The Orange County Line began on April30, 1990, as the Orange County Commuter, an Amtrak-operated service between Los Angeles and San Juan Capistrano funded by the Orange County Transportation Authority.[5][6] The Orange County Commuter made a single weekday round-trip, departing San Juan Capistrano in the morning and returning in the evening.[7] Between July and December 1993 during the Orange County Commuter's final months, both the Commerce and Orange Transportation Center stations opened. Amtrak conveyed the route to Metrolink on March28, 1994, becoming the "Orange County Line" and Metrolink's fifth route.[8][9] Service expanded to eight trips in 1995.[10]
In October 2005, the Orange County Transportation Authority announced that it would increase service on the Orange County Line, running trains twenty hours daily, seven days a week every 30 minutes. The first part of the additional service was implemented in June 2006 with Saturday service, and July 2006 with Sunday service. The plan has drawn criticism[citation needed] as many Metrolink stations are located beyond walking distance from important destinations such as Disneyland and the adjacent Anaheim Convention Center, Knott's Berry Farm, and the Irvine Spectrum. Funds for new rolling stock and track improvements were allocated from the voter-approved Measure M half-cent sales tax, while critics[who?] had advocated using the money for bus operations or other transit service instead. To address some of these issues, OCTA operates a series of Stationlink shuttle routes that connect Metrolink stations in Orange County to nearby destinations.
As of 2019[update] service is provided seven days a week, with 29 trains on weekdays, and 8 on weekends. The AmtrakPacific Surfliner supplements Orange County Line service by providing limited stop service along the corridor and more service during mid-days, nights and weekends.
While the Orange County Line shares trackage with Amtrak's Pacific Surfliner trains, its northernmost stations (from Los Angeles to Fullerton, excluding Commerce) are shared with the 91/Perris Valley Line and nearly all of its other stations with the Inland Empire–Orange County Line (from Orange to Oceanside).
The October 2017 timetable shows ten weekday trains from Los Angeles to Oceanside and back, eight from Fullerton to Laguna Niguel and back, seven from Los Angeles to Laguna Niguel and back, four from Fullerton to Oceanside, and two from Los Angeles to Irvine and back.
Passengers that have monthly passes can use Pacific Surfliner trains between their station pairs on any day except for specific blacked out days by Amtrak for holidays and special events (such as events at Del Mar) on this line.