removed
according to the type of network degradation analyzed, are carried
out to evaluate the equilibrium road networks. It is found that hierarchy
exists in road networks for reasons such as economic efficiency, but
an overly hierarchical structure has serious reliability problems.
Throughout the equilibrating or evolution process, the studied grid
network under benefit cost analysis has better efficiency performance,
as well as error and attack tolerance. The policy implication from
these findings is that benefit-cost analysis should be preferred to
myopic bottleneck-removal type of investment rules, no matter how the
planning horizon is specified.
Keywords: Transportation network dynamics, road growth model, reliability, vulnerability, fragility, road investment and financing policy (05-0897) Transportation Research Record: Journal of the Transportation Research Board #2041 pp.1-10 [doi]
- Zhang, Lei, David Levinson, and Shanjiang Zhu (2008) Agent-Based Model of Price Competition and Product Differentiation on Congested Networks. Abstract: Using consistent agent-based techniques, this research models the decision-making processes of users and infrastructure owner/operators to explore the welfare consequence of price competition, capacity choice, and product differentiation on congested transportation networks. Component models include: (1) An agent-based travel demand model wherein each traveler has learning capabilities and unique characteristics (e.g. value of time); (2) Econometric facility provision cost models; and (3) Representations of road authorities making pricing and capacity decisions. Different from small-network equilibrium models in prior literature, this agent-based model is applicable to pricing and investment analyses on large complex networks. The subsequent economic analysis focuses on the source, evolution, measurement, and impact of product differentiation with heterogeneous users on a mixed ownership network (with tolled and untolled roads). Two types of product differentiation in the presence of toll roads, path differentiation and space differentiation, are defined and measured for a base case and several variants with different types of price and capacity competition and with various degrees of user heterogeneity. The findings favor a fixed-rate road pricing policy compared to complete pricing freedom on toll roads. It is also shown that the relationship between net social benefit and user heterogeneity is not monotonic on a complex network with toll roads. Journal of Transport Economics and Policy Sept. 2008 42(3) pp. 435-461. [download]
- El-Geneidy, Ahmed and David Levinson (2007) Mapping Accessibility Over Time. Abstract: The concept of 'accessibility' has been coin in the transportation planning field for more than 40 years. Improving accessibility is a common element in the goals section in almost all transportation plans in the US. In this study we compare the changes in levels of accessibility over time in the Minneapolis - St. Paul region using two different modes (auto and transit). The importance of accessibility as a measure of land use and transportation planning performance in the region is revealed by comparing it over time. The longitudinal analysis being conducted shows improvements in most areas in the studied region in terms of the level of accessibility by automobile, and a drop in accessibility by transit over the period 1990 to 2000. The findings are compared to the levels of congestion in the region between the same time periods. This comparison shows the difference between the two measures and strengthens the importance of accessibility measures as a tool for monitoring and evaluating regional land use and transportation planning performance. Journal of Maps v2007, 76-87. [bib]
- Levinson, David, and Wei Chen (2007) Area
Based Models of New Highway Route Growth. Abstract: Empirical
data and statistical models are used to answer the question of where
new highway routes are most likely to be located. High-quality land-use,
population distribution and highway network GIS data for the Twin Cities
Metropolitan Area from 1958 to 1990 are developed for this study. The
highway system is classified into three levels, Interstate highways,
divided highways, and secondary highways. Binary logit models estimate
the new route growth probability of divided highways and secondary
highways. Interstates, however,are not modeled here and are used as
a predictor in modeling the growth of divided highways and secondary
highways. The results show that the area's land-use attributes and
population density level do have significant relationship with the
area's likelihood of adding new highway routes.
Keywords: network growth, hierarchy of roads, land-use, population, GIS. ASCE Journal of Urban Planning and Development 133(4) 250-254. [bib]
- Levinson, David, Reinaldo C. Garcia, and Kathy Carlson (2007) A
Framework for Assessing Public Private Partnerships. This paper
examines in detail Public Private Partnerships (PPPs), discussing their
main objectives, implementations and challenges. The possible joint
venture between the government and private companies when establishing
a PPP is addressed, and an analytical approach to evaluate a PPP measure
of success (M) is proposed. Applications of PPP are described, giving
special attention to American and European experiences. It concludes
by examining future extensions of the analytical Measure of Success
of a PPP and what lies ahead for future PPP implementations.
Keywords: Public Private Partnership; Tagus River Bridge, Alameda Corridor; Dulles Gateway; European Experience in Institutions and Regulatory Reform in Transport (ed. Piet Rietveld and Roger Stough) Edward Elgar Publishers .
- Levinson, David, Feng Xie, and Shanjiang Zhu (2007).
The Co-Evolution of Land Use and Road Networks.
This paper explores the co-evolution of land use and transportation, which is a poorly understood field despite progress in studying each separately. Our study models the co-evolution of land use and transportation network as a bottom-up process by which re-location of activities and expansion of roads are driven by interdependent decisions of individual businesses, workers, and road owners according to simple decision rules. The model was kept simple to best illustrate collective spatial patterns of land use distribution without conflating factors. The sensitivity of these patterns is also discussed. A Simulator of Integrated Growth of Networks And Land-use (SIGNAL) is developed to implement these decentralized decision making processes, in which the Gini index and equivalent radius were computed to describe and track down the spatial patterns of space and network. Simulation experiments were conducted to explore the evolution of land use patterns in the context of the coevolution of land use and road networks. Experimental results demonstrate that initially flat land uses become more concentrated while initially concentrated land uses become less so, and they tend to converge on the same hierarchical distribution, suggesting that a stable hierarchical distribution of land use may emerge from different initial conditions. Experiments also reveal that the concentration of land use is reinforced by the differentiation of roads.
Keywords: Network growth,land use, road network, evolution, self-organization Presented at the Seventeenth International Symposium on Transportation and Traffic Theory at Imperial College, London, July 2007. Published in Transportation and Traffic Theory 2007 (ed. Richard E. Allsop, Michael G. H. Bell, and Benjamin Heydecker) Emerald Group Pub Ltd. pp. 839-859. (Earlier version presented at the North American Regional Science Conference, Toronto, Ontario, November 2006)
- Tilahun, Nebiyou Yonas, David M. Levinson, and Kevin J. Krizek (2007) Trails, Lanes, or Traffic: Value of Different Bicycle Facilities Using Adaptive Stated-Preference Survey. Abstract: This study evaluates individual preferences for five different cycling environments by trading off a higher travel time as a cost incurred when choosing a better facility while letting the user have the option of selecting a less attractive facility at a lower travel time. The tradeoff of travel time to amenities of a particular facility informs our understanding of the value attached to different attributes such as bike-lanes, off-road trails, or side-street parking. The facilities considered here are off-road facilities, in-traffic facilities with bike-lane and no side street parking, in-traffic facilities with a bike-lane and side street parking, in-traffic facilities with no bike-lane and no side street parking and in-traffic facilities with no bike-lane but with parking on the side. We find that respondents are willing to travel up to twenty minutes more to switch from an unmarked on-road facility with side parking to an off-road bicycle trail, with smaller changes associated with less dramatic improvements.) Transportation Research: A Policy and Practice 41 (4) 287-301 [doi] [bib] [poster]
- Xie, Feng and David Levinson (2007) Measuring
the Structure of Road Networks. Abstract: Spatial networks display
both topologic and geometric variations in their structure. This study
investigates the measurement of road network structure. Existing measures
of heterogeneity, connectivity, accessibility, and interconnectivity
are reviewed and three supplemental measures are proposed, including
measures of entropy, connection patterns, and continuity. Proposed
measures were applied to 16 test networks, which were derived from
4 idealized base networks: 90-degree, 45-degree, 30-degree, and completely
connected. The results show that the differentiated structures of road
networks can be evaluated by the measure of entropy; predefined connection
patterns of arterial roads can be identified and quantified by the
measures of ringness, webness, beltness, circuitness, and treeness.
A measure of continuity evaluates the quality of a network from the
perspective of travelers. Proposed measures could be used to describe
the structural attributes of complicated road networks quantitatively,
to compare different network structures, and to explore the structural
evolution of networks in the spatial and temporal context. These measures
can find their applications in urban planning and transportation practice.
Keywords: Networks, Transportation, Structure, Entropy, Pattern, Continuity Geographical Analysis 39(3) pp.336-356 [bib] [doi]
- Zhang, Lei and David Levinson (2007) The Economics of Transportation Network Growth. A number of factors influence the efficiency, productivity, and welfare of a transportation network. Travel demand, user costs, and facility supply costs equilibrate on various time scales under a set of pricing (taxes and tolls), investment and ownership policies. Two types of equilibria exist in a transportation network, short-run traffic equilibrium and long-run supply-demand equilibrium. The phenomenon of traffic equilibrium is explored with a fixed transportation network where the capacity of links is given. Even though investment- and ownership-related policies are not of major concern for studies on traffic equilibrium, it is still a complex problem due to network congestion effects, variations of pricing rules, and multidimensionality of user choices. In order to understand the long-run supply-demand equilibrium in a transportation network, one has to consider all above-mentioned factors in a coherent analytical framework. We refer to this research problem as the transportation network growth problem, because the network evolves and link capacity is not fixed in the long run. Most previous studies have considered network pricing, investment, and ownership structures separately, which are reviewed. The paper considers choices of prices, capacity, and ownership simultaneously on small parallel, serial, and parallel-serial networks, and develops an analytical network model. We discuss properties of long-run network equilibria with different network layouts and ownership regimes, and the implications on network efficiency. in Essays on Transportation Economics. (ed. Pablo Coto Millán & Vicente Inglada) Springer. Contributions to Economics
- Chen, Wenling and David Levinson (2006) Effectiveness
of Learning Transportation Network Growth Through Simulation. Abstract:
Computer simulation plays an increasingly important role in engineering
education as a tool for enhancing classroom learning. This research
investigates the efficacy of using simulation in teaching the topic
of transportation network growth through an experiment conducted at
the Civil Engineering Department of the University of Minnesota. In
the experiment, a network growth simulator program (SONG) was incorporated
into a senior/graduate class in transportation system analysis. Results
of the experiment show that the use of SONG effectively enhanced students'
learning in terms of helping students develop in-depth understanding
about the development process of network patterns, and helped them
develop some aspects of judgment, problem-solving, and decision-making
skills. However the use of SONG may have been more effective had some
other barriers to learning been overcome.
Keywords: Simulation, Engineering Education, and Transportation Network Growth ASCE Journal of Professional Issues in Engineering Education and PracticeVol. 132, No. 1, January 1, 2006. [doi] [bib] [poster]
- Levinson, David (2006) The Political Economy of Private Roads. This paper first briefly reviews the history of private roads. Then the functional and economic classification of roadways is presented. Three different classes of roads (local, linking, and limited access) need to be treated in very different ways. The ideology of private roads is then presented. The political factors constraining this ideology from taking root are then presented. Distributional effects associated with privatization are described, and means for using the proceeds from the sale of roads to compensate losers are presented. Prospects for the future of private roads are discussed in the conclusions.Chapter 4 (pp. 79-96) in Street Smart : Competition, Entrepreneurship, and the Future of Roads (ed. Gabriel Roth), Transaction Publishers of Rutgers University
- Levinson, David, Kathleen Harder, John Bloomfield, Kathy Carlson (2006) Waiting
Tolerance: Ramp Delay vs. Freeway Congestion. Abstract: Waiting
tolerance at ramp meters and travel time on the freewaywere measured
using a computer administered stated preference (CASP) survey and a
virtual experience stated preference (VESP) methodemploying a driving
simulator.The selections varied in the number of minutes waiting at
a ramp meter with vehicle speed once on the freeway. The subjects ranked
the selections in order of preference. The results were statistically
analyzed using a binary logit model controlling for demographics, socioeconomic
characteristics, daily travel time, and personality scores.The results
by the CASP method displayed a preference for freeway congestion to
ramp delay, but opposite results were obtained by the VESP method.
A number of reasons are posited to explain the difference, but the
results indicate that method of stated preference data collection can
significantly affect conclusions drawn.
Keywords: Ramp meters; Personality; Stated preference; Driving simulator; Travel time Transportation Research part F: Traffic Psychology and Behaviour Volume 9, Issue 1 , January 2006, Pages 1-13. [doi] [bib]
- Levinson, David and Bhanu Yerra (2006) Self
Organization of Surface Transportation Networks. Abstract: This
research investigates the self-organization of surface transportation
networks. Using a travel demand model coupled with revenue, cost, and
investment models, experiments are run under a variety of parameters
on a grid network. It is found that roads, contiguous sections of multiple
links operating with similar characteristics, and hierarchies of roads
emerge under a broad range of assumptions from networks with neither
defined roads nor clearly organized hierarchies. The factors which
drive this are the (dis)economies of scale, the presence of boundaries,
and any initial asymmetry in the network. This research thus finds
that roads and hierarchies, which are often thought to be the product
of conscious design, can also arise without such intention.
Keywords: Self-organization, network growth, network evolution, transportation planning Transportation Science Vol. 40 No. 2 May 2006 pp. 179-188 [doi] [bib]
- Levinson, David and Lei Zhang (2006) Ramp
Meters on Trial: Evidence from the Twin Cities Metering Holiday. Abstract:
Ramp meters in the Twin Cities have been the subject of a recent test
of their effectiveness, involving turning them off for 8 weeks. This
paper analyzes the resultswith and without ramp metering for several
representative freeways during the afternoon peak period. Seven performance
measures: mobility, equity, productivity, consumers' surplus, accessibility,
travel time variation and travel demand responses are compared. It
is found that ramp meters are particularly helpful for long trips relative
to short trips.Ramp metering, while generally beneficial to freeway
segments, may not improve trip travel times (including ramp delays).
The reduction in travel time variation comprisesanother benefit from
ramp meters. Non-work trips and work trips respond differently to ramp
meters. The results are mixed, suggesting a more refined ramp control
algorithm,which explicitly considers ramp delay, is in order.
Keywords: Ramp Meters, Evaluation, Equity, Mobility, Accessibility, Productivity, Consumers' Surplus, Travel Time Variation, Travel Demand Transportation Research: A Policy and Practice Volume 40, Issue 10 , December 2006, Pages 810-828. [doi] [bib]
- Levinson, D. and Ewa Zofka (2006) The Metropolitan Travel Survey Archive: A Case Study in Archiving. This paper summarizes research on standards for archiving travel survey data. It then describes some of the efforts at organizing data and developing metadata. The development of metadata standards used for documenting datasets using DDI (Data Documentation Initiative) for DTD (Document Type Definitions) is described. A case, applying these approaches to a US Metropolitan Travel Survey Archive is presented. The Metropolitan Travel Survey Archive, housed at the University of Minnesota, now contains over 60 surveys from almost 30 metropolitan areas. The paper concludes with some recommendations for archiving data. in Travel Survey Methods . Presented at 7th International Conference on Travel Survey Methods. Los Sueños, Costa Rica. August 1-6 2004.
- Montes de Oca, Norah and David Levinson (2006) Network Expansion Decision-making in the Twin Cities. Abstract: This paper presents a qualitative analysis of the decision-rules used by jurisdictions in Minnesota's Twin Cities metropolitan area. Interviews were conducted with staff at the city, county, metropolitan, and state levels to determine how decisions about road investment, expansion and new construction were made. Flowcharts were developed to provide a more systematic way of presenting that information. Most jurisdictions do not have extensive public participation processes, though several, notably the Metropolitan Council, Hennepin and Ramsey Counties and the City of Minneapolis do. Jurisdictions with public participation have the most formal and extensive documentation of their investment decision process. The decision factors vary by jurisdiction, though safety, capacity, and pavement quality were important throughout. Journal of the Transportation Research Board: Transportation Research Record#1981 (Planning and Analysis 2006) pp 1-11 [ISBN: 0309099919] [bib]
- Smalkoski, B., Ning Li, and David Levinson (2006) Economic Effects of Lifting the Spring Load Restriction Policy in Minnesota. Abstract: Spring load restrictions (SLR) regulate the weight per axle carried by heavy trucks during the spring thaw period. This policy aims to reduce pavement damage caused by heavy vehicles and extend the useful life of roads, but it also imposes costs on the trucking industry due to detouring or increased number of truckloads. Although the policies have been implemented for many years, their resulting economic effect has been unclear. The Minnesota Local Road Research Board (LRRB) and the Minnesota Department of Transportation (Mn/DOT) sponsored a cost/benefit study of spring load restrictions in Minnesota. The study, based on the results of surveys of industry costs, a pavement performance model, and a freight demand model, concludes that the benefits of lifting the existing SLR policy outweigh the additional costs. Roadways operating at 5-tons require additional study; however, current analysis warrants repealing SLR and keeping roadways operating year-round at 9-tons. The cost of additional damage should be recovered from those who benefit from the change in policy. Journal of the Transportation Research Forum 45(2) pp. 45-56. [bib]
- Zou, Xi and David Levinson (2006) Modeling Pipeline Driving Behaviors: A Hidden Markov Model Approach. Abstract: Driving behaviors at intersection are complex because drivers have to perceive more traffic events than normal road driving and thus are exposed to more errors with safety consequences. Drivers make real-time responsesin a stochastic manner. This paper presents our study using Hidden Markov Models (HMM) to model driving behaviors at intersections. Observed vehicle movement data are used to build up the model. A single HMM is used to cluster the vehicle movements when they are close to intersection. The re-estimated clustered HMMs provide better prediction of the vehicle movements compared to traditional car-following models. Only through vehicles on major roads are considered in this paper. Journal of the Transportation Research Board: Transportation Research Record #1980 (Driver Behavior, Older Drivers, Simulation, User Information Systems, and Visualization) pp. 16-23. [ISBN: 0309099900] [bib]
- Zou, Xi and David Levinson (2006) A
Multi-Agent Congestion and Pricing Model. Abstract: A multi-agent
model of travelers competing to utilize a roadway in time and space
is presented in this paper to illustrate the effect of congestion and
pricing on traveler behaviors and network equilibrium. To realize the
spillover effect among travelers, N-player games are constructed in
which the strategy set include (N+1) strategies. We solve the N-player
game (for N ≤ 7) and find Nash equilibria if they exist. This model
is compared to the bottleneck model. The results of numerical simulation
show that the two models yield identical results in terms of lowest
total costs and marginal costs when a social optimum exists.
Keywords: Agent-based Model, Game Theory, Congestion, Queueing, Traffic Flow, Congestion Pricing, Road Pricing, Value Pricing Transportmetrica Vol.2, No.3, 2006 pp.237-249. [doi] [bib] [poster]
- Krizek, K. and David Levinson (2005) Teaching Integrated Land Use-Transportation Planning: Topics, Readings, and Strategies. Abstract: Planning pedagogy is increasingly focused on ways to teach interdisciplinary topics in an integrated and synergistic manner. The intersection of land use and transportation represent two topics that, in recent years, have risen front and center for the planning profession as a whole as well as for individual program specialization areas. This article focuses on the manner in which planning programs and in particular, specific courses, address land use and transportation planning. After describing the context in which such courses exist (e.g., program specializations, faculty size), the bulk of this analysis centers on analyzing syllabi from 15 courses in North American planning programs that squarely address integrated land use-transportation planning. The syllabi are analyzed in two respects. The first examines the list of topics covered within each course. The nature of primary, secondary, and peripheral topics (as assessed by the frequency in which they appear in the syllabi) are discussed. Second, the analysis uncovers the frequency in which specific readings are used in each course (articles, book chapters, books). Special attention is devoted to discussing the substance (e.g., what topics), origin (e.g., journal name), and/or the availability of key readings. The article closes by discussing the detailed nature of a sample land use-transportation course from the Urban and Regional Planning Program at the University of Minnesota in which there is a lecture and laboratory component. Journal of Planning Education and Research 24(3) pp. 304-316. [doi][bib]
- Levinson, D (2005) Paying
for the Fixed Costs of Roads. Abstract: This paper explores
alternative financing mechanisms to pay for the fixed costs of roads,
particularly in cases without rising marginal costs. Mechanisms considered
include tolls, gas taxes, and developer payments. The problems with
each are discussed. An example looking at problems of temporal and
spatial free-riding is presented.
Keywords: Transportation financing, economics, toll roads, impact fees Journal of Transport Economics and Policy, Volume 39, Part 3, September 2005, pp. 279-294. [JSTOR] [bib]
- Levinson, David (2005) The Evolution of Transport Networks. Between 1900 and 2000, the length of paved roads in the United States increased from 240 km to 6,400,000 km (Peat 2002, BTS 2002) with virtually 100% of the U.S. population having almost immediate access to paved roadways. Similarly, in 1830 there were 37 km of railroad in the United States, but by 1920 total track mileage had increased more than ten-thousand times to 416,000 km miles, however since then, rail track mileage has shrunk to about 272,000 km (Garrison 1996, BTS 2002). The growth (and decline) of transport networks obviously affects the social and economic activities that a region can support; yet the dynamics of how such growth occurs is one of the least understood areas in transport, geography, and regional science. This is revealed time and again in the long-range planning efforts of metropolitan planning organizations (MPOs), where transport network changes are treated exclusively as the result of top-down decision-making. Changes to the transport network are rather the result of numerous small decisions (and some large ones) by property owners, firms, developers, towns, cities, counties, state department of transport districts, MPOs, and states in response to market conditions and policy initiatives. Understanding how markets and policies translate into facilities on the ground is essential for scientific understanding and improving forecasting, planning, policy-making, and evaluation. , Chapter 11 (pp 175-188) in Handbook of Transport Strategy, Policy and Institutions Volume 6 (Handbooks in Transport), (ed. Kenneth Button and David Hensher) Elsevier, Oxford.
- Levinson, David and Wei Chen (2005) Paving
New Ground. This paper explores the inter-connectedness and co-evolution
of transportation networks and land use through the application of
a Markov Chain model. This model investigates how individual cells,
with both land use and transportation network attributes, change over
time. Cells with more transportation network available are more likely
to develop, and cells that are developed are more likely to attract
additional highway investment.
Keywords: Transportation Network Growth, Transportation-Land Use Interaction, Markov Chain , in Access to Destinations (ed. David Levinson and Kevin Krizek) Elsevier Publishers. [poster]
- Levinson, David, Kevin Krizek and David Gillen(2005) Machine for Access., in Access to Destinations (ed. David Levinson and Kevin Krizek) Elsevier Publishers.
- Zou, Xi and David Levinson (2005) Financing and Deploying Automated Freight Systems. New technologies are bringing Automated Freight Systems (AFS), which aim to reduce congestion, mitigate environmental impacts and enhance public safety, to fruition. The financing and deployment issues of AFS differ from other Intelligent Transport System applications. This chapter briefly introduces major concepts of AFS. The financing strategies for these concepts are discussed, in which the government subsidies play an important role through the use of public-private partnership. Economies of scale and externalities of the current and new systems are discussed. In the discussion of the deployment of AFS, it is suggested that deployment schemes are highly correlated with financing strategies. inThe Future of Automated Freight Transport: Concepts, Design and Implementation. (ed. Rob Konings, Peter Nijkamp, Hugo Peimus) Edward Elgar pp. 227-242.
- Levinson, David (2005) Micro-foundations
of Congestion and Pricing: A Game Theory Perspective. Abstract:
This paper develops congestion theory and congestion pricing theory
from its microfoundations, the interaction of two or more vehicles.
Using game theory, with a two-player game it is shown that the emergence
of congestion depends on the players-relative valuations of early arrival,
late arrival, and journey delay. Congestion pricing can be used as
a cooperation mechanism to minimize total costs (if returned to the
players). The analysis is then extended to the case of the three-player
game, which illustrates congestion as a negative externality imposed
on players who do not themselves contribute to it.
Keywords: Game Theory, Congestion, Queueing, Traffic Flow, Congestion Pricing,Road Pricing, Value Pricing Transportation Research part A Volume 39, Issues 7-9 , August-November 2005, Pages 691-704. [doi][bib]
- Levinson, D, and Yao Wu (2005) The Rational Locator Re-examined. Abstract: The Rational Locator Hypothesis posits that individuals can, if they choose, maintainapproximately steady journey-to-work travel times by adjusting their home and workplace. This hypothesis was coupled with the observation of long-term stability indrive alone journey-to-work times in metropolitan Washington (those times were unchanged from 1957 through 1968 to 1988). Despite the increase of averagecommuting distance and congestion, trip duration remained constant or even declined when controlling for travel purpose and travel mode because of shifting a share of traffic from slow urban routes to faster suburban routes. This observation has significance, as it is important to know for travel demand analysis if there is an underlying budget, or even a regularity, as this helps us determine whether our forecasts are reasonable. To retest the underlying rationale for the hypothesis: that travel times are stable, both intra-metropolitan and inter-metropolitan comparisons of travel times are made. The intra-metropolitan analysis compared Washington DC data from 1968, 1988, and 1994, and Twin Cities data from 1990 and 2000. The results depend upon geography. For the larger Washington DC region, keeping the same geography shows little change in commute times, but using the larger 1994 area suggests an increase in commute times.However, the Twin Cities, starting from a much shorter commute time, shows a marked increase over the decade, using either the smaller or the larger geography. To explain the differences between the two areas, an inter-metropolitan analysis conducts a series of regressions on mean metropolitan travel time for the 65 largest metropolitan areas in theUnited States. The average commute time varies (positively) in these cities as a function of congestion and population density-both significant at the 99% confidence interval.Geographical area, population, and income were also significant at the 90% confidence interval. Despite the continuing observation of stability in drive alone commuting timesin metropolitan Washington, we reject the theory of personal commuting budgets, as we find that not only are commuting times not generally stable over time at the intra-metropolitan area, but that commuting time clearly depends on metropolitan spatial structure. Transportation 32 187-202. [doi][bib] [presentation]
- Smalkoski, Brian, and David Levinson (2005) Value of Time for Commercial Vehicle Operators. Abstract: The spring load restriction policy of Minnesota has been in effect for over 50 years with little consideration given to the cost that it imposes on the freight industry. A cost-benefit study was recently commissioned to examine the policy. The cost-benefit analysis required a precise estimate of the value of time for commercial vehicle operators in Minnesota. An estimate was not available from previous studies, or from previous data. The necessary revealed preference (RP) information does not exist, and relevance of previous studies was questioned based on the differences in geographic location and the age of data used to construct the estimates. A sample was constructed from several trucking industry sources to conduct a survey. Interviews were conducted using an adaptive stated preference (ASP) survey to derive an estimate to the nearest dollar. A tobit model was fit to the data from the interviews to derive the estimate for value of time. A mean of $49.42 was found, with a 95% confidence interval from $40.45 to $58.39. Variation in the distribution of values is largely undetermined, with the exception of fleet operation, whether it is a for-hire truck fleet, or a private truck fleet. Journal of the Transportation Research Forum. 44:1 89-102. [bib] [poster]
- Yerra, Bhanu and David Levinson (2005) The Emergence of Hierarchy in Transportation Networks. Abstract: A transportation network is a complex system that exhibits the properties of self-organization and emergence. Previous research in dynamics related to transportation networks focuses on traffic assignment or traffic management. This research concentrates on the dynamics of the orientation of major roads in a network andabstractly models these dynamics to understand the basic properties of transportation networks. A model is developed to capture the dynamics that leads to a hierarchicalarrangement of roads for a given network structure and land use distribution. Localized investment rules - revenue produced by traffic on a link is invested for that link's own development - are employed. Under reasonable parameters, these investment rules, coupled with traveler behavior, and underlying network topology result in the emergenceof a hierarchical pattern. Hypothetical networks subject to certain conditions are tested with this model to explore the network properties. Though hierarchies seem to be designed by planners and engineers, the results show that they are intrinsic properties of networks. Also, the results show that roads, specific routes with continuous attributes, are emergent properties of transportation networks. Annals of Regional Science 39(3) pp. 541-553. [doi] [bib] [poster]
- Zhang, Lei and David Levinson (2005) Balancing
Efficiency and Equity of Ramp Meters. Abstract: A new freeway
ramp control objective - minimizing total weighted travel time is presented
in this study. This new objective function is capable of balancing
efficiency and equity of ramp meters, while the previous metering objective
- minimizing total absolute travel time is purely efficiency-oriented
and hence produces a most efficient but least equitable solution. When
certain assumptions hold, this metering objective is shown to be equal
to minimizing non-linearly weighted ramp delay. A simulation method
to achieve the new metering objective is developed and demonstrated
using the example of BEEX, a new ramp control strategy also developed
in this study, in a microscopic traffic simulator.
Keywords: Ramp Metering, Efficiency, Equity, BEEX, Value of travel time ASCE Journal of Transportation Engineering 131(6) pp.477-481. [doi] [bib]
- Zhang , Lei and David Levinson (2005) Road
Pricing with Autonomous Links. Abstract: This research seeks
to examine road pricing on a network of autonomous highway links. By
autonomous it is meant that the links are competitive and independent,
with the objective of maximizing their own profits without regard for
either social welfare or the profits of other links. The principal
goal of the research is to understand the implications of adoption
of road pricing and privatization on social welfare and the distribution
of gains and losses. The specific pricing strategies of autonomous
links are evaluated first under the condition of competition for simple
networks. An agent-based modeling system is developed which integrates
an equilibrated travel demand, route choice, and travel time model
with a repeated game of autonomous links setting prices to maximize
profit. The levels of profit, welfare consequences, and potential cooperative
arrangements undertaken by autonomous links will be evaluated. By studying
how such an economic system may behave under various circumstances,
the effectiveness of road pricing and road privatization as public
policy can be assessed.
Keywords: Network dynamics, road pricing, autonomous links, privatization, agent-based transportation model Journal of the Transportation Research Board #1932 pp. 147-155. [bib]
- Das, Shantanu and David Levinson (2004) A Queuing and Statistical Analysis of Freeway Bottleneck Formation. Abstract: A modified approach to treat traffic flow parameters (flow, density and speed) has been introduced in this paper. A queuing analysis has been conducted on traffic flow data on Interstate 94 in the Minneapolis-St. Paul metro area. A methodology has been developed to calibrate loop detector count data. Corrected flow data has been subjected to analysis using queuing analysis to compute densities and speeds on freeway sections. Statistical analysis identifies 'active bottleneck' locations on freeways and sections where bottlenecks occur because of disturbances caused by downstream bottlenecks propagating backwards in the form of shockwaves. A sample of six days on Interstate 94 was considered for the analysis. Our analysis reveals that the same section cannot always be characterized as a 'bottleneck' location; at some times it is active and at others, it is subject to downstream bottlenecks. Traffic flow characteristics change and that leads to changing situations on each freeway section. ASCE Journal of Transportation Engineering Vol. 130, No. 6, November/December 2004, pp. 787-795. [doi] [bib]
- Gillen, David and David Levinson (2004) Assessing the Investment in ITS: An Introduction., (pp. 1-16) in Assessing the Benefits and Costs of Intelligent Transportation Systems (David Gillen and David Levinson (co-editors)) Kluwer Publishers.
- Krizek, Kevin, Amanda Birnbaum, and David Levinson (2004) A Schematic for Focusing on Youth in Investigations of Community Design and Physical Activity. Abstract: This paper provides a first step to address special considerations for youth in a relatively new area of physical activity research. After reviewing the urgent need for novel approaches to increasing physical activity, the growing interest in the effects of community design is discussed. Although most discussion on this topic has focused on adults, there are important differences between youth and adults that warrant a special focus on youth and need to be accounted for. This article presents a schematic that accounts for how and where youth spend their time, decomposing the day into time spent in travel and time spent at destinations, and identifying portions of those times that are spent engaged in physical activity. By focusing on both spatial and behavioral dimensions of youth time, the schematic may help organize and advance scientific inquiry into the relationships between community design and physical activity specifically for youth. American Journal of Health Promotion19:1 33-38. [bib] [poster]
- Levinson, David and Wei Chen (2004) Traffic
Management Systems. This study uses regression analysis to evaluate
long-run traffic management system performance. Three important traffic
management systems in the Twin Cities metro area - Ramp Metering, Variable
Message Signs (VMS), and Freeway Service Patrol (the Highway Helper
Program) were evaluated with multiple regression models to predict
link speed and incident rate. We find that ramp meters increase freeway
link speed and reduce incident rate. Freeway Service Patrols increase
link speed when incidents are present. The results for variable message
signs are ambiguous.
Keywords: Traffic management system; Traffic system performance; Before-and-after study; Ramp Metering System; Variable Message Signs (VMS); Freeway Service Patrol; Highway Helper Program., (pp. 263-286) in Assessing the Benefits and Costs of Intelligent Transportation Systems (David Gillen and David Levinson (co-editors))Kluwer Publishers.
- Levinson, David, David Gillen and Pavithra Parthasarathi (2004) Freeway Service Patrols: A Stated Preference Analysis of Insurance Values. Highway assistance services, also called the freeway service patrols (FSPs), are one of the main approaches used by incident management programs. The objective of this study was to investigate the factors that contribute to people choosing to rely on the highway assistance services (FSP) in comparison to private assistance services such as the Automobile Association of America (AAA). Further the effectiveness of the Freeway Service Patrol was studied by carrying out a Benefit-Cost Analysis using Los Angeles as a test case. The results indicate that the probability that an individual would choose to depend on the highway assistance services depends on the key attributes like the annual fee of the program, the fee at the time of assistance, the time of waiting for assistance and cost of breakdown. The B/ C ratio for the Los Angeles FSP was calculated to be 5.91, (pp. 199-216) in Assessing the Benefits and Costs of Intelligent Transportation Systems (David Gillen and David Levinson (co-editors)) Kluwer Publishers.
- Levinson, David, Kathleen Harder, John Bloomfield, and Kasia Winiarczyk. (2004) Weighting Waiting: Evaluating the Perception of In-Vehicle Travel Time Under Moving and Stopped Conditions. Abstract: This paper describes experiments comparing traditional computer administered stated preference with virtual experience stated preference to ascertain how people value stopped delay compared with stop-and-go or freeflow traffic. The virtual experience stated preference experiments were conducted using a wrap around driving simulator. The two methods produced two different results, with the traditional computer assisted stated preference suggesting that ramp delay is 1.6 to 1.7 times more onerous than freeway time, while the driving simulator based virtual experience stated preference suggested that freeway delay is more onerous than ramp delay. Several reasons are hypothesized to explain the differences, including recency, simultaneous versus sequential comparison, awareness of public opinion, the intensity of the stop-and-go traffic, and the fact that driving in the real-world is a goal directed activity. However without further research, which, if any, of these will eventually prove to be the reason is unclear. What is clear is that a comparison of the computer administered stated preference with virtual experience stated preference produces different results, even though both procedures strive to find the same answers in nominally identical sets of conditions. Because people experience the world subjectively, and make decisions based on those subjective experiences, future research should be aimed at better understanding the differences between these subjective methodologies. Transportation Research Record: Journal of the Transportation Research Board #1898 pp. 61-68 [bib] [poster] [presentation]
- Levinson, David, Ning Li, Xi Zou, Brian Smalkoski, and Maryam Hashami
(2004) A Framework
for Analyzing the Effects of Spring Load Restriction. Abstract:
Spring Load Restrictions (SLR) impose load restrictions on heavy trucks
during the spring thaw period. Although the policies have been implemented
for many years, we are still unsure of their economic effects on truckers.
This paper overviews practices around the world and sets up a framework
to estimate the Benefit/Cost of the SLR policy. A freight demand model
in Minnesota was built to estimate the impacts of SLR on the freight
transportation pattern. The model allows various policy scenarios to
be tested before being tested in practice. A preliminary result of the
freight demand model shows the SLR policy increased truck Vehicle Kilometers
of Travel (VKT) in Lyon County, Minnesota by about 13 percent.
Keywords: Spring load restrictions, Benefit/Cost analysis, EMME/2, Freight demand model Journal of the Transportation Research Board No.1874 181-188 [bib]
- Levinson, David and Peter Rafferty (2004) Delayer Pays Principle: Examining Congestion Pricing with Compensation. Abstract: Despite its virtues, congestion pricing has yet to be widely adopted. This paper explores the issues of equity and use of toll revenue and several possible alternatives. The equity and efficiency problems of conventional (uncompensated) congestion pricing are outlined. Then, several alternatives are discussed and developed. A new compensation mechanism is developed, called the delayer pays principle. This principle ensures that those who arecause delay to others pay a toll to compensate those who are delayed. We evaluate the effectiveness of this idea by simulating alternative tolling approaches and evaluating the results across several measures, including delay, social cost, consumer surplus, and equity. Different tolling approaches can satisfy widely varying policy objectives, thus this principle is applicable in diverse situations. Such a system is viable and can eliminate some common hurdles of congestion pricing while remaining revenue neutral. International Journal of Transport Economics 31:3 295-311 [bib] [poster] [presentation]
- Levinson, David and Lei Zhang (2004) Evaluating
Effectiveness of Ramp Meters: Evidence for the Twin Cities Ramp Meter
Shut-off. Ramp meters in the Twin Cities have been the subject
of a recent test of their effectiveness, involving turning them off
for 8 weeks. This paper analyzes the results with and without ramp
metering for several representative freeways during the afternoon peak
period. Seven performance measures: mobility, equity, productivity,
consumers' surplus, accessibility, travel time variation and travel
demand responses are compared. It is found that ramp meters are particularly
helpful for long trips relative to short trips.Ramp metering, while
generally beneficial to freeway segments, may not improve trip travel
times (including ramp delays). The reduction in travel time variation
comprisesanother benefit from ramp meters. Non-work trips and work
trips respond differently to ramp meters. The results are mixed, suggesting
a more refined ramp control algorithm,which explicitly considers ramp
delay, is in order.
Keywords: Ramp Meters, Evaluation, Equity, Mobility, Accessibility, Productivity,Consumers' Surplus, Travel Time Variation, Travel Demand (pp. 145-166) in Assessing the Benefits and Costs of Intelligent Transportation Systems (David Gillen and David Levinson (co-editors)) Kluwer Publishers.
- Zou, Xi and David Levinson(2004) Financing and Deploying Automated Freight Systems. New technologies are bringing Automated Freight Systems (AFS), which aim to reduce congestion, mitigate environmental impacts and enhance public safety, to fruition. The financing and deployment issues of AFS differ from other Intelligent Transport System applications. This chapter briefly introduces major concepts of AFS. The financing strategies for these concepts are discussed, in which the government subsidies play an important role through the use of public-private partnership. Economies of scale and externalities of the current and new systems are discussed. In the discussion of the deployment of AFS, it is suggested that deployment schemes are highly correlated with financing strategies. ITS America Annual Meeting Proceedings.
- Zhang, Lei and David Levinson. (2004a) An
Agent-Based Approach to Travel Demand Modeling: An Exploratory Analysis. Abstract:
The paper develops an agent-based travel demand model. In this model,
travel demands emerge from the interactions of three types of agents
in the transportation system: node, arc and traveler. Simple local
rules of agent behaviors are shown to be capable of efficiently solving
complicated transportation problems such as trip distribution and traffic
assignment. A unique feature of the agent-based model is that it explicitly
models the goal, knowledge, searching behavior, and learning ability
of related agents. The proposed model distributes trips from origins
to destinations in a disaggregate manner and does not require path
enumeration or any standard shortest-path algorithm to assign traffic
to the links. A sample 10-by-10 grid network is used to facilitate
the presentation. The model is also applied to the Chicago sketch transportation
network with nearly 1000 trip generators and sinks, followed by a discussion
of possible calibration procedures. The agent-based modeling techniques
provide a flexible travel forecasting framework that facilitates the
prediction of important macroscopic travel patterns from microscopic
agent behaviors, and hence encourages the studies on individual travel
behaviors. Future research directions are identified, as are the relationship
between the agent-based and activity-based approaches for travel forecasting.
Keywords: Travel forecasting, Agent-based model, Travel behavior, Trip distribution, Traffic assignment, Shortest path algorithm, Activity-based model Transportation Research Record: Journal of the Transportation Research Board #1898 pp. 28-38 [bib]
- Zhang, Lei and David Levinson (2004b) Optimal
Freeway Ramp Control without Origin-Destination Information. Abstract:
This paper develops an analytical framework for ramp metering, under
which various ramp control strategies can be viewed as ramifications
of the same most-efficient control logic with different threshold values,
control methods, and equity considerations. The most-efficient control
logic only meters the entrance ramps nearest critical freeway mainline
sections so as to eliminate freeway internal queues, which is derived
from a new formulation of the optimal ramp control problem. Instead
of assuming the availability of real-time origin-destination information,
the new formulation takes advantages of the stability and predictability
of off-ramp exit percentages. Those properties of the off-ramp exit
percentages are supported by empirical data, and allow us to formulate
the optimal ramp control problem as a linear program whose input variables
are all directly measurable by detectors in real-time. The solution
is also tested on a real-world freeway section in a microscopic traffic
simulator for demonstration. Time-dependent origin/destination tables
and off-ramp exit percentages are compared as two alternative ways
to represent the true real-time demand patterns that are important
to freeway ramp metering.
Keywords: Ramp metering, Freeway operations, OD table, Off-ramp exit percentage Transportation Research part B Volume 38, Issue 10, December 2004, Pages 869-887. [doi] [bib]
- Zhang, Lei and David Levinson (2004c) Some
Properties of Flows at Freeway Bottlenecks. Abstract: Capacity
of a freeway segment should only be measured when it is an active bottleneck.
The properties of flows at active freeway bottlenecks bear on both
the definition of capacity and the procedure of capacity analysis.
Past studies have examined the flow features at bottlenecks on several
freeways in Toronto, Ontario, and San Diego, California. This study
examined twentyseven active bottlenecks in the Twin Cities metro area,
Minnesota, for a seven-week period. The analysis focuses on the properties
of pre-queue transition flows (PQF) and queue discharge flows (QDF)
averaged across various time intervals (thirty-second, daily average,
and long-run average). It is found that the percentage flows drop after
upstream queues form at all studied bottlenecks range from 2 percent
to 11 percent. The 30-second QDFs display high variation and should
not be assumed to be constant. The daily average QDFs at each studied
bottleneck follows a normal distribution based on two normality tests
and visual inspection of the normal probability plot. Results also
suggest that the long-run average QDFs (mean 2016 pc/ln/hr) and PQFs
(mean 2124 pc/ln/hr) are both normally distributed. The implication
of these empirical findings on capacity estimation is also discussed.
Keywords: freeway capacity, active bottleneck, queue discharge flow, pre-queue transition flow Journal of the Transportation Research Board No. 1883 122-131. [bib]
- Levinson, David (2003) The
Next America Revisited. Abstract: This paper examines Columbia,
Maryland, called "The Next America" by its founders in 1967. It compares
the planning goals and actual achievements over the third of a century
that the city has existed. The physical plan and social plan are discussed
in turn, and their reinforcing aspects considered. Issues of community
and identity, racial integration, education, religion, transportation,
shopping, work, and parks are addressed. Many of the goals have been
achieved; others have fallen short or evolved over time.
Keywords: Columbia, Maryland; Master Planned Community; New Town; James Rouse Journal of Planning Education and Research Summer 2003, Volume 22, Number 4, pp. 329-345. [doi] [bib]
- Levinson, David (2003) Perspectives
on Efficiency in Transportation. Abstract: This paper considers
the engineer's, economist's, manager's, and planner's perspectives
on effectiveness for transportation respectively. This paper examines
both the measures used in each perspective, weighs their advantages
and disadvantages for various purposes. The first section summarizes
various measures of mobility that are used to assess transportation.
This is followed by an exposition of transportation consumer surplus
and its limitations. Similar treatment of accessibility and productivity
are provided. The conclusions call for consideration of equity and
for taking the subjective point of view of the traveler rather than
the "objective" point of view of the omniscient planner/engineer/economist/manager.
Keywords: Performance Based Programming, Performance Measures, Systems Evaluation, Measures of Effectiveness, Mobility, Utility, Benefit-Cost, Productivity, Accessibility International Journal of Transport Management 1 pp.145-155. [doi] [bib] [presentation]
- Levinson, David (2003) The
Value of Advanced Traveler Information Systems for Route Choice. Abstract:
Over the next few years, driver behavior should become more informed
with the advent and deployment of in-vehicle navigation systems. This
paper analyzes systems that provide the driver the fastest path between
his or her current location and final destination, updated in real-time
to consider recurring and non-recurring congestion. The traveler's
full cost per trip is a bundle comprised of both expected travel time
and its reliability. This paper explores these topics from a theoretical
economic perspective and then simulates stylized cases. Simulation
results indicate that typical information benefits are at a maximum
on the precipice of congestion, when vehicles are arriving at a rate
of 95% of the capacity, while non-recurring congestion benefits are
Keywords: Transportation Information Systems, In-Vehicle Navigation, En-Route Guidance, Electronic Route Guidance, Advanced Traveler Information Systems Transportation Research part C 11(1) 75-87. [doi] [bib]
- Levinson, David and Elva Chang (2003) A Model for Optimizing Electronic Toll Collection Systems. Abstract: This paper examines the deployment of electronic toll collection (ETC) and develops a model to maximize social welfare associated with a toll plaza. A payment choice model estimates the share of traffic using ETC as a function of delay, price, and a fixed cost of acquiring the in-vehicle transponder. Delay in turn depends on the relative number of ETC and Manual Collection Lanes. Price depends on the discount given to users of the ETC Lanes. The fixed cost of acquiring the transponder (not simply a monetary cost, but also the effort involved in signing up for the program) is a key factor in the model. Once a traveler acquires the transponder, the cost of choosing ETC in the future declines significantly. Welfare depends on the market share of ETC, and includes delay and gasoline consumption, toll collection costs, and social costs such as air pollution. This work examines the best combination of ETC Lanes and toll discount to maximize welfare. Too many ETC lanes cause excessive delay to non-equipped users. Too high a discount costs the highway agency revenue needed to operate the facility. The model is applied to California's Carquinez Bridge, and recommendations are made concerning the number of dedicated ETC lanes and the appropriate ETC discount Transportation Research part A 37(4) 293-314. [doi][bib] [poster]
- Levinson, David and Ramachandra Karamalaputi(2003) Predicting the Construction of New Highway Links. Abstract: This paper examines new highway construction based on the status of the network, traffic demand, project costs, and budget constraints. The data span two decades and consist of descriptions of physical attributes of the network, the construction and expansion history, and average annual daily traffic values on each of the links. An algorithm is developed to designate adjacent and parallel links in a large network. A nonlinear cost model for new construction and highway expansion is developed for the Minneapolis-St. Paul metropolitan area. Results show that new links providing greater potential access are more likely to be constructed and that more links will be constructed when the budget is larger, which supports the underlying economic theory. The models developed here have important implications for planning and forecasting, allowing us to predict how networks might be altered in the future in response to changing conditions. Journal of Transportation and Statistics Vol. 6(2/3) 81-89. [bib]
- Levinson, David and Ramachandra Karamalaputi (2003), Induced
Supply: A Model of Highway Network Expansion at the Microscopic Level. Abstract:
This paper examines the growth of a network based on the present conditions
of the network, traffic demand, other demographic characteristics,
project costs, and a budget constraint. The effects of expanding a
link on its upstream and downstream neighbors, as well as on parallel
links are also considered. Data spans two decades and consists of data
on physical attributes of the network, their expansion history and
AADT values on each of the links. A non-linear cost model is developed
for the Twin Cities Metropolitan Area. Results show that high capacity
links are more likely to be expanded and a higher budget result in
more links being expanded. Large population in the surrounding region
deters two-lane expansion because of the high cost associated with
such an expansion but a one-lane expansion is favored. One of the important
results of this research is that the rate of network expansion has
decreased over the years.
Keywords: Network expansion, Cost Model, Transportation forecasting, adjacent links in a network. Journal of Transport Economics and Policy, Volume 37, Part 3, September 2003, pp. 297–318. [bib]
- Muthuswamy, Satya and David Levinson (2003) Buying
into the Bypass: Allowing Trucks to pay to use the Ramp Meter Bypasses. Abstract:
People make their route choices based on the delays they experience
but not on the delays they impose on others. Moreover different travelers
have different values of time. Road Pricing can be seen as the means
to optimize the use of a roadway by charging each traveler the cost
he imposes on others. This paper analyzes the opening of an HOV ramp
meter bypass to trucks that pay a toll. Trucks are similar to HOV as
both have a higher value of time than a single occupant car. Thus,
by saving time for these vehicles the system stands to gain. The toll
to be set was estimated under three scenarios - user benefit maximization,
profit maximization and system benefit maximization. A queue was simulated,
and based on the decision criteria the optimal toll was determined.
It is found that to maximize the system welfare, the high Value of
Time vehicles like trucks should be allowed to use the bypass for free,
but that raises some equity and operational issues. However a toll
that allows trucks to use the bypass improves the welfare over simply
prohibiting the trucks from the bypass.
Keywords: Trucks, HOV, Ramp Meter, Pricing Journal of the Transportation Research Forum Published in Transportation Quarterly 57(1), Winter 2003 pp. 81-92. [bib]
- Parthasarathi, Pavithra, David Levinson, and Ramachandra Karamalaputi (2003) Induced Demand: A Microscopic Perspective. Abstract: This paper analyzes the induced demand hypothesis using a disaggregate approach at the link level. A panel data set of Minneapolis/Saint Paul highway network for the years 1980-1998 is constructed. A model that predicts the traffic flow on the link in terms of Vehicle Kilometers Traveled (VKT) based on the flow and capacity conditions existing on the link in the previous years is specified and estimated. The flow and capacity conditions existing on the identified neighboring parallel links are also taken into account. Socio-demographic characteristics like population of the Minor Civil Division (MCD) to which the link belongs and the surrounding MCDs are also considered. The results indicate that capacity enhancements in the previous years, given by lane additions have a positive and significant effect on the VKT of the link, confirming the induced demand hypothesis. The elasticities are lower than reported in previous research, indicating the importance of separating new construction from the expansion of existing links. Urban Studies Volume 40, Number 7 June 2003 pp. 1335-1353. [doi] [bib] [poster]
- Zou, Xi and David Levinson (2003)
Vehicle Based Intersection Management with Intelligent Agents.
Signal-based intersection management will change when vehicles with intelligent capability are available in the future. Intelligent agents embedded in vehicle software will be responsible for vehicle control and route guidance. Intersection management can be achieved through the collaboration of these agents, without a centralized control infrastructure. This research focuses on the use of distributed multi-agent systems to provide microscopic adaptive control which might reduce traffic delay and chances of collisions at intersections. A hypothesized Mobile Ad-hoc Network provides communication links to connect the agents.
Keywords: Intelligent Agents, Adaptive Intersection Control ITS America Annual Meeting Proceedings.
- Levinson, David (2002) The
Economics of Traveler Information from Probes. Abstract: This
paper examines the economics of traveler information from probe vehicles
to understand how many probes are needed to provide useful information,
and how that probe information might be supplied to travelers. Probes
differ from permanently installed roadway detection devices both because
they provide information that is less current and because an information
system centered on this technology can be organized in the form of
private clubs rather than a government agency. This paper estimates
travel time associated with various shares of probes among the fleet
by simulating different levels of probes, information subscription,
and congestion. It examines the travel time savings under both recurring
and non-recurring congestion. When there is non-recurring congestion,
a low frequency of probes is sufficient to detect the incident and
enable information consumers to choose alternates. However, smoothing
the stochastic nature of traffic under recurring congestion requires
a relatively high share of probes (up to one-third of the fleet), depending
on the level of congestion.
Keywords: Transportation Information Systems, In-Vehicle Navigation, Advanced Traveler Information Systems, Probes, En Route Guidance Public Works Management and Policy 6(4) pp 241-250 (April). [doi] [bib]
- Levinson, David (2002) Identifying
Winners and Losers in Transportation. Abstract: This paper explores
the issues surrounding transportation equity for effects both external
and internal to transportation. Several examples of transportation "improvements" imposing
transportation costs on more individuals than who are benefited are
provided. Beyond counting the number of winners and losers, several
quantitative measures of equity are suggested. To that end, transportation
benefit cost analyses should include an "Equity Impact Statement".
This statement would consider the distribution of the opportunities
to participate in decisions and the outcomes of those decisions (in
terms of mobility, economic, environmental, and health effects) that
different strata (spatial, temporal, modal, generational, gender, racial,
cultural, and income) of the population receive. Policy makers would
then have additional information on which to base decisions.
Keywords: Environmental Justice, Social and Economic Factors, Equity, Benefit-Cost, Transportation Evaluation Transportation Research Record: Journal of the Transportation Research Board 1812 179-185. [bib] [presentation]
- Levinson, David and Seshasai Kanchi (2002) Road
Capacity and the Allocation of Time. Abstract: Additional highway
capacity, by increasing travel speed, affects the individual share
of time within a 24-hour budget allocated to various activities (time
spent at and traveling to home, shop, work and other). Some activities
will be undertaken more, others less. This paper extends previous research
that identified and quantified induced demand in terms of vehicle miles
traveled, by considering what type of demand is induced and which activities
are consequently reduced, using the 1990 and 1995 Nationwide Personal
Transportation Survey and Federal Highway Administration highway statistics
data. While total travel times have not seen any significant change
between the years 1990 and 1995, there is a significant change in activity
durations. Further, as a result of additional capacity, workers spend
less time traveling. Workers also spend more time at home and other
activities and less at work and shop. Non-workers, in contrast, travel
more, and spend more time shopping and at home, but less time at other
activities. This points out the differences in discretionary and non-discretionary
activities for workers and non-workers. It also suggests that there
are real gains from capacity in people's lives, at least in the short
term, as it is time, and not VMT, that individuals base decisions on.
Keywords: Time Use, Travel Behavior, Activity Patterns, Roadway Capacity, Induced Demand. Journal of Transportation and Statistics 5(1) pp 25-46. [bib] [presentation]
- Levinson, David, Seshasai Kanchi, and David Gillen (2002) Inter-technology
Effects in Intelligent Transportation Systems. Abstract: This
project examines the expected benefits of varying combinations of ITS
applications: Freeway Service Patrol, Changeable Message Signs, and
Ramp Metering. The research analyzes the simulated results of a stylized
network in a microscopic traffic simulator. The traffic network includes
parallel roadways, ramp meters and changeable message signs. We have
tested these technologies in various combinations. We measure effectiveness
as consumers' surplus and define a measure of inter-technology economies.
In brief, it is found that additional technologies are sub-additive,
and more benefits come from each technology in isolation than when
it is bundled with other technologies.
Keywords: Transportation System Management, Inter-technology Economies, Freeway Service Patrol, Changeable Message Signs, Ramp Metering, Intelligent Transportation Systems, Evaluation Transportation Research Record: Journal of the Transportation Research Board 1800 1-5. [bib] [presentation]
- Levinson, David and Bhanu Yerra (2002) Highway Costs and the Efficient Mix of State and Local Funds. Abstract: Transportation networks and governments are both hierarchically organized. In some states most highways are financed by state governments, while in other states similar roads are financed locally. Larger governments attain scale economies. However they also tend to be more bureaucratic and have higher operating costs, all else equal, due to problems such as span of control. This study relates highway expenditure with share of expenditure by state government so that a basis for determining how governments should share expenditure on all roads in a state to attain efficiency in highway costs. For each state three different costs are considered: capital outlay, operations and maintenance, and total costs. Two government layers are considered: state (including federal contributions) and local government. A series of regression models to predict different highway expenditures as a function of utilization, capacity, and funding shares are estimated. We find that there is a share of expenditures by each level of government which results in a minimum expenditure for each funding category (capital, operating). That minimum is not very far from typical state/local mixes found in many states. The results of this study can be applied in formulation of efficient network financing arrangements. Policies can be formulated that can help adjust the financial responsibilities of transportation networks between government layers. Transportation Research Record: Journal of the Transportation Research Board 1812 27-36. [bib] [presentation]
- Levinson, David and Atif Sheikh (2002)
Traffic Equilibration: The Case of the Twin Cities Ramp Meter Shut Off.
In Fall 2000, more than 430 ramp meters in the Twin Cities metropolitan area were shut down in order to evaluate the effectiveness of the metering system. This shutdown disturbed normal traffic patterns and thus traffic equilibrium. The purpose of our research is to examine how long it takes to establish a new equilibrium after a shock to the system, and thus establish the basis for how long these traffic studies should be carried out, as transportation analysts are generally concerned with comparing two equilibrium conditions. The initial results contradict our hypothesis that as the number of weeks since the shutdown increases, the week-to-week change in volume decreases. In fact our results show that not only are the week-to-week changes in volume is greater for shutdown case than for pre-shutdown case, those changes are rising as the experiment proceeded. More research is needed to examine the question of whether and how equilibria form, and we need to examine longer time slices for analysis to consider alternative definitions of equilibria.
Keywords: equilibrium, ramp metering, traffic flow, travel time., p. 580-587 Proceedings of International Conference on Traffic and Transportation Studies held in Guilin, China July 2002, ASCE Washington DC.
- Zhang, Lei and David Levinson (2002)
Estimation of Demand Response to Ramp Metering.
Ramp meters in the Twin Cities were turned off for 8 weeks in the Fall of 2000. Previous research has assumed demand to be fixed when analyzing ITS technologies, however analysis of this ramp metering shut down experiment, using traffic count data from freeway loop detectors, suggests otherwise: for discretionary trips (non-work trips), the presence of ramp meters encourages people to defer short non-work trips, which then take place during unmetered times. Similarly, the absence of ramp meters discourages long peak-period non-work trips, which are deferred to off-peak times. The effects of ramp metering on non-discretionary demand (work trips) are also reflected by the spreading of the peaks. The method of using freeway traffic count data to estimate demand shifts developed in this paper can also be applied to other freeway demand analyses.
Keywords: Ramp Meters, Elastic Demand, Non-work Trips, Twin Cities Ramp Meter Experiment. p. 674-681 Proceedings of International Conference on Traffic and Transportation Studies held in Guilin, China July 2002, ASCE Washington DC. [presentations]
- Zou, Xi and David Levinson (2002) Evaluation of Impacts of Adaptive Cruise Control on Mixed Traffic Flow. This paper addresses the impacts of Adaptive (Intelligent) Cruise Control (ACC) laws on traffic flow. Semi-automated vehicles, such as ACC Vehicles, with the capability to automatically follow each other in the same lane, will coexist with manually driven vehicles on the existing roadway system before they become universal. This mixed fleet scenario creates new capacity and safety issues. In this paper, simulation results of various mixed fleet scenarios under different ACC laws are presented. Explicit comparison of two ACC laws, Constant Time Headway (CTH) and Variable Time Headway (VTH), are based on these results. It is found that the latter one has better performance in terms of capacity and stability of traffic. Throughput increases with the proportion of CTH vehicles when flow is below capacity conditions. But above capacity, speed variability increases and speed drops with the CTH traffic compared with manual traffic, while the VTH traffic always performs better.. p. 762-779 Proceedings of International Conference on Traffic and Transportation Studies held in Guilin, China July 2002, ASCE Washington DC. [presentations]
- Levinson, David (2001) Why States Toll: An Empirical Model of Finance Choice. Abstract: This paper examines the question of why some states impose tolls while others rely more heavily on gas and other taxes. A model to predict the share of street and highway revenue from tolls is estimated as a function of the share of non-resident workers, the policies of neighboring states, historical factors, and population. The more non-resident workers, the greater the likelihood of tolling, after controlling for the miles of toll road planned or constructed before the 1956 Interstate Act. Similarly if a state exports a number of residents to work out-of-state and those neighboring states toll, it will be more likely to retaliate by imposing its own tolls than if those states don't. The policy implications for the future of congestion pricing are clear, if hard to implement. Decentralization of finance and control of the road network from the federal to the state, metropolitan and city and county levels of government will increase the incentives for the highway-managing jurisdiction to impose tolls. And tolls are a necessary prerequisite for an economically efficient strategy of congestion pricing. Journal of Transport Economics and Policy 35(2) 223-238 (May). [bib] [presentation]
- Levinson, David (2001) Financing Infrastructure Over Time. Abstract: A model to examine the choice by jurisdiction whether to finance roads with taxes or tolls is developed. The idea of decentralized, local control and multiple jurisdictions distinguishes this analysis from one where a central authority maximizes global welfare. Key factors posited to explain the choice include the length of trips using the roads, the size of the governing jurisdiction, the elasticity of demand to revenue instruments, and the transaction costs of collection - which dictate the size and scope of the free rider problem associated with financing. Spatial complexity in this problem results from the fact that jurisdiction residents use both local and non-local networks, and each jurisdiction's network is used by both local and non-local residents. The central thesis argues that, since jurisdictions try to do well by their residents who are both voters and travelers, the effects of a revenue instrument on local residents is a key consideration in the choice of that revenue instrument. Decentralization of control and lower toll collection costs are identified as conditions under which tolls would more likely become the preferred revenue instrument for highways. Journal of Urban Planning and Development American Society of Civil Engineers 127(4) 146-157 (Dec). [doi] [bib] [presentation]
- Levinson, David and Pavithra Parthasarathi(2001) An Economic Evaluation of Freeway Service Patrols. Highway assistance services, also called the freeway service patrols (FSPs), are one of the main approaches used by incident management programs. The objective of this study was to investigate the factors that contribute to people choosing to rely on the highway assistance services (FSP) in comparison to private assistance services such as the Automobile Association of America (AAA). Further the effectiveness of the Freeway Service Patrol was studied by carrying out a Benefit-Cost Analysis using Los Angeles as a test case. The results indicate that the probability that an individual would choose to depend on the highway assistance services depends on the key attributes like the annual fee of the program, the fee at the time of assistance, the time of waiting for assistance and cost of breakdown. The B/ C ratio for the Los Angeles FSP was calculated to be 5.91, IEEE Intelligent Transportation Systems Council (ITSC) Conference on Basic Research and Applications of Intelligent Transportation Systems (ITS), held August 25-29, 2001 in Oakland, California.
- Levinson, David and Lei Zhang (2001) Travel
Time Variability After A Shock: The Case Of The Twin Cities Ramp Meter
Shut Off. Ramp meters in the Twin Cities were turned off for
8 weeks in the Fall of 2000. This paper analyzes travel time variability
with and without ramp metering for several representative freeways
during the afternoon peak period. Travel time variability is generally
reduced with metering. However, it is found that ramp meters are particularly
helpful for long trips relative to short trips. The benefits from reducing
travel time variability with meters are on the order of 37% of the
benefits from reducing average travel time.
Keywords: Freeway Operations, Ramp Meters, Travel Time Variability, The Network Reliability of Transport (2003) Pergamon (editors Yasunori Iida and Michael Bell) (Presented at First International Symposium on Transportation Network Reliability, Kyoto, Japan July 30- August 1 2001). [presentation]
- Levinson, David (2000) Revenue Choice on a Serial Network. Abstract: A model to examine the choice by jurisdiction whether to finance roads with taxes or tolls is developed. The idea of decentralized, local control and multiple jurisdictions distinguishes this analysis from one where a central authority maximizes global welfare. Key factors posited to explain the choice include the length of trips using the roads, the size of the governing jurisdiction, the elasticity of demand to revenue instruments, and the transaction costs of collection - which dictate the size and scope of the free rider problem associated with financing. Spatial complexity in this problem results from the fact that jurisdiction residents use both local and non-local networks, and each jurisdiction's network is used by both local and non-local residents. The central thesis argues that, since jurisdictions try to do well by their residents who are both voters and travelers, the effects of a revenue instrument on local residents is a key consideration in the choice of that revenue instrument. Decentralization of control and lower toll collection costs are identified as conditions under which tolls would more likely become the preferred revenue instrument for highways. Journal of Transport Economics and Policy 34,1: 69-98. [bib]
- Levinson, David (2000) Monitoring Infrastructure Capacity. This paper examines the issues around monitoring of the capacity of public sector infrastructure to absorb land development.This paper first introduces Montgomery County¹s growth management system. It then offers two theories to justify monitoring infrastructure utilization for the purposes of establishing development capacity. The first, drawn from ecology is based on the notion of environmental carrying capacity. The second, from economics, employs the notion of externalities. However, neither of these directly translates to policy. The pragmatic position of establishing measures of effectiveness is then raised. These indicators must be situated within a decision framework. Because of the local and unique nature of projects, general rules will fail to provide efficient solutions. Thus, a more holistic evaluation framework is called for. Finally, some uses of the infrastructure capacity data in the context of land development are presented, with a focus on linking the financing of infrastructure with development approvals. p. 165-181 Land Market Monitoring for Smart Urban Growth Proceedings of Conference on Land Supply and Infrastructure Capacity Monitoring for Smart Urban Growth, Sponsored by the Lincoln Institute for Land Policy and the U.S. Department of Housing and Urban Development March 30 to April 1, 2000, Cambridge, Massachusetts. [presentation]
- Gillen David and David Levinson (1999) The Full Cost of Air Travel. Abstract: In this paper we review the theoretical and empirical literature on the cost structure of the provision of air transportation and specify and estimate our own cost functions. We develop a full cost model which identifies the key cost components and then we measure those costs component by component: user costs, carrier costs, infrastructure costs, time and congestion costs, noise costs, accident costs, and pollution costs. Applying the models to data for domestic air travel in the California Corridor, the total long run average cost is estimated to be $0.13 per passenger kilometer traveled. The single largest cost category is owning and operating a plane. In general, because of large fixed cost components, the average cost of infrastructure exceeds the marginal cost. Transportation Research Record :Journal of the Transportation Research Board 1662: 1-9. [bib] [presentation]
- Levinson, David (1999) Space, Money, Life-cycle, and the Allocation of Time. Abstract: Allocation of time to various activities is known to be a function of various demographic, socio-economic, seasonal, and scheduling factors. This paper examines those variables through exploration of the 1990 Nationwide Personal Transportation Survey, which has been inverted to track activity durations. The data are examined in single and multi-variate contexts. Two key issues are considered. First, to what extent does activity duration influence travel duration after controlling for activity frequency. This is tested with a set of models explaining travel duration. The data show activity duration does have positive and significant effects on travel duration, supporting recent arguments in favor of activity based models. Second, which is a more important effect in explaining the large changes in travel and activity patterns over the past thirty years accompanied by the increase in female labor force participation, the loss of discretionary time due to work, the change in metropolitan location, or the rise in per capita income. To examine this second question more rigorously, a choice model is constructed which examines both the decision to undertake an activity and the share of time within a 24 hour budget allocated to several primary activities: home, work, shop, and other activities. The utility functions for the activities are comprised of demographic, socio-economic, temporal, and spatial factors. The data also suggest that income and location have modest effects on time allocation compared with the loss of discretionary time due to working. Transportation 26: 141-171. [bib] [presentation]
- Levinson, David (1999) Tolling at a Frontier: A Game Theoretic Analysis. Frontiers provide an opportunity for one jurisdiction to remedy inequities (and even exploit them) in highway finance by employing toll-booths, and thereby ensuring the highest possible share of revenue from non-residents. If one jurisdiction sets policy in a vacuum, it is clearly advantageous to impose as high a toll on non-residents as can be supported. However, the neighboring jurisdiction can set policy in response. This establishes the potential for a classical prisoner's dilemma consideration: in this case to tax (cooperate) or to toll (defect).Even if both jurisdictions would together raise as much revenue from taxes as from tolls (and perhaps more since taxes may have lower collection costs), the equilibrium solution in game theory, under a one-shot game, is for both parties to toll. However in the case of a repeated game, cooperation (taxes and possibly revenue sharing) which has lower collection costs is stable. Proceedings of the 14th International Symposium on Transportation and Traffic Theory 173-187.
- Levinson, David (1998) Speed
and Delay on Signalized Arterials. Abstract: This research presents
a model to predict the influence of demand and capacity on the running
speed of signalized arterials in Montgomery County, Maryland. The model
separates the changes to link running speed due to same-direction traffic
and intersection approach delay from cross traffic. It is found that
flow has a small impact on link speed, each 1000 vehicles per lane
per hour reduces speed by 4 - 8 kph. Longer links have higher speeds,
indicating that they more closely approximate free-flow conditions.
A surprising result comes from measuring the effect of an additional
lane on link speed, after controlling for flow per lane. It is found
that there are slight diseconomies of additional lanes in terms of
speed, each additional lane is associated with somewhat slower speeds.
Measures of intersection and link travel times are also compared. Although
link running times exceed intersection stopped delay, total intersection
delay (stopped and approach) exceeds the delay caused by same-direction
traffic. This information can inform investment decisions about roadway
and intersection improvements.
Keywords: volume-delay function, signal delay, approach delay, traffic flow theory, running speed, highway capacity, Montgomery County Maryland ASCE Journal of Transportation Engineering 124: 3 258-264. [doi] [bib]
- Levinson, David (1998) Accessibility and the Journey to Work. Abstract: This study analyzes the effect of accessibility to jobs and houses at both the home and work ends of trips on commuting duration for respondents to a household travel survey in metropolitan Washington, DC. A model is constructed to estimate the effects of demographics and relative location on the journey to work. Analysis finds that residences in job-rich areas and workplaces in housing-rich areas are associated with shorter commutes. An implication of this study is that, by balancing accessibility, the suburbanization of jobs maintains stability in commuting durations despite rising congestion, increasing trip lengths, and increased work and non-work trip making. Journal of Transport Geography 6:1 11-21. [bib]
- Levinson, David, David Gillen, and Adib Kanafani (1998) A Comparison of the Social Costs of Air and Highway. Abstract: This paper provides a comprehensive survey of the literature on the measures of social costs, providing an indication of the state of engineering and economic literature. We operationalize the new thinking about which externalities seem appropriate to consider in an analysis of the transportation system. We construct measures of each externality: noise, air pollution, accidents, and congestion for the highway and air transportation modes, where possible as a function of the amount of output or use, rather than as simple unit costs. We find that noise is the dominant cost of air travel, followed by congestion, air pollution and accidents. For highway travel, accidents are the most significant cost, followed by congestion, noise, and air pollution. The social costs of highway travel are about 15% of the full cost of a highway trip, while the smaller social costs of air travel are only 5% of the full cost of an air trip. A highway trip generates four to five times as much externality as an air trip. Transport Reviews 18:3 215-240. [bib] [presentation]
- Levinson, David (1997) The Limits to Growth Management. Abstract: This paper reviews and critiques the growth management system in Montgomery County, Maryland with the intent of finding generalizable lessons. An overview of the twenty year old system is followed by an analysis of its consequences and implications. The system fails to provide effective price signals, rather relying on proactive command and control policies from the county government. Moreover the system fails to raise sufficient revenue for new infrastructure. The paper suggests that an alternative, reactive, approach, which links the threads of infrastructure financing and adequate public facilities by replacing quotas with a market based approach of cost-based prices, would be more equitable, efficient, and effective in implementing county goals. Environment and Planning b: Planning and Design 24: 689-707. [bib] [presentation]
- Levinson, David (1997) Job
and Housing Tenure and the Journey to Work. Abstract: Tenure
at jobs and houses, along with commuting patterns between home and
work were studied for residents of metropolitan Washington. Two alternative
potential outcomes were considered: (1) Because moving or switching
jobs can be used as an opportunity to reduce commuting duration in
an era of rising congestion, those who recently moved or changed jobs
should have shorter than average commutes; and (2) Because most new
residential construction is at the urban fringe, an area of longer
commutes, those who recently moved to new homes should have longer
commutes. Evaluation of the effect of commuting duration on job and
housing tenure suggests that those who move on average maintain commute
duration rather than having a major increase or decrease. This corroborates
the idea that there are offsetting factors, where increases in commute
lengths due to suburbanizing residences are counteracted by the correlated
process of suburbanizing jobs. Annals of Regional Science 31:451-471.
originally presented at Western Regional Science Association Meeting as part of Location, Relocation, and Journey to Work, San Diego, CA, February 1995. - winner of the Charles Tiebout Prize for Best Student Paper
- Levinson, David (1997) Road Pricing in Practice. The history of turnpikes from their first deployment in the 17th century through their decline in the 19th century, and some restoration in the 20th century is analyzed with a view to understanding the systematic causes of these changes. Key factors posited to explain both the rise and decline include the length of trips using the roads, the size of the governing jurisdiction, the degree of excludability, and the transactions costs of collection - which dictate the size and scope of the free rider problem associated with financing. This paper concludes with some discussion of what is required for turnpikes to become the preferred financing mechanism for highways. Chapter 2: Road Pricing, Traffic Congestion and the Environment, (1999) (ed. Ken Button, Erik Verhoef). Edward Elgar Publishers.
- Levinson, David, and David Gillen (1997) The Full Cost of Intercity Highway Transportation. Abstract: In this paper we review the theoretical and empirical literature on the cost structure of the provision of intercity highway transportation and specify and estimate our own cost functions . We develop a full cost model which identifies the key cost components and then estimate costs component by component: user costs, infrastructure costs, time and congestion costs, noise costs, accident costs, and pollution costs. The total long run average cost is $0.34 per vehicle kilometer traveled. The single largest cost category is freeflow travel time. While the marginal cost of infrastructure is higher than its average cost, indicating that new construction is increasingly expensive, the marginal cost of driving (user fixed and variable costs) is less than the average cost, indicating that by increasing travel the user can spread his fixed cost of a vehicle over more trips without penalty. Transportation Research -D 3:4 207-223. [doi] [bib] [presentation]
- Levinson, David and Yuanlin Huang(1997) A
Windowed Transportation Planning Model. Abstract: This research
develops and applies a transportation planning model that integrates
regional and local area forecasting approaches. While regional models
have the scope to model the interaction of demand and congestion, they
lack the spatial detail of a local approach. Local approaches typically
do not consider the feedback between new project traffic and existing
levels of traffic. Using a window, which retains the regional trip
distribution information and the consistency between travel demand
and congestion, allows the use of a complete transportation network
and block level traffic zones while retaining computational feasibility.
By combining the two methods, a number of important policy issues can
be addressed, including the implications of traffic calming, changes
in flow due to alternative traffic operation schemes, the influence
of micro-scale zoning changes on nearby intersections, the impact of
TDM on traffic congestion, and the consequences of a suburban light
Keywords: transportation planning model, traffic impact study, travel demand model, intersection control, window Transportation Research Record #1607: 45-54. [bib]
- Levinson, David and Ajay Kumar (1997). Density and the Journey to Work. Abstract: This paper evaluates the influence of residential density on commuting behavior across U.S. cities while controlling for available opportunities, the technology of transportation infrastructure, and individual socio-economic and demographic characteristics. The measures of metropolitan and local density are addressed separately. We suggest that metropolitan residential density serves principally as a surrogate for city size. We argue that markets react to high interaction costs found in large cities by raising density rather than density being a cause of those high costs. Local residential density measures relative location (accessibility) within the metropolitan region as well as indexing the level of congestion. We conduct regressions to predict commuting time, speed, and distance by mode of travel on a cross-section of individuals nationally and city by city. The results indicate that residential density in the area around the tripmaker's home is an important factor: the higher the density the lower the speed and the shorter the distance. However, density's effect on travel time is ambiguous, speed and distance are off-setting effects on time. The paper suggests a threshold density at which the decrease in distance is overtaken by the congestion effects, resulting in a residential density between 7,500 and 10,000 persons per square mile (neither the highest nor lowest) with the shortest duration auto commutes. Growth and Change 28:2 147-172. [bib]
- Levinson, David, Jean-Michel Mathieu, Adib Kanafani, and David Gillen (1997) The Full Cost of High-Speed Rail: An Engineering Approach. Abstract: This paper examines the full costs, defined as the sum of private and social costs, of a high speed rail system proposed for a corridor connecting Los Angeles and San Francisco in California. The full costs include infrastructure, fleet capital and operating expenses, the time users spend on the system, and the social costs of externalities, such as noise, pollution, and accidents. Comparing these full costs to those of other competing modes contributes to the evaluation of the feasibility of high speed rail in the corridor. The paper concludes that high speed rail is significantly more costly than expanding existing air service, and marginally more expensive than auto travel. This suggests that high speed rail is better positioned to serve shorter distance markets where it competes with auto travel than longer distance markets where it substitutes for air. Annals of Regional Science 31:2 189-215. [bib]
- Kumar Ajay and David Levinson (1995) Chained Trips in Montgomery County, Maryland. Abstract: This paper analyzes the 1987-88 Metropolitan Washington Council of Governments home interview survey to understand how work trips are combined into trip chains and to relate trip chaining with demographic and travel characteristics. The focus is on the work trips during the morning and afternoon peak period and the stops made on the way for performing nonwork activities. The work trips during the afternoon period are much more likely to involve trip chaining as compared to the morning period. Women are more likely to link work trips with other activities as compared to men. Stops are closer to home than work. ITE Journal May 1995 27-32. [bib]
- Levinson, David (1995) An Evolutionary Transportation Planning Model: Structure and Application. Abstract: This paper describes an evolutionary transportation planning model wherein the demand in a given year depends on the demand of the previous year. The model redistributes a fraction of the work trips each year due to the relocation of a household or taking a new job, while changes in distribution due to growth (or decline) are considered. This hybrid-evolutionary model is compared with an equilibrium model, wherein supply and demand are solved simultaneously. The reasons for preferring the evolutionary method to the equilibrium approach are several: (a) the ability to more easily use observed data and thereby limit modeling to changes in behavior; (b) additional realism in the concept of the model; (c) the provision of a framework for extension to integration with land use models; and (d) the additional information available to policy makers. Transportation Research Record #1493 64-73. [bib]
- Levinson, David and Ajay Kumar (1995) Activity, Travel, and the Allocation of Time. Abstract: This paper analyzes 1968 and 1987-88 metropolitan Washington, DC household travel surveys to understand the daily allocation of time among different activities of individuals classified by work status and gender. The increase in female labor force participation rates has produced an increase in overall time spent at work per person. The increase in work trips and the simultaneous increase in nonwork trips has resulted in less time spent at home. People are substituting money for time spent at home, buying household services outside the home. The group of individuals who work at home is analyzed separately to obtain an understanding of this growing segment. Journal of the American Planning Association. Fall 1995 61:4 458-470. [bib]
- Levinson, David and Ajay Kumar (1995) A Multi-modal Trip Distribution Model. Abstract: This paper presents a multimodal trip distribution function estimated and validated for the metropolitan Washington region. In addition, a methodology for measuring accessibility, which is used as a measure of effectiveness for networks, using the impedance curves in the distribution model is described. This methodology is applied at the strategic planning level to alternative HOV alignments to select alignments for further study and Right-of-Way preservation. Transportation Research Record #1466: 124-131. [bib]
- Levinson, David and Ajay Kumar (1995) Temporal Variations on the Allocation of Time. Abstract: This study investigates the allocation of time and trip-making across time-of-day, day-of-week, and month-of-year, as well as over the past forty years. Some interesting findings result. People are working much more, shopping somewhat more on weekends, and stay at home less today than forty years ago. Time spent in travel on each weekend day (Saturday or Sunday) exceeds that on any weekday, as it did forty years ago. Time spent shopping on a typical day in the busiest month (December) is more than double that in the least busy month (September). Monthly variations in daily time in travel exceed 10 percent. The time of day patterns of shop and other trips for workers and nonworkers are both rational: nonworkers peak in mid-day away from rush hour while workers peak just after work, indicating trip chaining. Transportation Research Record #1493: 118-127. [bib]
- Levinson, David and Ajay Kumar (1994) Integrating Feedback into the Transportation Planning Mode. Abstract: This research develops and applies a new structure for the transportation planning model that includes feedback between demand, assignment, and traffic control. New methods, combined with a renewed interest in transportation planning models prompted by the Clean Air Act of 1990 and the Intermodal Surface Transportation Efficiency Act of 1991, warrant a reconsideration of the traditional "four-step" transportation planning model. This paper presents an algorithm for feedback which results in consistent travel times as input to travel demand and output from route assignment. The model, including six stages of Trip Generation, Destination Choice, Mode Choice, Departure Time Choice, Route Assignment and Intersection Control is briefly outlined. This is followed by an application comparing a base year 1990 application with a forecast year of 2010. The 2010 forecast is solved both with and without feedback for comparison purposes. Incorporation of feedback gives significantly different results than the standard model.l. Transportation Research Record #1413 70-77. [bib]
- Levinson, David and Ajay Kumar (1994) Operational Evidence of Changing Travel Patterns. Abstract: This paper utilizes a traffic counts database covering a ten year period (1976-1985) to identify travel trends for Montgomery County, a suburb of Washington D.C. Generally, travel behavior is analyzed using person based travel survey data. The use of traffic counts to understand travel behavior is a relatively new approach. Unlike household surveys, which are typically characterized by respondent and sample bias, and require special effort for their collection, traffic counts are routinely collected by Departments of Transportation and provide the best available measure of observed traffic volumes. The study provides fresh evidence to support some of the earlier findings: an increase in lateral commuting as a share of travel, changes in work and non-work trip proportions, and increase in peak spreading. An interesting result in this paper relates to a more pronounced directionality in radial as compared with lateral trips. The relative symmetry of traffic flows along lateral routes compared with radial routes results in better utilization of the suburban road network. Non-work trips emerge as the more elastic trips, shifting to off-peak hours with an increase in congestion. ITE Journal, April 1994 36-44. [bib]
- Levinson, David and Ajay Kumar (1994) The Rational Locator: Why Travel Times Have Remained Stable. Abstract: This paper evaluates household travel surveys for the Washington metropolitan region conducted in 1968 and 1988, and shows that commuting times remain stable or decline over the twenty year period despite an increase in average travel distance, after controlling for trip purpose and mode of travel. The average automobile work-to-home time of 32.5 minutes in both 1968 and 1988 is, moreover, very consistent with a 1957 survey showing an average time of 33.5 minutes in metropolitan Washington. Average trip speeds increased by more than 20 percent, countering the effect of increased travel distance. This change was observed during a period of rapid suburban growth in the region. With the changing distributional composition of trip origins and destinations, overall travel times have remained relatively constant. The hypothesis that jobs and housing mutually co-locate to optimize travel times is lent further support by these data. Journal of the American Planning Association, Summer 1994 60:3 319-332. [bib]
- Kumar Ajay and David Levinson (1994) Specifying, Estimating and Validating a New Trip Generation Model: Case Study in Montgomery County, Maryland. Abstract: This paper discusses the development of an afternoon peak period trip generation model for both work and non-work trips. Three data sources are used in model development, a Household Travel Survey, a Census-Update Survey, and a Trip Generation Study. Seven one-direction trip purposes are defined, specifically accounting for stops made on the return trip from work to home. Trips are classified by origin and destination activities rather than by production and attraction, so reframing the conventional schema of home-based and non-home-based trips. Prior to estimating the model, the Household Travel Survey was demographically calibrated against the Census-Update to minimize demographic bias. A model of home-end trip generation is estimated using the Household Travel Survey as a cross-classification of the demographic factors of age and household size in addition to dwelling type. Non-home-end generation uses employment by type and population. The model was validated by comparison with a site based Trip Generation Study, which revealed an under-reporting of the relatively short and less regular shopping trips. Normalization procedures are developed to ensure that all ends of a chained trip were properly accounted for. Transportation Research Record #1413: 107-113. [bib]