SM 101 - Managed Lanes Project (MLP)

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Public Comment Period for Revised Sections of the Report | July 10 – August 9, 2018

The California Department of Transportation (Caltrans) is recirculating portions of the Draft Environmental Impact Report/Environmental Assessment (DEIR/EA) for the Highway 101 Managed Lanes Project. The original version of the DEIR/EA was released on November 20, 2017, commencing a public comment period lasting through January 19, 2018

Since that time, Caltrans has revised portions of the DEIR/EA involving greenhouse gas, water quality and alternatives considered and eliminated. As such, Caltrans will open a new comment period, allowing the public to comment on the revised sections of the document. The new comment period runs from July 10 through August 9, 2018. Only comments addressing the revised portion of the DEIR/EA will be considered.

  • Download the Recirculated Partial DEIR/EA
  • To comment on the Recirculated Partial DEIR/EA use this link:

  • Hard copies are available for review at the Caltrans District 4 Offices
    M-F 8:00 AM - 5:00 PM
    111 Grand Avenue, Oakland 94623

    The Recirculated Partial DEIR/EA is available to the public at the following locations:

    • Caltrans District 4, 111 Grand Avenue, Oakland, CA 94612
    • City of Palo Alto Library, Rinconada Branch, 1213 Newell Road, Palo Alto, CA 94303
    • City of South San Francisco Library, Grand Avenue Branch, 306 Walnut Avenue, South San Francisco, CA 94080
    • City of Millbrae Library, 1 Library Avenue, Millbrae, CA 94030
    • City of Burlingame Main Library, 480 Primrose Road, Burlingame, CA 94010
    • City of San Mateo, Marina Branch, 1530 Susan Court, San Mateo, CA 94403
    • City of Foster City Library, 1000 East Hillsdale Boulevard, Foster City, CA 94404
    • City of Belmont Library, 1110 Alameda De Las Pulgas, Belmont CA 94002
    • City of San Carlos Library, 610 Elm Street, San Carlos, CA 94070
    • City of Redwood City Downtown Library, 1044 Middlefield Road, Redwood City, CA 94063
    • City of Menlo Park, Belle Haven Branch Library, 413 Ivy Drive, Menlo Park, CA 94025
    • East Palo Alto Library, 2415 University Avenue, East Palo Alto, CA 94303

    ML Map

    Getting More Passengers though the Busy Corridor

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

    The rush hour starts earlier and ends later. Travel times have increased while predictablity has decreased. A diabled vehicle at peak hour can create a ripple effect can last for minutes or hours, depending on the speed in which a tow truck can weave throught the backup.

    The impacts are economic as well as social. More time commuting means less time being productive at work and fewer hours relaxing at home.

    Getting people out of their cars and onto transit has helped, but it’s difficult to promote bus riding when a major incentive is lacking. Highway 101 in San Mateo County has no carpool lane. Buses and carpoolers must ply the same congested lanes as solo drivers.

    Shifting traffic patterns have exaserbated congestion. More workers are choosing to live in San Francisco, making a long trip to work and back each day. When motorists drive longer distances, it adds traffic to each bottleneck along the way.

    A Solution for an Urban Corridor

    Widening projects in urban corridors are fraught with expensive and time-consuming right of way problems. Anyone living on the peninsula for a long time knows that Highway 101 has been widened many times. The question is whether there is any more space for a widening project? It’s an important question because acquiring large swaths of property for freeway expansion is out of the question. The price of real estate in San Mateo County is far too expensive and the process of eminent domain is far too time consuming.

    Caltrans engineers found a solution by shifting centerline of the freeway, threading it through the right of way and keeping the shoulders within Caltrans-owned land. A six-foot strips of frontage road will need to be acquired, but that’s all.

    The widening won’t be typical. The plans require removing striping and reconfiguring lanes. But the time savings of eliminating right of way issues will be enormous, taking years off the project. Construction is due to begin in May 2019 with the project finishing two year later.


    How will this be done?
    • Connect all auxiliary lanes in San Mateo County, converting them into through-lanes.
    • Construct new auxiliary lanes where they are needed.
    • Convert the HOV lanes from Whipple Avenue to Matadero Creek into Express Lanes
    • Build a tolling system that uses FasTrak to collect tolls
    Why an Express Lane

    One of the best solutions to congestion is to focus on passenger throughput, not vehicle throughput. That would involve HOV or HOT Lanes, collectively known as managed lanes.

    Traffic engineers decided that the best solution for this corridor would be an express lane, where the toll operators could adjusting the price of travel according to congestion and the number of occupants per vehicle.

    Managing the Express Lane

    Traffic engineers have guidelines* for predicting congestion based on traffic volumes. Caltrans looks for a traffic volume of between 1600-1650 vehicles per hour to keep congestion from occurring in the managed lane.

    Proposed hours of operations are 5 am – 8 pm.

    Tolls will be adjusted as if by a dial. When congestion occurs, tolls will be “dialed up” which would mean that Single Occupant Vehicles (SOV) pay a toll and HOVs with 2 persons pay a reduced toll

    Carpoolers with 3 or more persons will be exempt from tolls. SOVs will always pay a higher toll than a carpooler with one passenger. But tolls will vary according to the congestion level. The point is to keep traffic flowing at 45 mph or faster within the express lanes

    *Other factors besides traffic volumes can create congestion: weather, accidents, debris in the road, etc.

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    Related Reading:

    Silicon Valley Express Lanes:

    San Francisco Transportation Authority Study of Carpool and Express Lanes:

    Project Links

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