By Jackie Lavalleye : californiapolicycenter – excerpt
… In December 1991, the role of the Associations of Governments was expanded by passage of the Intermodal Surface Transportation Efficiency Act of 1991. This law provided more power over planning to metropolitan areas; thereby, increasing the authority of metropolitan planning organizations over transportation-related activities. In short, every project related to roads, pedestrians, traffic, and all other issues of relevance to transportation must be discussed by, coordinated with, and approved by these agencies…
Four of the largest Associations of Governments in California are the San Diego Association of Governments (SANDAG), the Southern California Association of Governments (SCAG), the Metropolitan Transportation Commission (MTC), and the Sacramento Area Council of Governments (SACOG). SCAG is the largest Association of Government in the country based on population and geographic territory size. MTC also has shared responsibilities with the Association of Bay Area Governments (ABAG). As of late, MTC and ABAG have been working toward consolidating their staffs for improved efficiencies… (more)
This article from 2017, explains the creation and goals of the regional state agencies.