Impact of a Light Rail Transit Line on Physical Activity: Findings from the Longitudinal Travel Assessment and Community (TRAC) Study.

Introduction: Increasing transit infrastructure could increase transit use and result in higher physical activity if users actively travel to access transit. Few studies have rigorously examined transit use and physical activity change from before to years after among residents living close versus farther away from new transit options. Methods: An initial sample (n=722) of residents living either close (<1 mile network distance; exposed) or farther away (>1 mile network distance; unexposed) from future new light rail transit (LRT) stops in the Seattle/King County area were recruited and assessed prior to LRT opening and again 1-2 and 3-4 years later. At each assessment timepoint, residents wore an accelerometer and GPS data logger for 7 days and completed a 7-day travel log and demographic and attitudinal survey. Difference-in-difference analyses examined longitudinal change between those exposed versus unexposed to LRT in physical activity, walking (both utilitarian and recreational), and transit-related walking, and transit use. Results: There was no differential change by LRT exposure in overall physical activity (including or not including light intensity physical activity), recreational walking, or utilitarian walking, with most decreasing significantly in both exposure conditions through follow-ups. There was a differential change in transit-related walking, with those exposed to LRT slightly increasing such physical activity to the most distal follow-up, but the difference from the unexposed condition was modest (<2 minutes/day). There was no substantial differential change over time in transit use by LRT exposure. Conclusions: Exposure to a new light rail line did not markedly change the frequency of transit use of nearby residents, but did result in a small increase in transit-related walking relative to those unexposed. This did not differentially change the amount of overall physical activity or time spent walking compared to residents living farther away from the new LRT.