Funding our Transportation System 


How is the 2021 Regional Plan funded?

Funding for the 2021 Regional Plan will not be available all at once—rather, it will come into the region over time. This means that project implementation will have to be carefully phased based on anticipated revenue projections and other factors. The 2021 Regional Plan will include a detailed funding strategy that will be reviewed at the state and federal levels. The funding strategy must be built on a revenue forecast—based on trends for existing revenue sources as well as reasonable assumptions about potential changes in the future—of what the region will be able to afford through 2050. Numerous factors, ranging from the state of the economy to new state and federal legislation, can affect the availability and use of the funding.

Estimated in today’s dollars, rough order of magnitude costs for the proposed transportation network will be available in April 2020. Through a more detailed analysis that will be conducted in summer 2020, projects and programs will be phased for implementation through 2050. Following this process, detailed cost estimates will be available in late 2020. 

Where do funds come from? How can we invest them?

Funding for our transportation network comes from a variety of sources at the federal, state, and local levels. The majority of current federal and state funding sources have restrictions on their use, and we don’t have the authority to interchange them. These constraints come with specific provisions from Congress or the State Legislature. Restrictions may specify certain modes of transportation—such as highway, bus, rail, or bike/pedestrian projects—as well as when, where, and how funds should be spent.

There also are constraints on which dollars can be used by SANDAG and which dollars are distributed through SANDAG to agencies such as Caltrans and the transit agencies (for highway and transit operations and maintenance needs) or the cities and San Diego County (for their local streets and roads).

SANDAG has purview over a relatively small portion of the overall funds included in the Regional Plan, and therefore must continue to work creatively to determine how to best leverage the available dollars. One way the San Diego region has supplemented scarce federal and state dollars for transportation projects is by establishing local revenue sources. Revenues from the countywide TransNet half-cent sales tax, other local taxes, developer impact fees, fares, tolls, and additional local sources now fund roughly half of our transportation improvements.

What is TransNet? How do we use its revenues?

is a countywide half-cent sales tax dedicated exclusively to transportation improvements and environmental conservation in the San Diego region. Originally approved by voters in 1987, a 40-year extension of TransNet was approved with two-thirds voter support in 2004. During the last 30 years, TransNet revenues have been leveraged to secure billions of dollars in federal and state matching funds to help make the region’s big-picture vision for transportation into a reality. As with other funding sources, the TransNet ballot measures included a list of specific projects with funding priority.

Hundreds of projects—highway, bus, and rail projects as well as bike and pedestrian projects, local street repairs, habitat conservation efforts, and grant programs—have been delivered through the TransNet program. Explore completed projects using the interactive TransNet Story Map at

More information about the TransNet program and its Independent Taxpayer Oversight Committee is available at