Papers published in peer-reviewed journals
Hover over the article title link for abstract, click for downloadable paper in pdf. The digital object identifier [doi] links to the published version of the article. The BibTeX [bib] links to a BibTeX file containing references from the paper.
In Press | 2009 | 2008 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 | 1999 | 1998 | 1997 | 1996 | 1995 | 1994
In Press
- Iacono, Michael and David Levinson (2008) 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
uses.
Keywords: Land use, Twin Cities (Minnesota), Mathematical models, urban growth (accepted Transportation Research Record) [bib] [poster]. - Levinson, David (2009) 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
services.
Keywords: road pricing, equity, welfare, tolling, toll roads. Transport Reviews [bib] (in press). - Levinson, David, Feng Xie, Norah Montes de Oca (2006) 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. Presented at the First International Conference on Funding Transport Infrastructure in Banff, Canada August 2-3 2006. Networks and Spatial Economics (in press) [presentation] [doi]
- Liao, Chen-Fu, Henry Liu, and David Levinson (2006) 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
their curricula.
Keywords: Transportation Education and Training, Transportation Simulation, Roadway Geometry Design Presented at 88th Transportation Research Board Conference, January 2009, Washington , DC. (accepted Transportation Research Record) - Tilahun, Nebiyou Jonas, and David Levinson (2006) 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 presented at the 11th International Association of Travel Behaviour Research Conference in Kyoto, Japan August 16-20, 2006. Journal of Intelligent Transportation Systems (in press). [bib] [presentation] - Wu, Xinkai, David Levinson, and Henry Liu (2008) 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 (accepted Transportation Research Record) [bib] [poster] . - Xie, Feng and David Levinson (2008) 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 Presented at 88th Transportation Research Board Conference, January 2009, Washington , DC. [bib] [presentation] [doi] Journal of Economic Geography (in press) - Xie, Feng and David Levinson (2008) 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 alter- native 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, de- pending 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
pro jects 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 Presented at 88th Transportation Research Board Conference, January 2009, Washington , DC. [bib] [presentation] Transportation Planning and Technology (in press) - Xie, Feng, and David Levinson (2008) 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 (in press). - 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]
- Zhang, Lei and David Levinson (2004). Ramp
Metering and Freeway Bottleneck Capacity. Abstract: The objective
of this study is to determine whether ramp meters increase the capacity
of active freeway bottlenecks, and if they do, how. 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 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 (a 73% increase in the duration of the pre-queue
transition period), accommodating higher (2%) flows during the pre-queue
transition period, and increasing queue discharge flow rates after
breakdown (3%). The two-capacity hypothesis about flow drops after
breakdown was also examined and results strongly suggest the percentage
flow drops at various bottlenecks follow a normal distribution (mean
5.5%, standard deviation 2.3%). The implications of these findings
on the design of efficient ramp control strategies are discussed, as
well as future research directions.
Keywords: Ramp metering, freeway capacity, active bottleneck, queue discharge flow, Twin Cities ramp meter shut-off Transportation Research: A Policy and Practice (in press). [bib]
2009
- 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] - 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 (2007) 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] - 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 (2007) 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 (2007) 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
tested.
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]
2008
- 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 presented at the 86th Annual Meeting of the Transportation Research Board in Washington, DC, January 21-25 2007.Transportation Research Record: Journal of the Transportation Research Board #2046 pp 85-93 [doi][TRB Paper #(07-2496)] - 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
versa.
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. Presented at Royal Society Discussion Meeting Networks: Modelling and Control. (September 2007) 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
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 06-0760 presented at the 85th Annual Meeting of the Transportation Research Board in Washington, DC, January 22-26 2006. 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. 06-1714, presented at the 85th Annual Meeting of the Transportation Research Board in Washington, DC, January 22-26 2006 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) presented at 84th Annual Meeting of Transportation Research Board in Washington, DC, January 9-13th 2005 and presented at 2nd International Conference on Transportation Network Reliability. Christchurch, New Zealand August 20-22, 2004. 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. Presented at the World Conference on Transport Research in Berkeley, California June 24-28 2007. Journal of Transport Economics and Policy Sept. 2008 42(3) pp. 435-461. [download]
2007
- 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. presented at 2004 World Conference on Transport Research, Istanbul. ASCE Journal of Urban Planning and Development 133(4) 250-254. [bib] - 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]
2006
- 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, 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] - 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. [bib] [poster]
2005
- 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. [bib] - 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]
2004
- 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]
- 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, 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]
- 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]
2003
- 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
much greater.
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]
2002
- 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]
2001
- 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]
2000
- 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]
1999
- 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]
1998
- 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]
1997
- 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.
[bib] [presentation]
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, 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. [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
rail line.
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]
1995
- 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]
1994
- 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]