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Project Information

Project location map

The San Mateo County Transportation Authority (SMCTA) and City/County Association of Governments of San Mateo County (C/CAG), as the project sponsors, propose to add a managed lane in each direction of U.S. 101 between the U.S. 101/I-380 interchange in South San Francisco and the San Mateo/San Francisco County Line.


Unlike a mixed-use lane where any vehicle can use the lane at any time, a managed lane has a set of rules about who can use the lane and when. Examples of managed lanes include high-occupancy vehicle (HOV) lanes (i.e. carpool lanes) and high-occupancy toll (HOT) lanes (i.e. express lanes).

The Project limits would extend approximately half a mile north of the San Mateo/San Francisco County Line to allow for pavement, signage, lighting, and utility installation. Depending on the alternative chosen, the Project may include modifying existing structures and possibly installing new civil infrastructure to support the operation of the managed lanes. 


Project partners are considering a range of alternatives including the addition of a new managed lane (Lane Add), or conversion of an existing lane into a managed lane (Lane Convert).

 Project Purpose

The project is intended to:

  • Increase person throughput (the number of people moved) and overall mobility on the corridor;

  • Encourage carpooling and transit use;

  • Improve travel time savings and reliability for managed lane users;

  • Provide continuity/connectivity with the express lanes south of I-380 to maximize travel time savings along the corridor; and,

  • Minimize operational degradation (worsening traffic conditions) of the mixed-use lanes.

 Project Schedule

The proposed schedule is as follows:

  • Project Approval and Environmental Review: November 2024

  • Engineering Design: December 2026

  • Right-of-Way: December 2026

  • Construction: December 2028

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