101 Transit Corridor

Highway 101 is the main transport corridor on the SF Peninsula, yet it is congested during peak hours. Rather than to add lanes and simply increase vehicle capacity, there should be a reevaluation of Highway 101 to make it an intermodal corridor.

With continued ridership growth for the past 10 years, Caltrain is approaching its capacity. Even with electrification and other improvements, which will greatly increase Caltrain’s capacity, there’s still a need to develop a secondary regional transit corridor to…

  1. Make transit more competitive in areas outside the immediate Caltrain corridor.
  2. Encourage smart growth in areas outside the Caltrain corridor.
  3. Complement Caltrain service

Highway 101 was a transit corridor since the 1940s with regional and intercity buses (from NorCal Express Newsletter published in 2011) :

“The remaining routes operated by Greyhound on the peninsula were the B, C, F, G, H, K, L, M, and Z. The coast routes were the N, O, and S. The B route ran between the San Francisco depot on 7th Street and the Redwood City depot. The C and the F route ran from the SF depot to the depot in San Jose. The two routes ran express on the Highway 101 freeway to Ralston Ave in Belmont where it exited the freeway. The C and the F routes then made stops at all of the cities between Belmont and San Jose. After the stop in Palo Alto the C route continued on Alma Ave making depot stops in Mountain View and Sunnyvale. The F route continued on the El Camino Real bypassing the depots in Mountain View and Sunnyvale. The routes joined up again at Fairoaks and El Camino Real in Sunnyvale continuing on the El Camino Real to San Jose. The M route ran between the depot in SF to San Mateo. The B, C, F, and M were the main peninsula commute routes and ran almost 24/7. The G, H, K, L, and Z were routes that ran between the SF depot and Redwood City and Palo Alto mainly during commute hours only.”

These routes were transferred to Santa Clara County Transit (renamed VTA in 1997) and SamTrans a few years after their formation. Many of the routes shifted their focus to local service and end their routes at the county line.  SamTrans continued to operate a more extensive network of express buses in San Mateo County via 101 until 2009 when the economic downturn forced the agency to discontinue express bus service except route KX. Many impacted commuters were told to take Caltrain or BART as alternatives.

Today, besides route KX, the 101 corridor is used by many corporate commute shuttle buses, along with buses to the East Bay that operate on a short portion of 101.

Making 101 more transit friendly

HOV/HOT lanes can help speed up transit service and can even provide operating subsidies with toll revenues, regardless of which option is chosen (new HOV/HOT lanes, conversion of existing lanes to HOV/HOT). However, in order to provide frequent service, special center on-freeway transit stops and/or dedicated HOV on/off ramps are needed, which increase costs beyond just adding or converting lanes.

An alternative to dedicated HOV/HOT on/off ramps is to allow buses on freeway shoulders. This allows on-freeway stops to be located on the side. Buses would only be permitted to use shoulders when the freeway is congested, and buses must travel at a speed no higher than 35 mph. HOV/HOT lanes can be implemented in addition with buses on shoulders. This allows longer distance non-stop buses to use HOV/HOT lanes, and all-stop buses (as well as buses entering or exiting) to bypass traffic with shoulder lanes. This offsets the lack of dedicated HOV on/off ramps.

Video about the Bus on shoulder system of Triangle Transit in Durham, NC.

Examples of on highway transit with side on-freeway stops

Golden Gate Transit – US 101 is the main transit corridor for Golden Gate Transit buses between North Bay cities and San Francisco. Local route 70 serves all freeway stops in Marin County. Express route 101 between Santa Rosa and San Francisco makes limited stops in Marin County and takes advantage of the HOV lanes in Marin County.

Denver/Boulder RTD Flatiron Flyer – Besides an aggressive rail expansion program in the region, part of the Fastrack plan is to provide enhanced bus service along the US-36 corridor. The corridor will have on-freeway bus stops on the side. Buses will be permitted on freeway shoulders and will also utilize center HOT lanes.

What could 101 transit corridor look like

The corridor would consisted of all-day basic service in addition to express routes.

Stops (* – existing stops):

  • Millbrae Transit Center*
  • Broadway
  • San Mateo/3rd Ave*
  • Hillsdale* (currently unused)
  • Ralston
  • San Carlos
  • Whipple
  • Marsh
  • Willow
  • University
  • Embarcadero/Oregon
  • Rengstorff
  • Ellis
  • Fair Oaks
  • Bowers
  • 1st Street at Metro/Airport*
  • Downtown San Jose
  • San Jose Diridon Station*

This corridor serves a variety of commute demands with different origins and destinations depending on travel directions (* – existing routes):

All day service (Red) Millbrae – San Jose (All stops)
Northbound AM/Southbound PM (green) -SF commuter routes is a restoration of SamTrans routes that were discontinued in 2009. These commuter routes provide alternative to overcrowded Caltrain. Foster City – SF
San Mateo – SF
Millbrae – SSF/Oyster Point*
Millbrae – Sierra Point*
East San Jose/Berryessa BART – Stanford
Southbound AM/Northbound PM (blue) -Each route stops at Millbrae and the last on freeway stop before exiting. These stops allow passengers to transfer to rail and all-stop buses.There would be multiple routing in SF including Van Ness, 19th Ave, Cesar Chavez/Mission.
Each destination does not need to have a route from each corridors in SF. The system is designed that passengers can transfer at Millbrae or at another on freeway stop.
SF & Millbrae – Lockheed/Sunnyvale
SF & Millbrae  – Montague/North 1st St
SF & Millbrae  – Stanford Business Park
SSF Ferry – Millbrae
Millbrae – North Foster City*
Millbrae – Redwood Shores
SF & Millbrae – Menlo Park Bayfront
SF & Millbrae – Mountain View/North Shoreline

Clipper cards will be the primary method to pay for bus fares. The fares and fare structure would be compatible with Caltrain so this would be in a way an expansion of the Caltrain system (via bus).

How to fund the service

Because of the regional nature of the service, the three counties can use the Caltrain JPB’s structure to provide funding for the service. Since JPB is housed in an agency that also manages buses, JPB is capable to either operate, or procure a private or public operator to provide such service.

There are some current and past examples where regional bus service is provided under regional funding and partnership

  • Dumbarton Express – Jointly funded by BART, VTA, SamTrans, AC Transit, Union City Transit, and operated by contractor MV Transportation.
  • Sound Transit (Seattle) – Regional express bus service funded by Sound Transit is operated by local transit agencies in the Seattle area.

Although this is not meant to be a wholesale replacement of the various shuttle programs offered by different companies, the private sector should have the ability to buy into this system rather than providing shuttles on their own. Caltrain offers GoPass program that allows corporate buy-ins. Stanford also pays AC Transit for the U line in exchange for free access for their employees.

Station amenities


Rail like system map for buses on Harbor Transitway in Los Angeles.

On freeway stops, along with major transit centers like Millbrae, should provide rail like experience for passengers. There should be a rail-like system maps showing bus destinations, along with real-time bus info.

On freeway stops should have shelter, lighting, and safe access from the streets. Stops should include facilities such as pick up/drop off area, bicycle parking, and automobile parking. Real-time bus arrival displays should be available from the streets in addition to the platform. Many of the stops along the freeway BRT corridors like Flatiron Flyer in Denver and I-15 in San Diego have access features similar to rail stations like Caltrain and BART. These stations require substantial investments beyond just simple HOV lanes.

Under this plan, Millbrae is designated as a primary transfer point because of proximity to 101, numerous bus bays, and direct connection to BART and Caltrain. As a start to such system, perhaps SamTrans should encourage private commuter buses to make use of the under-utilized Millbrae Transit Center to facilitate rail-to-bus or bus-to-bus transfers.

Fare and service integration/coordination

In the past when 101 corridor had more frequent transit service, the bus companies operate in competition with Southern Pacific which operated commuter rail service. The distinct branding (and apparent competition) between bus and rail continued under public ownership.

The distinct branding and fare structure seems to wasteful and inefficient, and make transit inconvenient overall. For example, riders who have a bus pass have to pay full fare to take Caltrain, and riders who have a Caltrain pass have to pay full fare on express bus. Current fare payment technology can allow fare to be properly credited to the service without a complicated system of paper transfers. For example, an efficient system should allow a single fare for passengers taking Caltrain from 4th & King to Millbrae, and transfer to a 101 bus to Redwood Shores area. The system should also allow passengers who normally take the 101 bus during peak hours to take Caltrain at night without additional fare.

In the Seattle area, the Sounder commuter rail only operates during weekday peak hours primarily in peak direction. Off-peak and weekend service is covered by express bus service along the corridor (which also serve stops outside the rail corridor). Between Tacoma and Downtown Seattle, Sounder runs 8 trains during the morning commute hours between 4:55am and 8:00am, with trains running as frequent as every 20 minutes. Also from Tacoma, buses run every 5 minutes during morning commute hours to downtown Seattle, and every 20 – 30 minutes at other times.

On the Peninsula, buses can provide additional capacity beyond what Caltrain can provide. During off-peak hours, at night in particular, buses can fill the service gap left by Caltrain. Although there’s demand for more Caltrain service during off-peak hours, work window must to made available for various construction projects along the corridor, along with accommodating freight trains.