Access to Destinations: How Close is Close Enough? Estimating Accurate Distance Decay Functions for Multiple Modes and Different Purposes
Michael Iacono , Kevin Krizek , Ahmed El-Geneidy
Report no. Mn/DOT 2008-11
Existing urban and suburban development patterns and the subsequent automobile dependence are leading to increased traffic congestion and air pollution. In response to the growing ills caused by urban sprawl, there has been an increased interest in creating more "livable" communities in which destinations are brought closer to ones home or workplace (that is, achieving travel needs through land use planning). While several reports suggest best practices for integrated land use-planning, little research has focused on examining detailed relationships between actual travel behavior and mean distance to various services. For example, how far will pedestrians travel to access different types of destinations? How to know if the "one quarter mile assumption" that is often bantered about is reliable? How far will bicyclists travel to cycle on a bicycle only facility? How far do people drive for their common retail needs?
To examine these questions, this research makes use of available travel survey data for the Twin Cities region. A primary outcome of this research is to examine different types of destinations and accurately and robustly estimate distance decay models for auto and non-auto travel modes, and also to comment on its applicability for: (a) different types of travel, and (b) development of accessibility measures that incorporate this information.