CalTrain had its gestation in a 1973 study by the Southern California Association of Governments (SCAG), which recommended two daily roundtrips between Union Station and Oxnard. The train would use the Southern Pacific's Coast Line. Amtrak already operated a single long-distance train, the "Coast Starlight", over the route. SP objected to the proposal, alleging that the service would disrupt freight service on the single-track line, leading to a protracted dispute before the California Public Utilities Commission (PUC). The PUC ruled against the SP several times, with a final order in June 1982, ordering that SP operate the service beginning on October 18.