Work begins this week from the San Mateo County/Santa Clara County line to Whipple Avenue on the San Mateo 101 Express Lanes Project. This is a multiyear, multiagency (Caltrans, San Mateo County Transportation Authority, C/CAG) project 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 the San Mateo County/Santa Clara County border to I-380 in San Bruno and seamlessly connect from express lanes also being constructed in Santa Clara County.

HOV lane conversion from the south San Mateo County border to Whipple Avenue will begin the week of March 18, 2019. Closures of select lanes will occur nightly between 9 p.m. and 5 a.m. (excluding Friday and Saturday nights). No daytime lane closures are anticipated. Over the next three months, construction activities will take place in Palo Alto, East Palo Alto, Menlo Park and Redwood City. During this time, construction activities will be limited to the shoulders and median of U.S. Highway 101. Work from Whipple Avenue to I-380 will then follow later in 2019. The entire project should be completed in 2022.

Construction activities include placing temporary concrete barriers, demolishing portions of the existing median barrier, removing pavement and installing temporary traffic monitoring equipment. Caltrans has constructed express lanes in other areas and found that noise associated with these activities was largely blocked by existing sound walls and is expected to cause only minor noise increases. Nighttime lighting will also be used, but lights will be pointed toward the roadway to minimize impacts to nearby residents. 

Key project benefits

• Encourage carpooling and transit use
• Improve travel time and reliability for express lane users
• Increase person throughput (the number of people moved)
• Use technology to manage traffic flows 
• Reduce congestion in the corridor
• Make upgrades to pavement and lane striping
  
  

During construction, every effort will be made to minimize impacts on existing traffic ?ow and neighboring communities. Nighttime work minimizes impacts during peak daytime periods. 

For more information, visit the San Mateo 101 Express Lanes Project webpage, where you can sign up to receive construction updates. You can also follow @CaltransD4 on Twitter.