Dynamic accessibility using space-time paths for public and private transportation

This dissertation uses time geography techniques to compare the relative accessibility provided by public transit and the private automobile in Salt Lake City. While many factors affect individuals' decisions on transit use, differences in the accessibility afforded by transit compared to other modes play a large role. This dissertation analyzes accessibility in two ways, by comparing auto and transit travel times between actual origins and destinations, and comparing travel time from selected origins to all possible destinations in the Salt Lake City area.;To expand the examination of accessibility beyond the origins and destinations from the WFRC survey, this dissertation uses space-time prisms and potential path areas to examine accessibility from nine locations within the Salt Lake City metropolitan area. This analysis examines both the area that can be accessed under a fixed time budgets and overall accessibility patterns over the entire Salt Lake metropolitan area. The space-time prisms and potential path areas are generated for four different times of day using travel times from the WFRC's regional transportation model.;The use of these time-geographic tools provides previously unavailable insights into the accessibility implications of transit use. This dissertation also introduces new methods for analyzing large volumes of space-time data;The actual origins and destinations are based on survey data gathered from riders on the bus and light-rail systems for the Wasatch Front Regional Council (WFRC). These data are used to construct space-time paths for both their actual transit trips and theoretical auto trips between the same origins and destinations. The automobile portions of these trips are constructed using time-of-day based travel times from the WFRC's regional transportation model. The auto and transit paths are compared using a variety of measures, including some novel ones developed for this study. Combined with demographic data from the survey, these comparisons shed light on how accessibility affects a person's decision to use transit.