Committee Steers At-Grade Alternative into Environmental Review

Yesterday, the Diridon Station Steering Committee decided to move forward with the At-Grade Alternative as the best choice for a reconfigured and upgraded Diridon Station. The At-Grade Alternative will rebuild the station with the tracks at roughly the same elevation as they are today. The ground to the east and west of the station will slope gently downhill toward the station, creating a concourse below the surrounding ground level. The new design will make the underpasses below the tracks less steep than they are today. It will also add a pedestrian plaza as the entryway into a new ground level to the station, underneath where the first floor is today. 

Image: An artistic rendering of the At-Grade tracks passing over a rebuilt Santa Clara Street undercrossing, looking east. 

 The decision to move forward with the At-Grade Alternative was made after a two-year effort called the Business Case, which included technical analysis and community engagement activities. The Business Case was a joint effort of five agencies, including the City of San Jose, Caltrain, the Santa Clara Valley Transportation Authority, the California High-Speed Rail Authority, and the Metropolitan Transportation Commission (Partner Agencies). 

 "We’re excited to have reached this important milestone together," said Steering Committee Chair and County Supervisor Margaret Abe-Koga. "This is a transformative project, and its success depends on all involved agencies working as a cohesive team. Together, we can realize the future benefits it promises for transit service, the environment, and the regional economy." 

On the technical side, the Business Case considered the costs and benefits of different station design alternatives, evaluated construction challenges, and took impacts to the surrounding communities into account.  

Image: The Partner Agencies’ goals for the Diridon Station Project: making the station an economic and community development anchor, providing a great passenger experience, ensuring safe transit operations, building a sustainable and resilient station, and achieving strategic aims for the Partner Agencies and other stakeholders. 

The Business Case revealed a significant price difference between the At-Grade Alternative and an option called the Elevated Alternative, which would have elevated the tracks above the street. The estimated cost for the Elevated Alternative is as high as $4 billion more than the estimate for the At-Grade Alternative. The Elevated Alternative would also have serious impacts on a nearby properties, including a PG&E substation, and would erect a tall viaduct stretching for miles through the city. 

The Business Case also showed a fatal flaw in the Elevated Alternative:  the Caltrain maintenance facility, located just north of the station, would have to be disconnected from the tracks, meaning Caltrain would lose access from the south to this vital facility during the entire construction period (up to 10 years). After construction, the southern access into the facility would be altered significantly resulting in a negative impact on Caltrain operations indefinitely. That inevitability meant the Steering Committee simply could not approve moving forward with elevated tracks. 

In the community, the Business Case engagement team interacted with over 2,200 community members through 40 events and online activities. This team noted lots of enthusiasm for the redesign of the station in general. People want an iconic station that they can easily walk, bike, or take the bus to. The team also heard concerns and notes of caution, including a plea to consider the nearby community during and after construction and a desire to preserve much of the historic station building. This input was recorded and shared with the Steering Committee and will help shape the future design of the station. 

“Diridon is poised to be the busiest transit hub west of the Mississippi,” said Mayor Matt Mahan. “And this next phase of work will set us up for success when it comes time to secure funding and begin construction. I want to thank the thousands of community members who showed up, logged on, and stopped by the dozens of engagement opportunities and helped shape this project so it works for all of us here in San José.” 

In addition to the At-Grade Alternative, the Steering Committee approved several complementary efforts, collectively called the Program of Projects. They are meant to improve connectivity from one side of the tracks and station to the other and improve quality of life for residents and businesses near the tracks. The projects include rail crossing and roadway improvements at several key locations along the corridor: Park Avenue, San Carlos Street, Auzerais Avenue, and West Virginia Street. 

Image: An illustration of the track elevations for the existing station as compared to the At-Grade Station Alternative with grade crossings at intersecting streets. 

Later in 2025, the project will enter the environmental review process, which will refine the At-Grade Alternative and note any potential impacts on the environment, historical artifacts, and community health and well-being. The Partner Agencies will continue to update the Steering Committee quarterly. You can keep up with the project by visiting diridonsj.org.