San Mateo County Express Lanes Joint Power Authority

The management and operation of the Express Lanes is governed by the San Mateo County Express Lanes Joint Powers Authority (SMCEL JPA), a six member joint powers authority consisting of three San Mateo County Transportation Authority (SMCTA) Board members and three City/County Association of Governments of San Mateo County (C/CAG) Board members.  Additional information about our Board members and meeting material can be found here.

SM 101 Express Lanes Project Overview

The SM101 Express Lanes project constructed Express Lanes on US 101 in San Mateo County via a partnership between Caltrans, the SMCTA, and C/CAG. The project was constructed in two phases. The first phase, where the existing HOV lanes were converted into Express Lanes from the San Mateo County/Santa Clara County line to Whipple Avenue in Redwood City, was completed and began operations in February 2022. The second phase, where Caltrans constructed an additional lane on northbound and southbound US 101 from Whipple Avenue to I-380 in South San Francisco and converted the far left lanes to Express Lanes, was completed and began operations in March 2023. Following completion, the project was awarded the Envision Silver Sustainability Award by the Institute for Sustainable Infrastructure. 

Ultimately, this project created 22 miles of Express Lanes in San Mateo County and provided a seamless connection to the Express Lanes in Santa Clara County.


Limits of San Mateo Express Lanes on US Highway 101 between Santa Clara County and Interstate-380.


Additional project information can be found on the Caltrans website.  

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 modern technology to manage traffic
  • Reduce congestion in the corridor
  • Make upgrades to pavement and lane striping
Project Budget
 Fund Source  Amount* (in millions)
 SMCTA Local Measure A  $30.50
 Private Contributions  $53.00
 Federal  $9.50
 State  $306.67
 Regional  $95.00
 Future Toll Revenue (loan funding)  $86.47
Total  $581.14
*Includes environmental, design, right of way and construction phases