Development of Accessibility Measures

(Minnesota Department of Transportation, $55,000, 2 years, PI-David Levinson)

Abstract:

Transportation systems are designed to help people participate in activities distributed over space and time. Accessibility indicates the collective performance of land use and transportation systems and determines how well that complex system serves its residents. This research project comprises three main tasks. The first task reviews the literature on accessibility and its performance measures with an emphasis on measures that planners and decision makers can understand and replicate. The second task identifies the appropriate measures of accessibility, where accessibility measures are evaluated in terms of ease of understanding, accuracy and complexity, while the third task illustrates these accessibility measures. During this process a new accessibility measure named “Place Rank” is introduced as an accurate measure of accessibility. In addition, several previously-defined accessibility measures are reviewed and demonstrated in this report including Cumulative opportunity and gravity-based measures. The gravity-based measure is widely used in the literature yet cumulative opportunity tends to be easier to understand and interpret by the public, planners, and administrators. A major contribution of this research is the comparison of accessibility measures over time and among various modes. Effects of accessibility on home sales are also tested. Homebuyers pay a premium to live near jobs and away from competing workers. Accessibility promises to be a useful tool for monitoring the
land use and transportation system, and assessing and valuing the benefits of proposed changes to either land use or networks.

Main Project Web Site

Final Report

• Access to Destinations: Development of Accessibility Measures Report # 1 in the series Access to Destinations Study Report # 2006-16 ( http://www.lrrb.org/PDF/200616.pdf )

Presentations and Publications

• El-Geneidy, Ahmed and David Levinson (2007) Title: 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]