California Air Resources Board

Analysis of Performance Measurement System (PeMS) data to estimate project-level, short-term induced travel from non-general purpose lane expansion projects

This project uses Caltrans Performance Measurement System (PeMS) data from four study sites in northern and southern California to estimate the effects of non-general purpose lane capacity expansions on traffic flows. These effects, often referred to as “induced travel,” are critical in determining the environmental impacts of transportation infrastructure projects and forecasting regional changes in vehicle miles traveled (VMT). While a number of studies estimate correlations between aggregate miles of roadways and total VMT, these results are not directly applicable to most current and future California roadway capacity projects, since non-general purpose lane expansions including high-occupancy vehicle (HOV) and high-occupancy toll (HOT) lanes are becoming an increasingly common strategy for expanding capacity on congested freeways.

The results indicate statistically significant increases in average speeds and traffic flows at all four study sites. The increases tend to be larger during peak hours, though increases are documented in most cases during both peak- and off-peak hours. The report also presents results from a set of “placebo tests” using data from locations without lane expansions for comparison purposes. These estimates reflect short-run local impacts and do not speak to medium- or long-run effects, spillovers to arterial street networks, regional impacts, or land use changes. This research fills a critical gap in the existing induced travel research by evaluating short-term, project level induced travel results specific to non-general purpose lane expansion that was previously missing.

Presenters

Prof. Michael L. Anderson

Michael Anderson is Professor of Agricultural and Resource Economics at the University of California, Berkeley. Dr. Anderson’s research interests include the areas of transportation economics, environmental economics, health economics, and applied econometrics, especially relating to questions of causal inference.
Dr. Anderson received his Ph.D. in Economics from the Massachusetts Institute of Technology (2006) and a B.A. in Economics from Swarthmore College (1999). He has published in a range of economics, scientific, medical, and statistical journals, including the American Economic Review, Review of Economic Studies, Journal of the American Statistical Association, BMJ, Annals of Internal Medicine, and Science.

Prof. Lucas W. Davis

Lucas Davis is the Jeffrey A. Jacobs Distinguished Professor at Berkeley Haas. His research focuses on energy and environmental markets, and, in particular, on electricity and natural gas regulation, pricing in competitive and non-competitive markets, and the economic and business impacts of environmental policy. He serves as co-editor of the American Economic Journal: Economic Policy and is a Research Associate at the National Bureau of Economic Research. Prior to moving to UC Berkeley in 2009, he was an Assistant Professor of Economics at the University of Michigan.