The Southern Pacific Railroad (SP) operated intercity passenger train services in California, including the Del Monte between San Francisco and Monterey, until the inception of Amtrak in 1971.

The annual operating cost would be $2.5 million, serving an estimated 190,000 to 234,000 passengers per year, assuming a schedule similar to the former Del Monte.

[1]: 50  Operation of a San Francisco–Monterey route under SP continued to be studied; with an annual ridership forecast of 210,000, gross revenue would be $1.1 million, yielding a higher first-year farebox recovery ratio than any previous public rail transit project in California.

[6]: 2–1 [7] Under the Business Plan, a one-way fare from Salinas was estimated to cost approximately $3.50 and increased ridership would bring in an extra $1.4 million in annual revenue.

A draft of the Caltrain Extension to Monterey County Alternatives Analysis was first published in 2006 and updated in 2007;[5] four alternatives were analyzed, with most assuming inter-county commuter rail service provided by Caltrain, extended from Gilroy to either Castroville or Salinas, connecting to Monterey via Marina on a new intra-county service provided by either bus rapid transit, light rail transit, or local buses: (articulated or rigid buses, trolley cars) (articulated or rigid buses, trolley cars) (streetcar-like DMUs) (streetcar-like DMUs) (streetcar-like DMUs) (streetcar-like DMUs) Also in 2006, with the Caltrain Express project completed, PCJPB began planning the electrification of the line, publishing results in the Project 2025 report (2006);[8] the electrification project would compete with MCRX for Caltrain's time and attention.

A draft environmental impact report (DEIR) published in 2006 stated the lack of public transportation options between Monterey County and the San Francisco Bay Area has resulted in increased private commuter vehicle traffic.

A layover yard would be added to accommodate Caltrain crews and maintenance, and the total cost of the Salinas improvements was estimated at US$39,705,000 (equivalent to $60,010,000 in 2023).

[9] This project depends on state and federal funding availability, a possible local sales tax measure, and an agreement with UPRR, the owner of the Coast Line.

[11] The switch to Capitol Corridor was cited as an advantage, since CCJPA had experience with commuter trains sharing service on UPRR-owned freight right-of-way.

[13] By March 2020, two daily Caltrain round trips were planned to begin in 2022 after the completion of the Salinas layover facility and trackwork at Gilroy.

[23] Pajaro/Watsonville station would be close to the intersection of Lewis and Salinas roads, south of the eastern leg of the existing rail wye where the Coast Line and Santa Cruz Branch meet.

The cost of the new intermodal station is estimated to be $69 million, including site preparation; for expanded service, an additional $30 M would be needed for modifications.

Track speeds are restricted to 50 mph (80 km/h) in this area, and drop further as trains negotiate more sharp curves at Chittenden Pass / Pajaro Gap, near a rock quarry.

Both companies were acquired by the Southern Pacific by 1887, which began offering Suntan Special excursion service from San Jose to Santa Cruz via the over-the-mountain line in July 1927.

[25]: 14  On October 12, 2012, SCCRTC acquired the Santa Cruz Branch from Union Pacific, as the Class 1 operator was not interested in allowing passenger service.

[27] The rail right-of-way owned by SCCRTC is sufficiently wide in almost all places to accommodate a single track alongside the planned 32 mi long (51 km), 12 ft wide (3.7 m) Monterey Bay Sanctuary Scenic Trail (MBSST), closely following the shoreline of Monterey Bay from the San Mateo County line to Pajaro.

[28][29] When finished, MBSST will extend the existing Monterey Bay Coastal Trail, spanning approximately 50 mi (80 km) from Lovers Point at Pacific Grove in the south to Wilder Ranch in the north.

[35] On July 13 of that year, Governor Gray Davis signed SB886 into law, which allowed TAMC to participate in any passenger rail service agreement between Caltrans and Amtrak in the San Francisco-San Jose-Monterey corridor.

BRT service will run over 6 mi (9.7 km) of the Monterey Branch Line right-of-way, between Marina and Sand City / Seaside.