Improving Regional Travel Demand Models for Bicycling

John Gliebe, Resource Systems Group, INC

Co-investigator:

Summary:

With growing concerns over the lack of physical activity, increase in greenhouse gases, and other threats to sustainability, planners, engineers, and policy makers are looking for ways to increase the use of alternative modes of travel. Bicycling is one such option. According to the 2001 Nationwide Household Travel Survey (NHTS), over 60% of all personal trips are five miles or less in length – a reasonable distance to ride a bike – and nearly 40% are two miles or less. Despite the potential, only about one percent of the trips people make in the U.S. are on bicycles, including less than five percent of trips under ½ mile. In contrast, bicycling is a popular form of recreation throughout the country. A 2002 nationwide survey of people 16 and older found that 27% had bicycled in the past 30 days, with recreation being the most common purpose (National Highway Traffic Safety Administration & Bureau of Transportation Statistics, 2003). There is very little research in the U.S. on bicycling. What does exist provides some general indications, but is limited in scope and often employs unreliable methods (BTS, 2000). Moreover, the primary tool used by public agencies to plan urban transportation systems – travel demand models – rarely includes bicycles as a separate mode. Metro, Portland’s regional transportation planning agency, is generally regarded as having some of the most sophisticated land use and travel demand models in the country. And, among large urban areas in the U.S., this region has one of the highest rates of bicycle travel. Despite these facts, Metro’s travel models address bicycles in a very simple manner, for example assuming all cyclists travel at the same speed. Without more sophisticated modeling tools, planners are not able to accurately evaluate infrastructure options that involve cycling. One reason Metro’s (and other regions’) models do not adequately address the bicycle as a mode of transportation is a lack of data. Models are built using travel and activity surveys, which usually don’t include enough bicycle travel to develop better models. This project will address these problems. For the past two years, we have collected data from over 150 bicyclists on their bicycle trips using GPS. This work was funded by the Robert Wood Johnson Foundation and OTREC. From those two projects we have been able to evaluate why and where people bicycle, including identifying different types of cyclists. The OTREC funding has been used to focus specifically on route choice behavior, comparing the characteristics of the cyclists’ routes with those of the shortest paths. The research project proposed here takes that several steps further. The GPS data already collected will be used to develop a bicycle component to Metro’s travel demand model. This will be done, in part, by estimating the relative utilities of various types of facilities and factors, e.g. bike boulevards, arterials with and without bike lanes, low traffic streets, hills, etc. In addition, the results will be used to improve a bicycle route planning guide (ByCycle) that is currently available.

Project Details

Project Type:
Research
Project Status:
In Progress
End Date:
December 31,2009
UTC Grant Cycle:
OTREC 2009
UTC Funding:
$60,232
TRB RIP:
17976