GIS-Based Analysis and Modeling of Non-Motorized Travel Behavior

(PI: Chandra Bhat)

Pedestrian and bicycle travel planning has been receiving increasing attention in the past decade at the local, regional and national levels because of the potential environmental, social, and health benefits of non-motorized travel. Specifically, pedestrian and bicycle travel can provide a safe and convenient alternative to automobile travel, thus reducing traffic congestion problems and mobile source emissions.  Similarly, non-motorized travel can contribute to the improved health of society, serve as a recreational outlet, and foster a socially vibrant community through increased opportunities for interaction among individuals. At the same time, however, the limited resources for funding transportation improvements requires that planners and policy makers estimate the usage and benefits of improvements in non-motorized transportation options against other alternative transportation projects. Such estimations require a good understanding of non-motorized travel behavior and the development of non-motorized travel demand models to predict future travel needs as well as to assess the impact on travel mode of policy actions aimed at encouraging bicycle and pedestrian travel.

Non-motorized travel behavior analysis and demand forecasting is in its infancy relative to motorized travel, as pointed out by several recent reviews of non-motorized travel methods such as Turner et al. (1997), Porter et al. (1999), Cambridge Systematics and Bicycle Federation of America (1999), and USDOT BTS (2000). These studies highlight the importance of collecting accurate data on non-motorized travel, understanding the behavioral elements of non-motorized travel, and developing quantitative models of non-motorized travel for both planning purposes (prioritizing projects, estimating reduction in automobile emissions, time and cost savings to travelers, etc.) as well as for safety analysis (for example, developing exposure rates from which measures of accident risk can be developed).

Many different sources of data may be used for non-motorized travel analysis (see USDOT BTS, 2000). Among these metropolitan household surveys and the NPTS survey provide detailed individual and household-level information about non-motorized travel usage for both work and non-work purposes. However, some practical limitations of typical metropolitan household surveys and the NPTS survey for non-motorized travel analysis are: (1) No recording of purely recreational trips, such as walking/bicycling for exercise, (2) underreporting of short work trips, (3) limited or no information on non-motorized travel patterns of young children, and (4) inability to assess the impact of weather conditions on non-motorized travel because of the narrow time period of survey data collection. In addition, metropolitan household surveys typically collect information from about 1000-2000 households, and such a small sample size does not provide adequate data for non-motorized travel analysis. The NPTS survey has a large sample size of about 15,000-20,000 households, but this is a national-level survey. At the metropolitan area level, the NPTS provides very few data points for non-motorized travel analysis.

In this research proposal, the focus will be on characterizing non-motorized mode usage and trip characteristics at the metropolitan area level. The research will use the recently collected 2000 San Francisco Bay Area Travel Survey (BATS) as the primary data source. The BATS data is ideally suited for such an analysis of metropolitan area non-motorized travel for several reasons. First, the 2000 BATS survey collected travel and demographic information from more than 15,000 households and is perhaps the most extensive metropolitan area travel survey to date. The total number of trip records in the survey is about 268,000, of which 29,532 (or 11% of total trips) are pursued using the walk mode and 3639 (or 1.4% of total trips) are pursued using the bicycle mode. These large number of walk and bicycle trips allows the comprehensive analysis of non-motorized trips. Second, the BATS survey is a time-use survey in which all activities in a two-day period are collected, including those activities that are purely recreational and are pursued by walking and/or bicycling. Third, the BATS survey obtained activity diary information on all members of a household, including children. This alleviates the problem of underreporting of short non-motorized trips undertaken by children. Fourth, the BATS survey data collection period spanned all the months of the year 2000. This enables a detailed study of seasonal fluctuations in non-motorized travel and the effect of weather conditions on non-motorized travel use. Fifth, the trips in the BATS survey have been geocoded to latitude and longitude. This will facilitate analysis at a high spatial resolution.

References

U.S. Department of Transportation, Bureau of Transportation Statistics (2000) Bicycle and Pedestrian Data; Sources, Needs and Gaps, BTS00-02, Washington, DC.

Cambridge Systematics and Bicycle Federation of America (1999) Guidebook on Methods to Estimate Non-Motorized Travel, FHWA-RD-98-165, Produced for the U.S. Department of Transportation, Federal Highway Administration, Washington, DC.

C. Porter, J. Suhrbier, and W. Schwartz (1999) Forecasting Bicycle and Pedestrian Travel: State of the Practice and Research Needs, Transportation Research Record, 1674, 94-101.

Turner, S., A. Hottenstein, and G. Shunk (1997) Bicycle and Pedestrian Travel Demand Forecasting: Literature Review, Research Report FHWA/TX-98/1723-1, Prepared for the Texas Department of Transportation.