The Coast Line is a railroad line between Burbank, California and the San Francisco Bay Area, roughly along the Pacific Coast. It is the shortest rail route between Los Angeles and the Bay Area. Though not as busy as the Surf Line, the continuation of the Coast Line southbound to San Diego, it still sees freight movements and lots of passenger trains. The Pacific Surfliner, which runs from the San Diego Santa Fe Depot to San Luis Obispo via Union Station in Los Angeles, is the third busiest Amtrak route, and the busiest outside of the Northeast Corridor between Washington D.C. and Boston.

The Bayshore Cutoff is the rail line between San Francisco and San Bruno along the eastern shore of the San Francisco Peninsula. It was completed by Southern Pacific (SP) in 1907 at a cost of $7 million, and included five tunnels, four of which are still used by Caltrain, the successor to Southern Pacific's Peninsula Commute service. Fill from the five tunnels was used to build the Visitacion or Bayshore Yard, the main SP classification yard near the city of Brisbane. The Del Monte was similarly rerouted over the line at some point in its operational history.