VMT and VMT Mitigation (SB 743)

LOS to VMT (via SB 743)

With the adoption of Senate Bill (SB) 743, the State of California changed the method of traffic analysis required through the California Environmental Quality Act (CEQA) for publicly and privately initiated projects. The law changed the way local jurisdictions, like the County of San Diego (County), analyze transportation impacts from development projects and identify mitigation measures to reduce those impacts. SB 743 became effective on July 1, 2020.

The previous practice of evaluating traffic transportation impacts used road congestion and delay or level of service (LOS). SB 743 requires the amount of driving and length of trips – as measured by "vehicle miles traveled" or VMT – be used to assess transportation impacts on the environment for CEQA review. These impacts will be reduced or “mitigated” by options such as Transportation Demand Management (TDM), increasing transit options, or providing for active transportation such as walking and biking. All jurisdictions have the option to tailor requirements to their unique communities.

Transportation Study Guide

As a resolut of a court order, staff prepared a revised Transportation Study Guide (TSG) for VMT that removed the previously adopted infill areas and small project screening thresholds. The TSG continues to utilize a VMT threshold using the regional average, which includes the entire countywide area and incorporated cities, as well as other screening criteria. In addition to VMT analysis in accordance with CEQA, the TSG also provides guidance and identifies methodology to analyze traffic operations and safety, referred to as a Local Mobility Analysis (LMA), as part of the County's discretionary planning process. On January 14, 2026, the Board of Supervisors adopted a new TSG. The new TSG, Board of Supervisors Minute Order, and additional resources are located below.

Resources and Adopted Transportation Study Guide:

Alignment with the Sustainable Land Use Framework

As part of the Board direction related to updating guidelines for VMT analysis during their February 9, 2022 hearing, the Board directed staff to develop a Sustainable Land Use Framework. Options for this process would include the following: identification of principles for sustainable development that could inform future land use decisions; and comparison of planning mechanisms to implement Board directed principles, including zoning overlays, specific plans, community plan updates, or a general plan update. Please visit the Sustainable Land Use Framework engage page to learn more: https://engage.sandiegocounty.gov/sustainableframework

Sustainable Land Use Framework Public Workshop

We want to hear from you! What do you think a safe, healthy, and vibrant community looks like in the future? As part of the County Board of Supervisors (Board) February 9th direction (Item #7), County staff was asked to develop options to inform the development of a Sustainable Land Use Framework. This framework would take into account various community needs including economic, social, development, and environmental needs and may inform future decision-making in the unincorporated area.

PDS will be holding a virtual public meeting to hear what you think. For more details, please see the information below.