Project at a Glance

Title: Evaluating the benefits of light rail transit

Principal Investigator / Author(s): Houston, Douglas

Contractor: UC Irvine

Contract Number: 12-313

Research Program Area: Climate Change

Topic Areas: Behavioral Change, Sustainable Communities


This study evaluated the impact of the Expo light rail transit (LRT) line, which began service in south Los Angeles in 2012, on the travel and activity patterns of both long-term residents and those who moved to the area after service began. Findings support the implementation of Senate Bill 375 (SB 375) by evaluating the potential of transit investments for promoting compact, transit-oriented development goals of reducing vehicle miles traveled (VMT) and increasing active travel. Based on a quasi-experimental, longitudinal research design, results for longer-term residents indicate that living within walking distance (1 kilometer) of the line was associated with a reduction of 11 household VMT per day, a change likely due to their reduction in average car trip length. Living near the line was not associated with a significant increase in walking or bicycling trips. Residents who moved to the area after service began tended to be younger and had higher rental rates and income; those within walking distance of a station drove 8-10 more VMT per day and took longer car trips compared to longer-term households near a station but had rail ridership rates which were more than double that of longer-term households near a station.

NOTE: ARB is funding the third phase of data collection and analysis for this project. For the results from the first two phases of this project, visit

For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753

Stay involved, sign up with CARB's Research Email Distribution List