Toll express lanes help East Bay commuters to Silicon Valley jobs in N Calif

April 13, 2012

No news they say is good news. There's no news of problems three weeks after the start-up of Silicon Valley's first toll express lanes on state route 237 (CA237) and a stretch of I-880 - a project to eliminate a bottleneck at the interchange of the two expressways by allowing single occupant vehicles to buy into previously underused HOV lanes. It's a relatively modest project - just under $12 million - but it allows solo commuters to save up to six minutes at the 237/880 interchange by using a central direct connector bridge.

Previously the HOV lanes ran only 870 vehicles/lane average in the peak hour of the morning peak period and only 680 vehicles in the peak hour of the afternoon peak - showing that at the period of greatest demand they had serious unused capacity. (Lanes can flow freely carrying 1500 to 2200 vehicles/hour.)

Tolls came into effect March 20 (2012) to allow drivers previously ineligible by occupancy to use the lanes. Volumes of traffic are managed by variable pricing to maintain free flow for carpoolers, buses and tollpayers.

Objective of the dynamic price toll management is level of service LOS-D or better.

No reports yet of the actual extent of the improvements.

Peak AM flow in to the Valley

The peak flow in the morning is southbound on I-880 and westbound on CA237 for East Bay workers in the big employment centers of Sunnyvale, Mountain View, Los Altos and Cupertino, northern portions of Santa Clara county. And of course  in the evening the peak flow is the reverse - eastbound CA237, northbound I-880.

Initially the project was pretty much the interchange's central curving bridge ramp alone and that is still the centerpiece of the project but it has ended up an HOV-HOT lane conversion inbound starting on I-880 1.3 miles, 2km north of the interchange and extending west 4.7 miles, 8km to Lawrence Expressway. East and northbound the toll express lane is somewhat shorter starting further east on CA237 about 2.5 miles, 4km from the interchange and going the same distance northbound 1.3 miles, 2km on I-880.

At the ends the toll payers have to depart the express lanes which remain as HOV lanes. The  capital cost mainly consisted of the toll systems, new signage including variable message signs, and restriping plus the studies, design and outreach.


There were strong protests from the mayor and commuters in Milpitas just off the project.

In order to safely handle the greater traffic flow from toll buy-in the free entry and exit HOV lane with dashed striping was replaced by a double solid white striping. That was precisely to prevent weaving movements between the express lanes and near-Milpitas interchange ramps over that four 4 miles, 7km stretch of the two highways.

Engineers judged the purpose of the express lane conversion would defeated and safety endangered by allowing such intermediate entries and exits. Milpitas commuters should regain some of those losses through reduced traffic in the right-hand general purpose lanes.

TransCore the implementer for Valley authority VTA

The CA237/I-880 toll express lanes are a project of the Santa Clara Valley Transportation Authority (SCVTA) and Caltrans. Much of the expense of the project was a toll and traffic management system from TransCore who wrote the variable pricing algorithms, designed and supplied electronic toll  readers and license plate reading and traffic management cameras, traffic detection gear for HOT and GP lanes, as well as interfaces to the Bay Area Toll Authority for back office toll accounts and billing.

Funding was a mix of local monies and federal value pricing program grants.


Similar BATA/Caltrans toll express lanes have been in operation southbound-only since September 2010 on 14 miles, 22km of the I-680 parallel to the I-880 in Alameda County to the north and extending in to Santa Clara county.

VTA is working on much larger toll express lanes projects on the two major highways from the 'West Bay' or San Francisco direction, the CA85 and the US101. The CA237 lanes would probably then be extended west to US101, and I-680 TELs might be extended south to the US101. (see large map)

Major assessments and planning were done for VTA back in 2007-2008 by URS with Gray Bowen and Wilbur Smith Associates.  They proposed next:

-  a conversion of 24 miles of state route 85 (CA85) HOV lanes to 2x1 toll express lanes at a cost of about $96m ($72m of road improvement, $24m toll system/traffic management)

- followed by a much more elaborate US101 HOV-HOT conversion plus lane additions for 2x2 toll express lanes on 34 miles costing $416m ($367m civil work, $29m toll systems)

They forecast toll revenues of $42m by 2020 and $118m by 2030.

Santa Clara Valley Transportation Authority:

"Silicon Valley Express Lanes Program: Implementation Assessment and Plan Nov 2008 URS Gray Bowen WSA:"

"Just road pricing" by Lisa Schweitzer & Brian Taylor in ACCESS magazine Spring 2010:

ADDITION: Brandi Childress, PR for Santa Clara Valley Transportation Authority says that Express Lane use has steadily grown since opening, with the number of toll-paying customers increasing from around 1,300 to over 1,800 per day. Through the first 11 days of operation 18,000 solo drivers paid to use the express lanes.

Morning commuters traveling westbound on 237 have reported travel time savings of up to 16 minutes, when compared to drivers in the general purpose lane. There is preliminary data indicating  commuters in the general purpose lanes have benefited with travel time savings of up to 3 minutes, when compared to the travel times before the facility's double white solid striping was put in, apparently through reducing slow downs due to lane changes.

Tolls charged have ranged from a minimum of 30c up to a high of $4.75, with an average toll of $1.55, generating a total of $26,000 in the first weeks of operation.

VTA is continuing to monitor community feedback and provide information on how the facility works.  As the public becomes familiar with the new facility and has a chance to try it first-hand, there is increasing appreciation for the benefits of the new configuration, including the double white striping which reduces lanes changes and smoothes the traffic flow through the area between SR237/Calaveras Blvd and N. First Street.

"Some commuters have expressed disappointment with the new facility, particularly carpoolers from Calaveras Boulevard that now have to drive further to access the westbound Express Lane, and those solo motorists who used to jump into the HOV lane at 9am, that now have to wait for 10am to enter the lane when it becomes a general purpose lane open to all vehicles."

Childress says they've look into complaints from Milpitas carpoolers who are used to Calaveras Boulevard and it is true that they can take up to 4 minutes longer to get into the express lane, as compared to travel time before the conversion. She says the number of commuters negatively impacted by these changes at Calaveras Blvd is far outweighed by the overall travel time savings for all commuters in the general purpose and Express Lanes.

TOLLROADSnews 2012-04-12

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