The context for regional transportation and land use planning in California has changed dramatically in the past few years. State Senate Bill (SB) 375 brings new, and still evolving, requirements for metropolitan planning organizations to align transportation and land use in ways that meet GHG emission reduction targets from the transport sector. The targets have been set by the California Air Resources Board (ARB), and the greater Los Angeles region’s first plan to comply with those targets has been published as the Southern California Association of Government’s (SCAG’s) Regional Transportation Plan / Sustainable Communities Strategy (RTP/SCS). By 2020, the ARB target requires
that the SCAG region reduce GHG from the ground transport sector by 8%, and the target requires a 13% reduction by 2035. Both targets are from a 2005 per capita baseline. The SCAG RTP/SCS anticipates meeting and even exceeding the targets. Yet compliance with targets is based almost entirely on transportation forecasting models, potentially limiting the evolution and flexibility of the SB 375 policy framework in ways discussed below.
This policy context brings new challenges for transportation data collection and project evaluation. SB
375 requires metropolitan planning organizations (MPOs) to credibly quantify the impact of transportation investments on GHG emissions. The research summarized here gives results of a before-‐ after, experimental-‐control group method to evaluate the impacts of transportation investments. This is a promising technique, but one that has only rarely been applied in transportation planning. By applying this method, we can illuminate how a broad range of transportation projects and policies could be similarly evaluated.
Beyond questions of impact measurement, Los Angeles’ rail transit investment has the potential to transform neighborhoods – positively or negatively. The Expo Line Phase I corridor (the subject of our study) passes through lower income, predominantly minority communities, and is seen by residents along the corridor as both a possible catalyst for economic development and a potential threat. Will the Expo Line trigger new business activity that will provide jobs and retail opportunities in the corridor? Or will the Expo Line cause property price appreciation that may price out renters and displace some current corridor residents? Or possibly (even likely) might there be a combination of both effects, with
complicated net effects? Those questions are beyond the scope of this travel behavior study, but a large body of theory argues convincingly that changes in land use, economic development, and quality of life are longer-‐term downstream effects that flow from (and are caused by) more short-‐term changes in patterns of accessibility and travel behavior (e.g. Handy, 2005). This study’s focus on travel behavior change is an important first step in broader efforts to understand the longer-‐term impacts of the Expo Line.