SANDAG, the San Diego Association of Governments, is a leading transportation authority in San Diego County. With the mission to reduce traffic congestion and improve quality of life, SANDAG implements a variety of transportation projects and manages funds generated by the 20-year TransNet program. Since its approval in 1987, the TransNet program has been instrumental in funding major transportation improvements in the county.

In 2004, voters extended the program until 2048 through Proposition A. The funds are allocated towards highway, transit, and local road projects aimed at reducing traffic congestion. SANDAG, in partnership with Caltrans, MTS, and NCTD, is actively involved in Early Action Projects, which include the expansion and enhancement of major interstates such as I-5, I-15, and I-805.

Other projects include the extension of the Trolley system, the implementation of Bus Rapid Transit, and the development of a circulator transit system in the University City area. Through its Independent Taxpayer Oversight Committee (ITOC), SANDAG ensures the proper expenditure of TransNet funds and adherence to voter mandates. With its commitment to transportation improvements and environmental conservation, SANDAG continues to play a crucial role in shaping San Diego County's transportation landscape