25th Avenue Grade Separation Project

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 $205.9 million 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. We are 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 has rebuilt a new elevated Hillsdale Station with updated amenities. The station re-opened on April 26, 2021. 

The project 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.

The project is assessing improvements for bike safety implementation on E. 28th Avenue between El Camino Real and S. Delaware Street. In May 2021, the project added new shared roadway markings (sharrows) for bicyclists while we continue to work to align this segment with the Bicycle Master Plan-designated Class I bike facility planned for the northern sidewalk. On June 30, 2021, we held a virtual community meeting. Find our presentation here or view the recording of the meeting. See our Frequently Asked Questions for additional information. 

Current Project Milestones

Night on 28th Avenue - Mar 1 2021 - JYu PhotoOn April 26, 2021, the new Hillsdale Station opened off the new section of E. 28th Avenue making it easier for residents and visitors to access Bay Meadows, Hillsdale Shopping Center and more of what makes San Mateo a great place to live and work. 

On March 1, 2021, a new section of 28th Avenue opened between El Camino Real and S. Delaware Street. This new connectivity greatly improves the ability for our emergency vehicles to arrive quicker and our traffic to flow easier.

Also on March 1, 2021 all eastbound lanes 25th Avenue from S. Delaware to Palm Street closed until August to improve the underpass. One westbound lane will remain open until April 2021. 

In November 2020, we added additional flashing pedestrian beacons at 28th Avenue and Paddock Way to provide greater visibility to pedestrians crossing the street at this location. Now each pedestrian crossing on 28th Street in Bay Meadows has an enhancement to improve pedestrian safety. 

Rail Bridges

On 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

On June 30, 2021, we joined project partners at Caltrain to present an update (PDF or Youtube) on bicycle safety along the new E. 28th Avenue between El Camino Real S. Delaware Street. In 2019, Caltrain made a project presentation to San Mateo City Council on July 15. Click here to view the presentation (starts at hour 2:30). In May 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