SM 101 Express Lanes Project

Caltrans-sm-101-express-lanes-bannerActive Dates - Feb 2020 - 2022

To sign up for weekly or quarterly updates, email with the subject line ’Weekly’ or ’Quarterly’ to 101express@dot.ca.gov or follow the project on Twitter @CaltransD4.

Project History

In 2019, Caltrans broke ground on its multi-year, multi-agency San Mateo 101 Express Lanes Project, which aims to reduce traffic congestion and encourage carpooling and transit use on U.S. Highway 101 in San Mateo County. The project will create 22 miles of express lanes on U.S. Highway 101 from I-380 in San Bruno to the San Mateo County/Santa Clara County border. The San Mateo 101 Express Lanes will then seamlessly connect to the express lanes being constructed in Santa Clara County. 

At public meetings in San Mateo in late 2018, staff met with residents who aired concerns about potential noise issues due to the wall reconstruction. The project's Environmental Assessment report noted that the project will cause a negligible increase in noise for this area. More information is found on the project's Noise Analysis Fact Sheet

In December 2019, Caltrans returned to our City for an update on the project. Watch that update here. On June 17, 2019, Caltrans presented an update on the project to City Council. Click here to watch the video (starts about 2:48).