Access to Destinations: Development of Accessibility Measures
Ahmed El-Geneidy , David Levinson
Report no. MnDOT 2006-16
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.