Skip to Main Content Skip to Side Navigation Skip to Top Navigation
Community Outreach Photo

Contact Me

Community Outreach

(408) 321-7575

Home>Projects and Programs>US 101 Auxiliary Lanes

US 101 Auxiliary Lanes

U.S. 101 Auxiliary Lanes Project map



The project will construct auxiliary lanes in each direction of a 3.2-mile segment of U.S. 101 between State Route 85 in Mountain View and Embarcadero Road in Palo Alto.


The purpose of this project is to relieve existing and future traffic congestion along U.S. 101 between State Route 85 in Mountain View and Embarcadero Road in Palo Alto, and to improve safety along the U.S. 101 corridor in Santa Clara County by eliminating bottlenecks while providing additional capacity for vehicles to merge.

Project Features

The proposed improvements would:

  • Construct auxiliary lanes between on-ramps and off-ramps
  • Extend existing high-occupancy-vehicle (HOV) Lanes
  • Widen and modify on-ramps and off-ramps at each interchange to improve efficiency of the auxiliary lanes  
  • Improve traffic operations on the freeway by providing more room for traffic entering and exiting the freeway at each interchange
  • Allow traffic traveling from one interchange to the next interchange to use the freeway without impacting the main through lanes

Maintenance of Traffic Flow

For the safety of the public and construction workers, traffic control measures (such as temporary lane closures and detours) will be used as needed. Contractors will be required to make every effort to maintain access and minimize disruptions. The public will be notified before traffic control measures are implemented.


Upon completion, Caltrans will operate and maintain the highway improvements.

Capital Cost / Project Funding

$72 million: $56 million in Corridor Mobility Improvement Account (CMIA) Funds, $16 million in VTA Local Program Reserve Funds.

Project Schedule


2007-2009 Environmental Studies
2009-2011 Design and Engineering
Spring 2012 Begin Construction 
Summer 2014

Complete Construction