Understanding the Influence of Local Option Sales Tax Measures on SB 375

In California, voter-adopted sales tax measures for transportation purposes (so called “self-help” measures) constitute a substantial share of all funds provided for transportation, comprising about 30% of capital spending from sources compiled in regional transportation plans in California in 2010. Twenty-five California counties have active sales tax measures in place, expected to raise hundreds of billions of dollars for transportation investments by mid-century. The ballot measures, which extend for periods of 20 years or more, specify projects to be funded, and have become a popular way to raise revenue as federal and state transportation funds have been reduced.

In 2017, the share of funding allocated for local roads and highways accounted for an average of 61% across all California county sales tax measures, higher than the share allocated towards transit (31%). This share of funds for transit was higher than in state-level funding directed to transit (about 20%) in FY 2018-19. However, some concerns have also been raised about the sales tax measures, such as about their lack of alignment with regional planning priorities, their “lock-in” of funding commitments over long time periods, and their political imperative to satisfy multiple interests at election time, making performance orientation difficult.

Little recent research has considered how the evolution of county sales tax measures for transportation in California, considered in terms of their composition of funding allocations by mode and use, have affected regional transportation plans developed by the state’s Metropolitan Planning Organizations (MPOs) under the provisions of Senate Bill (SB) 375 (2008). SB 375 requires that MPO plans, which must include county-funded projects if they include any federal funding component, help reduce greenhouse gas (GHG) emissions. In 2019, the California Air Resources Board (CARB), the agency responsible for overseeing SB 375 implementation, evaluated progress achieved by MPOs in reducing GHGs under the law. With vehicle miles traveled (VMT) and transport-related GHGs rising statewide, CARB expressed concern that on-the-ground development patterns are “not on track” for achieving SB 375 goals. Given this concern, and with a number of county sales tax measures scheduled to expire (and likely to be up for renewal) soon, now is an opportune time to assess how current sales tax measures and their administrating agencies—county transportation authorities—are influencing the direction of MPO regional plans and outcomes.

This research project will assess how county sales tax measures affect funding allocations and policy and program choices adopted in MPO long- and short-range plans in California’s four largest regions, with an eye to how and whether county-led projects affect VMT reduction, based on project types and uses funded, on MPO modeling of impacts on VMT/GHGs where available, and considering other factors that MPO planners identify as important in this regard. In addition, the project will assess how and whether other programmatic work by the county transportation authorities is supporting VMT reduction; some of the agencies have been working, for example, to assist localities in implementing Senate Bill 743 (2013), under which analysis and mitigation, required under the California Environmental Quality Act of transportation impacts of development projects, must work to reduce VMT. Based on document research and interviews with regional and county planners as well as other experts, the project will consider how county measures have affected the regional planning and funding process in furtherance of SB 375 objectives. With San Francisco Bay Area policymakers currently seeking to place a multi-county sales tax measure on the ballot, now is an opportune time to investigate these challenges and opportunities.


Research Area