Vehicle Miles Traveled Metric

In 2013, the State of California passed Senate Bill 743 (SB 743), which requires all California jurisdictions to assess CEQA transportation impacts using Vehicle Miles Traveled (VMT), which measures the distance a vehicle will travel to a destination, by July 1, 2020. The City of Irvine began developing its new VMT methodology in Spring 2019. After months of extensive research, analysis, modeling, and community outreach, the City Council adopted the comprehensive update to the California Environmental Quality Act (CEQA) Manual, including the VMT Impact Analysis Guidelines, and related Traffic Study Guidelines update on June 23, 2020. 

As outlined in the updated Traffic Study Guidelines, the City’s methodology for evaluating the need for traffic improvements based on Level of Service (LOS) to address automobile delay will continue. As a matter of user convenience, the new VMT Impact Analysis Guidelines are also inserted in the Traffic Study Guidelines. 

The City Council’s approval requires staff to conduct a public forum approximately six to 12 months following adoption of the VMT Impact Analysis Guidelines to facilitate an open discussion and to consider adjustments to the methodology if needed. As a result, a technical update was approved by the Transportation Commission on November 2, 2021 and is available at the Traffic Study Guidelines link below. 

We welcome your feedback and input. 
To submit feedback and/or for technical assistance on the Traffic Study Guidelines (VMT and LOS) please contact Lisa Thai, Supervising Transportation Analyst, at

To add your contact information to the VMT email notification list, please contact Melissa Chao, Senior Planner, at

Important Links: