Caltrain Railyard Transformation Project Planned

The plan for a 20-acre development, called “San Francisco Railyards” at Fourth and King streets, is steadily taking shape. The current concept features an 850-foot mixed-use tower. If constructed it’d be the City’s second-tallest building, after the Salesforce Tower. 

Prologis is developing the site, in collaboration with Caltrain and the City and County of San Francisco. The present master plan features more than seven million square feet of housing and commercial space; precise details are still being hashed out. Construction is likely to be financed by private and public sources, including local, regional, and federal grants. The railyard project requires coordination with Transbay Joint Power Authority’s Portal project, which overlaps the Caltrain railyards.

Prologis expects to file a project application with the City this year and hopes to secure municipal approval by 2027. Infrastructure work could start within the next five years, contingent on funding. 

The railyard project design effort is being led by a team that includes Pickard Chilton, a New Haven, Connecticut-based architectural firm; the San Francisco field operations office of Magnusson Klemencic Associates, a Seattle structural and civil engineering firm; and Kristen Hall City Design, a San Francisco design firm.  The site is currently used as a train station and railyard storage and maintenance facility. 

“Under the current plan, Caltrain is leading the technical planning for the future rail station, rail facility, and track infrastructure to ensure the preservation of rail operations and maintenance. Prologis is leading the master plan and entitlement for the entire site, which requires the infrastructure and development plans for housing, office, and open space to work together,” said Genevieve Cadwalader, Prologis vice president and investment officer. 

The Pennsylvania Avenue Extension (PAX) is being developed at an adjacent site. PAX involves building underground rail lines for Caltrain and a future California High-Speed Rail along Seventh Street and Pennsylvania Avenue. That project would remove Caltrain crossings at Mission Bay Drive and 16th Street, eliminating the need for road users to wait while trains cross. 

Caltrain’s ridership has been increasing, with growth of more than a half-million passengers in 2024, and additional increases during the first quarter of 2025. 

“(The project would bring) critical improvements with lasting benefits for transit users, the local community, and the city-at-large. We look forward to working collaboratively with the City and community to thoughtfully address key issues, including land use, infrastructure investment, and impact fees,” said Cadwalader. 

Transformation of the railyard would substantially increase pedestrian and bicyclist traffic in the area. About 20 percent of riders across the Caltrain system use a bike. The Fourth and King station sees the most bike activity, said Navdeep Dhaliwal, Caltrain government and community affairs manager. 

“In all of the community discussions we’ve had already just about the site, walkability is far and away the most vocal amount of feedback we’ve received. It’s this really urgent desire to focus on improving safety of pedestrians, bikes, walkability, traffic calming, and better connectivity,” said Leigh Lutenski, Office of Workforce Development deputy director of joint development division. 

Prologis’ plan includes enhanced bike facilities, widened sidewalks, and new pedestrian- and bike-only connections. 

“As the engagement process continues, we will also continue to refine our plans in response to what we hear. A great example of this is the design of the Fifth Street crossing. The original concept allowed for vehicle through-traffic. We heard there was concern about it becoming a cut-through or freeway access point. In response, we revised the design to prioritize pedestrians and cyclists, removing through-traffic for cars,” said Cadwalader. 

Caltrain opened the Fourth and King Street station in 1975, with the idea that it’d be temporary. At the time, the area around the station was zoned primarily for industry. Since then, a great deal of housing, commercial buildings, and large facilities, like the Chase Center, have been built nearby. 

In 2021, Prologis and Caltrain launched a joint effort to evaluate railyard alternatives. The following year, the San Francisco Planning Department held meetings with stakeholders and area residents. In 2024, Prologis started to share information about the proposed redevelopment plan, with outreach to the Potrero Boosters and South Beach | Rincon | Mission Bay Neighborhood Association. Prologis plans to attend the Dogpatch Neighborhood Association’s (DNA) June meeting and a Potrero Dogpatch Merchants Association gathering in the next few months. Prologis has engaged participants in walking tours, as well as online meetings in which it’s shared conceptual images of the project. 

“Many have even expressed a desire for more height and density, often referencing global cities like Tokyo as models. There’s broad recognition that density near transit is smart policy. We’ve consistently heard that people choose to live in this neighborhood because they value its urban character and want to see it thrive. Most concerns and suggestions we have heard have been related to ensuring the streets feel safe and vibrant, that the retail is set up for success, and that there are usable, attractive places for people of all ages including community members, visitors, and commuters,” said Cadwalader. 

“Prologis has been receptive to comments about how they shape the differences in height between the taller towers and other structures nearby. Residents have asked where the height will be placed in the development, which is not certain yet, and how that will work best for the skyline. They haven’t expressed much concern about the concept of height itself,” said J.R. Eppler, Potrero Boosters president.

“They know they have parameters,” said Bruce Agid, South Beach | Rincon | Mission Bay Neighborhood Association board member, who lives across from the railyard. “They need high-density development to generate the funding to build a good project. The height of the large tower hasn’t been a concern among individuals who have come to Prologis’s meetings or been at meetings where Prologis has presented. Yet several City residents who have not attended the meetings have emailed me with questions about the height of the large tower and the density of the project.” 

“My only concern is that it won’t get built,” said Mike Linksvayer, a South Beach | Rincon | Mission Bay Neighborhood Association member who has gone on a site tour. “I see the new station and all the amenities that come with it as a huge benefit to the neighborhood.” 

He added that Prologis shared an array of design options.

“All would be an improvement over what is there now,” said Linksvayer. 

“For many people, this is the first place they see when they enter the City,” said Donovan Lacy, DNA vice president, who has attended Prologis’s online meetings. “Oracle Park and the Chase Center are right there. I look forward to the area beginning to have a “destination feeling.” Right now, it looks like an old Greyhound Bus station from the 1950s.” 

“I have questions about how this will come together. Even now, the area has a lot of moving parts,” said Gary Pegueros, a South Beach | Rincon | Mission Bay Neighborhood Association member, who has attended an on-site meeting. “There are Muni Metro rail lines, Muni buses, bikes, cars, and pedestrians all in one spot. Making what is already a highly dense area even more dense is a concern. They’ve been really transparent in discussing the different components of the project. They’ve also been good about listening to people and their comments. I see that they’re making an effort to incorporate what residents of this area want here.”