MTI Report WP 12-14

Research Report Designing Road Diet Evaluations: Lessons Learned from San Jose’s Lincoln Avenue Road Diet (PDF 6.3MB)

Principal Investigator: Hilary Nixon, Ph.D.


This report analyzes traffic impacts from the 2015 implementation of a pilot “road diet” on Lincoln Avenue, in the City of San Jose, California, comparing data on traffic volumes and speeds from before and after the road diet was implemented. The analysis looks at impacts on both the road diet location itself and on surrounding streets likely to have been impacted by traffic diverted off the road diet segment. The results within the road diet zone were as expected, with falling volumes and numbers of speeders. The all-day data aggregated by street type (e.g., neighborhood streets, major streets) showed limited overall negative impacts outside the road diet segment. These summary results do not tell the entire story, however. Individual locations, particularly among the neighborhood streets, saw more noticeable negative impacts. The report ends with recommendations for best practices in designing and conducting road diet evaluation studies.


Hilary Nixon, Ph.D.

Dr. Nixon is professor of urban and regional planning at San José State University. Her research and teaching interests in environmental planning and policy focus on the relationship between environmental attitudes and behavior, particularly with respect to waste management and linkages between transportation and the environment. She holds a BA from the University of Rochester in environmental management and a PhD in planning, policy, and design from the University of California, Irvine.

Asha Weinstein Agrawal, Ph.D.

Dr. Agrawal is director of the Mineta Transportation Institute’s National Transportation Finance Center and professor of urban and regional planning at San José State University. Her research and teaching interests in transportation policy and planning include pedestrian and bicycle planning, travel behavior and opinion surveys, and transportation finance. She also works in planning and transportation history. She earned a BA from Harvard University in folklore and mythology, an MSc from the London School of Economics and Political Science in urban and regional planning, and a PhD from the University of California, Berkeley, in city and regional planning.

Cameron Simons

Cameron Simons works as a market analyst at Trulia. He holds a BS in economics from San José State University.


Authors: Hilary Nixon, Ph.D., Asha Weinstein Agrawal, Ph.D., and Cameron Simons
Published: July 2017
Keywords: Evaluation, speeding, traffic safety, traffic volume, arterial streets