25th Avenue Grade Separation Project

25th Grade Separation Project renderingProject Description:

We are committed to improving safety, traffic flow and reducing train noise for our residents. In 1999, project planners started envisioning the project that is now known as the 25th Grade Separation Project. 

The $180 million Caltrain project is comprised of funding from the San Mateo County Transportation Authority, California High Speed Rail Authority, California State Department of Transportation (Caltrans), and the City of San Mateo. The City of San Mateo is the sponsoring partner.

The project will raise the train tracks, and slightly lower the road (grade separate), at E. 25th Avenue, and will create new east-west street connections at 28th and 31st avenues. As part of the project’s overall improvements, Caltrain will also build a new elevated Hillsdale Station with updated amenities at E. 28th Avenue.

This will improve safety for both motorists and pedestrians, and it will reduce local traffic congestion in San Mateo. Construction began in 2017 with an official groundbreaking. The project is in conformance with the San Mateo Rail Corridor Transit Oriented Development Plan.

Temporary Hillsdale Station Closure Starts May 16, 2020

As part of the Project, Caltrain will need to temporarily close Hillsdale Station for six months starting on May 16, 2020. Caltrain has arranged a number of benefits to the community during the 6-month closure. Visit its website dedicated to the station closure

To help riders during this temporary closure, parking at Belmont Station is free, Samtrans bus service on El Camino Real between Hillsdale and Belmont will be no charge, the free shuttle schedule between Hillsdale and Belmont can be found here


Screen Capture - 25th - Delaware - Train overhead Opens in new windowOn May 28, 2020, the first passenger train traveled above grade across 25th Avenue and Delaware Street. This milestone marked the beginning of the transition to a safer intersection in the neighborhood. Click the image here to watch the video. 

In late-2019, the project installed rail bridges over 25th, 28th, 31st avenues, along with the pedestrian bridge to the future Hillsdale Station, a major step in the progression of the project. 

Watch the Rail Bridge Installations

Watch a time-lapse of each rail bridge installation: E. 25th Avenue in July 2019, 28th Avenue in September 2019 and 31st Avenue in October 2019

Recent Presentations

Caltrain made its latest project presentation to San Mateo City Council on July 15, 2019. Click here to view the presentation (starts at hour 2:30). On May 8, 2019, Caltrain presented its latest project update to San Mateo’s S&I Commission (starts at minute 08:50).

How can you get project updates?

For weekly construction updates and to register for the weekly project emails, visit Caltrain’s project website.

Proposed pedestrian underpass at new Hillsdale Station rendering

Project Documentation