The Los Angeles Metropolitan Transit Authority was a public agency formed in 1951. Originally tasked with planning for rapid transit in Los Angeles, California, the agency would come to operate the vestiges of defunct private transit companies in the city.

The Pacific Electric Railway Company, nicknamed the Red Cars, was a privately owned mass transit system in Southern California consisting of electrically powered streetcars, interurban cars, and buses and was the largest electric railway system in the world in the 1920s. Organized around the city centers of Los Angeles and San Bernardino, it connected cities in Los Angeles County, Orange County, San Bernardino County and Riverside County.