Caltrans Explores High-Speed Buses as Alternative to Rail in California

While high-speed rail has long captured the imagination of road-weary California travelers, Caltrans is exploring the feasibility of a different mode of expedited travel: high-speed buses.

Caltrans staff on Wednesday shared research on how high-speed buses capable of traveling anywhere from 80 to 140 mph might operate safely if found feasible on California’s freeway system.

Ryan Snyder, feasibility studies manager at Caltrans, said the purpose of the presentation was to stimulate a public discussion about how to best use California’s existing freeway system.

“ Are we using and managing this asset to its highest and best use? And if not, what could we do differently to meet today’s and tomorrow’s goals?” Snyder said, noting that if the freeway system were designed today, it would have been done “very differently.”

While the project is still in the research phase, and many questions remain about the significant engineering hurdles necessary to make the idea a reality, Caltrans staff said high-speed buses could transform long-distance travel with a faster, safer and more efficient mobility option for California.

The project envisions dedicated high-speed bus lanes, separated from other traffic, running down the middle of freeways and broken up by stations where passengers can get on and off. Snyder said initial designs could offer regional service along State Route 99, connecting communities like Bakersfield, Visalia and Fresno. Ideas for interregional service include using interstates 80, 5 and U.S. Route 101 to connect far-flung destinations like San Diego, Los Angeles and San Francisco.

At 100 mph, a high-speed bus trip from Los Angeles to San Francisco would take 3 hours and 50 minutes, Snyder said, shaving hours off current travel times by a personal vehicle.

Far from replacing California’s high-speed rail, Snyder said high-speed buses could complement and improve the value of the section of high-speed rail currently under construction from Merced to Bakersfield while the state works on securing funding to construct the rest of the proposed system from San Francisco to Los Angeles.

“ This could connect on the south end and could connect on the north end so that high-speed rail has more value than it would if it were just a disconnected segment of rail,” Snyder said.

The research takes inspiration from Adelaide, Australia’s O-Bahn guided busway, where buses reach speeds of 62 mph along a 7-mile dedicated path. But according to a preliminary investigation authored by Snyder in 2025, a significant obstacle is the lack of real-world examples of a high-speed bus system like the one envisioned by Caltrans.

“ High-speed buses could one day provide a speed advantage at a lower cost using existing freeway corridors once the technology is ready,” said Mehdi Moeinaddini, senior transportation planner at Caltrans. “But for now, trains and other established options remain more practical, and the right choice will depend on future economic analysis and the needs of each corridor.”

Moeinaddini said what fuel powers the buses — whether electric, hydrogen fuel cell, natural gas or something else — will depend on future innovations in the field.

Next steps include further research and testing on the design of buses, including aerodynamics, improved braking systems and other considerations to make the buses safer at such high speeds.

The research project has been submitted and is awaiting funding, according to Tori Kanzler, Chief of Caltrans Research Program Development Branch.