A Report on Participant Sampling and Recruitment for Travel and Physical Activity Data Collection

The substantial investments now being made in transit yield benefits that go beyond managing traffic congestion relief, and include improved environmental quality and potential gains in human health due to increased physical activity. Past research on the effects of such infrastructure investments on mode choice and physical activity has been hampered by cross-sectional designs that limit the ability to draw causal inference. A 5-year $3.3 million study was submitted to the National Institutes of Health (NIH). The study takes advantage of the introduction of light rail transit (LRT) in Seattle. Using a case-control longitudinal panel design, 1000 adults living either close to (within 1 mile; case) or far from (control) an LRT station will be assessed prior to (baseline), soon after (post 1), and more than 2 years after (post 2) the introduction of LRT service. It is hypothesized that residents living close to LRT will have an increase in transportation-related walking and total physical activity relative to residents living farther away. Individuals’ walking will be assessed via integrated information from portable GPS and a 7-day travel diary, and physical activity assessed via accelerometry. Neighborhood built environment will be assessed via parcel-level land use evaluation. Changes in non-LRT infrastructure and availability (e.g., bus routes) will also be considered. The proposal has been favorably reviewed once by NIH. The resubmission deadline is in early March. The December 2008 project start date does not give the research team the time needed to set up the protocol and collect the baseline data before Light Rail opens in July 2009. As a result, the research team has sought bridge funding for a May 2008 project start. TransNow support will contribute to this bridge funding and insure that baseline data can be collected on 1000 subjects for 7-day travel patterns. The study natural experiment design has strong potential to make a significant contribution to scientific knowledge and to transportation policy. The prospective evaluation of changes in the same individuals’ transport modes and physical activity over a period of marked change in transportation and built environment is a rare, but potent test of the impact transportation investments on behavior.