An analysis of relationships between urban form (density, mix, and jobs: housing balance) and travel behavior (mode choice, trip generation, trip length, and travel time).

摘要

The purpose of this project is to empirically test the relationship between land use density, mix, jobs-housing balance and travel behavior at the census tract scale for two trip purposes; work and shopping. This is the first project within a research agenda to discover ways to plan and implement urban forms that increase accessibility and reduce dependence on the single occupancy vehicle (SOV). This project provides input into policies at the national, state and local level targeted at the reduction of SOV travel and provides direct input for urban form policies (e.g. the Washington State Growth Management Act or Vision 2020 in the Central Puget Sound).;This research employs a correlational research design in which non-urban form factors (e.g. demographics and level of service) are used as control variables. Data for travel behavior variables (modal choice, trip generation, trip distance, and travel time) was obtained from the Puget Sound Transportation Panel (PSTP). Data for urban form variables (gross employment density, gross population density, mixing of uses, and jobs-housing balance was obtained from the U.S. Census Bureau, The Washington State Employment Security Department (ESD), and the King County Assessor's Office. The databases developed for this study are composed of these data sources matched together by one common variable; the census tract. These databases are structured around two separate units of analysis the trip and the tract. Relationships between urban form and modal choice was analyzed at the tract level while urban form relationships with trip generation, distance and travel time were analyzed at the trip level.;Simple statistical analytical techniques are used to identify relationships between urban form and travel behavior variables including T-Tests, Linear Correlation, multiple regression, and cross-tabulation. Findings from the application of these statistical techniques indicate that employment density, population density, and mixing of uses is negatively correlated with SOV usage and positively correlated with transit usage and walking for both work and shopping trips. Employment density, population density, and mixing of uses is negatively correlated with trip distance and positively correlated with trip generation for work trips. Travel time is positively correlated with employment density and negatively correlated with mixing of uses for work trips. Jobs housing balance is negatively correlated with trip distance and travel time for work trips. Transit, walking, and SOV usage were found to have non-linear relationships with population and employment density for both work and shopping trips. An analysis of density thresholds was conducted to identify where significant changes in SOV, transit, and walking occur.;Policy implications from this research are vast however more research is needed to make the findings more applicable. A study of the costs and benefits of implementing higher levels of density, mix, and jobs-housing balance is essential. Analysis of urban form travel behavior relationships in smaller geographic areas and in other regions of the United States would also increase the generalizability of the findings.