California High-Speed Rail

California High-Speed Rail (CAHSR) is a publicly funded high-speed rail system being developed in California by the California High-Speed Rail Authority. Phase 1, about 494 miles (795 km) long, is planned to run from San Francisco to Los Angeles and Anaheim via the Central Valley. Due to mainly political roadblocks, only the Initial Operating Segment (IOS) has advanced to construction. It is the middle section of the San Francisco–Los Angeles route and spans 35% of its total length. These 171 miles (275 km) in the Central Valley will connect Merced and Bakersfield. Revenue service on the IOS is projected to commence between 2031 and 2033 as a self-contained high-speed rail system, at a cost of $28–38.5 billion. With a top speed of 220 mph (350 km/h), CAHSR trains running along this section would be the fastest in the Americas.

The high-speed rail project was authorized by a 2008 statewide ballot to connect the state's major urban areas and reduce intercity travel times. Phase 1 targets a nonstop travel time of 2 hours and 40 minutes from San Francisco to Los Angeles, compared to about nine hours on the existing Amtrak San Joaquins. California legislative overseers do not expect that the 2 hr 40 min target will be achieved. A proposed Phase 2 would extend the system north to Sacramento and south to San Diego, for a total of 776 miles (1,249 km).

Construction of the IOS as part of Phase 1 began in the Central Valley in 2015 with completion planned in 2020. From January 2015 to December 2023, a total of $11.2 billion had been spent on the IOS – which has 119 miles (192 km) under active construction – and on upgrades to existing rail lines in the San Francisco Bay Area and Greater Los Angeles, where Phase 1 is planned to share tracks with conventional passenger trains. Regulatory clearance has been obtained for the full route connecting San Francisco and Los Angeles, which includes the IOS. However, with a current price tag of $130 billion, the Authority has not yet received sufficient funding commitment to construct the segments from the IOS westwards to the Bay Area or southwards to Los Angeles, both of which would require tunneling through major mountain passes. As of April 2025, the High-Speed Rail Authority's intermediate goal is to connect Gilroy (70 miles south of San Francisco) to Palmdale (37 miles north of Los Angeles) by the year 2045, through partnership with private capital. As of 2024, the entirety of Phase 1 was projected to cost $106.2 billion.

Supporters of the project state that it would alleviate air traffic and highway congestion, reduce pollution and greenhouse gas emissions, and provide economic benefits by linking the state's inland regions to coastal cities. Opponents argue that it is too expensive, and that the funds should be spent on other transportation or infrastructure projects. The route choice has been controversial, along with the decision to construct the first high-speed segment in the Central Valley rather than in more heavily populated parts of the state. The project has experienced significant delays and cost overruns caused by management issues, legal challenges, and lack of a complete funding commitment.