US 101 Express Lanes Project

 U.S. 101 Express Lanes Project

Silicon Valley produces between 20- 25% of California’s annual gross domestic product. This economic juggernaut has fueled revenue and job growth, but it has also created overcrowding on San Mateo Highway 101, the major commute route between San Francisco and Silicon Valley.

Why an Express Lane 

Caltrans studied many options before concluding that express lanes would be the most effective means of lessening congestion in the corridor.

When traffic engineers looked at building a typical lane, a lane with no restrictions on occupancy, they found – not surprisingly – that the new lane would be overused and congested the very day it opened. On the other hand, when they studied building a carpool lane, they found it would be underutilized, even during carpool hours.

Between these two choices, is the express lane option, which allows buses and carpools to travel free of charge while selling the excess capacity to drivers willing to pay a toll. When the toll-paying vehicles move into the express lane, they will lower congestion in the mixed flow lanes.

Carpoolers with 3 or more persons will always be exempt from tolls. All other things being equal, (traveling at the same time, through the same location) a vehicle with two passengers will pay a smaller toll than a single occupant vehicle. Traffic engineers have guidelines for predicting congestion based on traffic volumes.

The project will convert the existing northbound and southbound auxiliary lanes into through-lanes, and change the far left lanes into express lanes.

At Whipple Avenue, the new express lanes will connect with existing carpool lanes. Caltrans will convert these carpool lane into express lanes. The joining of express lanes will create two 22-mile long express lanes.

Construction on this $514 million project will begin in the winter of 2019 with an estimated completion of mid-2022. Project funding comes from a variety of sources including SB 1 funds.

More information on the project can be found at the project website:

Groundbreaking Ceremony – March 8, 2019

Photo Credit: San Mateo County Transportation Authority

Media Coverage Links:

ABC7 News

NBC Bay Area

KPIX Ch. 5

KRON Ch. 4

KTVU Ch. 2

Groundbreaking Handout

Construction Updates:

California Transportation Commission (CTC) Public Hearing:

The CTC will be holding a Public Hearing on Thursday, July 25, 2019 in advance of authorizing the San Mateo County Express Lanes Joint Powers Authority to operate an express lane.  Below is the hearing agenda:

San Mateo CTC Toll Hearing Agenda

CTC Application for the US 101 Express Lanes

Joint Exercise of Powers Agreement:

The Joint Exercise of Powers Agreement, entered into by the City/County Association of Governments and the San Mateo County Transportation Authority (Member Agencies), created the San Mateo County Express Lanes Joint Powers Authority. Below is the full text of the agreement:

Joint Exercise of Powers Agreement