Ten Lane Widening Planned for Highway 101 in San Mateo County

San Mateo County officials are desperate to widen Highway 101 from eight to ten lanes at a cost of over $300 million. Photo: Andrew Boone
San Mateo County officials are desperate to widen Highway 101 from eight to ten lanes at a cost of over $300 million. Photo: Andrew Boone

Still seeking to widen Highway 101 from eight to ten lanes, Caltrans and San Mateo County’s transportation agencies are now halfway through the required environmental review. At a community meeting on Wednesday evening, agency officials gave an update on the project [PDF] to widen the highway by adding express lanes, which allow buses and carpools for free but charge a fee to solo drivers during congested hours.  

“The goal here is to make a consistent travel time for carpools and buses,” said San Mateo County Transportation Authority (SMCTA) Deputy Project Manager Leo Scott at the meeting. “If we can do that, we incentivize the movement from single occupancy cars to higher occupancy vehicles.”

But at the same time, widening the highway to ten lanes does exactly the opposite, creating more space for more single occupancy vehicles – Caltrans is expecting the number of vehicles on Highway 101 to jump from between 4 and 7 percent in just the next three years. Most of Scott’s presentation addressed how ten through lanes can be squeezed into the limited space available, a strong hint that county and state officials favor widening the highway rather than addressing congestion by providing better bus and carpool services.

“An auxiliary lane begins and ends at on and off ramps, it doesn’t go through… we actually will literally pave through the interchange and connect the auxiliary lanes to create a through lane,” explained Scott. “We are actually looking at re-aligning the freeway, taking the center line and moving it, typically to the west, and what that allows us to do is create more width.”

Highway 101 could be widened to ten lanes by converting existing auxiliary lanes to through lanes. Some shoulders and auxiliary lanes would disappear. Image: Caltrans
Highway 101 could be widened to ten lanes by converting existing auxiliary lanes to through lanes. Some shoulders and auxiliary lanes would disappear. Image: Caltrans

Caltrans officials are at least allowing an option that would avoid widening the highway but still provide increased capacity by converting an existing lane in each direction to an express lane to be studied the project’s environmental impact report, although the focus of the planning work so far indicates they aren’t serious about that option.

“Most of the presentation focused on challenges related to physically widening Highway 101 – shifting lanes and relocating sound walls,” said TransForm Senior Community Planner Chris Lepe after the meeting. “Scant attention is being paid to the major increases in bus and carpool use that are needed to make the [express] lane conversion option work.”

Converting existing lanes to express lanes rather than widening Highway 101 would save about $200 million, money that could be spent on boosting SamTrans’s bus service, further Caltrain upgrades beyond electrification, and other transportation demand management programs in San Mateo County. But officials were silent at the meeting on the details of how transit could help alleviate traffic congestion, or how to pay for better transit, only stating that a separate study of highway bus service had just begun.

Community meeting on Highway 101 expansion in San Mateo. Photo: Andrew Boone
Community meeting on Highway 101 expansion in San Mateo. Photo: Andrew Boone

In 2010 SamTrans eliminated nine of its ten express bus routes that comprised an entire network of public transit on Highway 101. These routes ran between San Francisco and Pacifica, Colma, Foster City, San Mateo, Redwood City, San Carlos, and Palo Alto during weekday commute hours. Given the prospect of continuously free-flowing express lanes on the highway, the agency is now reconsidering its decision to kill off its highway bus service. But even SamTrans doesn’t have high hopes, estimating that express buses would only contribute roughly one quarter of the mode shift from automobiles to buses that’s needed for the lane conversion option to provide as much total passenger capacity as widening the highway.

“The one promising thing that’s working in our favor is the reverse commute,” said SamTrans Director of Planning Douglas Kim, referring to the increasing numbers of workers who live in San Francisco and commute to workplaces in San Mateo and Santa Clara counties. This trend means robust ridership for highway buses to and from San Francisco during both the morning and evening commute periods.

But officials are skeptical that any additional revenue will be available to pay for express highway buses.

“How would the tolls revenues be used?” asked Scott. “First it’s going to cover any financing, then it would go to pay for the operating and maintenance of the facility, and then the revenue would be available for transit in the corridor.”

No other sources of revenue for better bus service or other transportation demand management programs has been identified. Money for widening the highway has better prospects, and could be paid for using the San Mateo County Transportation Authority’s Measure A, the recently passed California Senate Bill 1, and/or other state funds.

San Francisco and Santa Clara counties are also pushing ahead with studies to add express lanes to Highway 101, that if constructed would stretch from downtown San Francisco to Morgan Hill, completing a major segment of the Metropolitan Transportation Commission’s network of envisioned Bay Area Express Lanes.

The current $11.5 million environmental impact report for express lanes on Highway 101 in San Mateo County is expected to be finished in January 2018. Caltrans will host a second community meeting on the project this Monday, June 5 at 6:30 pm at Redwood City City Hall, 1071 Middlefield Road, Redwood City.

  • xc ❄

    It’s a bummer to hear they’re widening … but from my understanding conversion to HOV lanes is more difficult (legally / red-tape) than widening.

    Also, I don’t love the idea that someone can pay to ride in the express lane … so many rich folks are going to take advantage of that probably.

  • 94110

    Andrew, any idea whether this is being studied for impacts on VMT (Vehicle Miles Traveled), or if it is considering LOS (Level of Service)?

    I’m confused about whether California law requires one or the other at present, and whether this depends on when a project started.

  • Davey43

    But if you charge them appropriately, then the county gets the money (which, considering their lack of foresight to apply the funds for more meaningful TDM projects, makes little sense).

  • jonobate

    I am perfectly fine with taking the money of rich people who want to save a few minutes on their commute and using it to fund transportation.

  • xc ❄

    Oh sure! I’m definitely for that … I just hope it doesn’t clog the lane!

  • xplosneer

    State law says it can’t go below 45, and if it does they have to go to “Carpool only.”

    That just needs to be studied and enforced.

  • jonobate

    Nah, they raise the prices once the lane starts getting clogged. As a result, less people choose to pay for the express lane, congestion goes down, revenue stays the same or increases.

  • jonobate

    If moving more people within a limited ROW is the goal, why aren’t we considering rail in the median of the US-101? If we can add two travel lanes, we can add two rail tracks instead.

    SPUR suggested this concept in their Caltrain corridor study: http://www.spur.org/sites/default/files/publications_pdfs/Appendix_D_Rail_Concepts_for_the_Future.pdf

    I’d add that BART would be a good option for this route, given that it’s currently planned to terminate at Santa Clara Caltrain. You could route it north from there up to US-101 and then northeast to Google-land, connecting back to Caltrain at Redwood City.

  • thielges

    Rail in the center makes the most sense long term however will cost significantly more than $200M. This is one of the ways that freeway upgrades receive the lion’s share of transportation funding. Each incremental upgrade is relatively “cheap”: $50M here, $200M there, a couple of $100M interchange upgrades, etc. These smaller projects fly under the radar unlike the Caltrain electrification project that attracted a lot of attention. It is putting a band-aid on a band-aid approach to building out infrastructure.

    I wonder how much Caltrans D4 has spent on the 101 corridor between SJ and SF over the past two decades. That info is hard to find but is probably in the billions.

  • gb52

    Come on. Again and again, AND AGAIN, widening does not work. We’ve seen it over and over that projects like the widening of the I-405 in LA did not reduce traffic but increased the number of drivers which then further exacerbated local traffic and created a larger demand for a limited parking supply. Widening 101 will not make traffic better, nor will it move people faster. We’re building our way to LA traffic while LA is actually building more transit. We should implement the express lanes and restart bus service. And if you want to think out of the box, why not add new train service instead?

  • gb52

    One additional thing to note, is you’ll see that in the photo for the article how wide freeway lanes are and how drivers are not able to center vehicles in their lane. At some point we will be able to reduce freeway lane widths and drive closer together using autonomous features like adaptive cruise control and lane centering. But what’s amazing is that we already have all this technology for trains and could implement it now instead of waiting decades for all older vehicles to become equipped with these technologies. (And guess what, autonomous cars can only work if everyone attempts to follow the rules. It cant stop a non-autonomous vehicle from cutting you off or crashing into you!)

  • Jeffrey Baker

    It kinda seems like they could try something more incremental, like extending carpool hours (to 24×7 if needed), raising the carpool size from 2 to 3, etc. Carpool hours currently end at 9AM and 7PM but anybody can tell you that traffic is still utterly befucked at those times.

  • dat

    I can’t wait! As soon as the additional lanes open, more drivers can spread out and two new lanes to drive slowly in. #occupypassinglane

  • Andy Chow

    and where are you going to put the stations?

  • Andy Chow

    The problem with even a lane conversion is that it is not zero construction as it seems. With traffic moving at different speeds, you need space for barrier or buffer so that HOV/HOT traffic can move in and out safely. It isn’t so much of a problem with new lane construction because the new lane adds capacity, which reduces the speed difference between HOV and non HOV lanes.

  • The problem is that no carpool lane exists in most of the project area.

  • Which is why we need to support alternative 3: convert an existing general purpose lane to an express lane, allowing free access for buses and carpools (of either 2 or 3+ people). It’s the cheapest alternative, but the one motorists most likely will oppose.

  • As Andrew explained in the article, express lane revenues are used for: “First it’s going to cover any financing, then it would go to pay for the operating and maintenance of the facility, and then the revenue would be available for transit in the corridor.”

  • Ultimately the ‘answer’ is to use the freeway to move more people without increasing the number of vehicles, meaning getting people into transit and carpools. An express lane does just that, allowing single-occupant-vehicles access, at a cost, to use the lane when space capacity exists, but then freezing them out when it doesn’t.

    Andrew wrote that the agencies appear more intent on adding a lane rather than converting an existing lane, which I think is what all Streetsblog readers should support.

    Funny, what’s cheapest here (lane conversion) is also what’s best!

  • jonobate

    You might be able to locate stations in places where the freeway could be widened to accommodate the platforms. If not, the stations could be elevated above the freeway, and supported using straddle bents.

  • jonobate

    Just as one example… there’s a good 300m space on the north side of US-101, centered on Permanente Creek trail, where you could locate a North Bayshore station. BART platforms are around 200m long. You’d need to partially take a couple of Google parking lots, but no buildings.


  • Bernard Finucane

    They should just narrow the lanes to 10 ft, remove the median shoulder and add a lane from the extra space. Set the speed limit to 35 mph. If congestion is an issue 35 is fine.

  • 94110

    Not having had my question answered, I went to the meeting. The answer seems to be that both are required at this point–VMT for CEQA and LOS for NEPA.

    Also, I think that VMT (and LOS) may have to be calculated for nearby intersections. Caltrans is saying they are hearing from local stakeholders along El Camino Real that traffic is spilling over from 101 because of congestion. Depending on metrics, this might (I’m inferring) cause the option which adds the most lanes to 101 to look the best for VMT.

    It will be an interesting EIR.

    I think the “no build” option may be my preferred choice at this point. Even option 3 (which doesn’t add any lane miles) will require large tolling signs retrofitted onto the center divider.

    Seems like the kind of thing that could be best solved with some thermoplastic and a few HOV LANE signs.

  • KJ

    Yes, but instead of BART, Caltrain express route or HSR bypass.

  • Jeffrey Baker

    Indeed, but why are the hours so short when the lanes do exist? The “express lane” on 880S at SR-237 ends at 10AM while traffic is still catastrophic. If it is supposed to be a demand-responsive pricing regime it doesn’t make sense to hard-wire the hour at which it ends.

  • keenplanner

    This is just crazy. TransForm did a comprehensive study of the alternatives and converting a lane was clearly the best option.

  • keenplanner

    True, and many of the 2+ carpool lanes in San Mateo and Santa Clara Counties are violating FHWA regulations which demand that carpool lanes travel at a minimum of 45mph, 90% of the time. They must also boot out the “clean air” vehicles if the lanes are congested, and, finally, the HOT lane drivers, but this will never happen because of the revenue. Priority should be moving buses and 3+ carpools.
    These counties and Caltrans don’t have the pair to do this as they fear more congestion in the GP lanes.

  • San Mateo County officials are desperate to widen Highway 101 from eight to ten lanes at a cost of over $300 million. Photo: Andrew Boone


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