The San Mateo 101 Express Lanes Project is currently underway. This multi-year, multi-agency project was initiated to reduce traffic congestion and encourage carpooling and transit use on U.S. Highway 101.
The project will create 22 miles of express lanes on U.S. Highway 101 from the San Mateo County/Santa Clara County line to I-380 in South San Francisco. The San Mateo 101 Express Lanes will seamlessly connect to the express lanes being constructed in Santa Clara County. A goal of the express lanes is to enable travel speeds of 45 mph or greater, resulting in reduced and more reliable travel times.