Coming soon: Less traffic with a smart Interstate 80

When the I-80 Smart Corridor Project is completed in late 2015, motorists will see signs telling them about the traffic flow before them. Photo:  Smart Corridor Project
When the I-80 Smart Corridor Project is completed in late 2015, motorists will see signs telling them about the traffic flow before them. Photo: Smart Corridor Project

Motorists driving south on Interstate 80 near Gilman might have been surprised recently by a new sign with flashing “Xs,” yellow and green arrows, or a “30” or “55.”

The sign is part of the I-80 Smart Corridor Project, an ambitious and technologically advanced $79 million endeavor to smooth the travel of the 270,000 cars that traverse from the Carquinez Bridge to the Bay Bridge each day.

That stretch of road is frequently regarded as the worst in the Bay Area. Driving the eight miles from Richmond to Emeryville can take as little as 20 minutes or more than an hour, according to transportation planners.

To alleviate that congestion, Caltrans, along with local county transportation agencies, is constructing a network of integrated electronic gantries that will provide real time traffic information that has been collected by sensors and cameras on the freeway and nearby roads. In addition, Caltrans is adding 44 metered on-ramps and signs on auxiliary streets like San Pablo Avenue.


I 80 Smart CorridorWhen the project is completed later this year, drivers will get warnings about the state of the traffic flow in front of them. The 11 signs that will stretch  across I-80 (part of the 200 electronic signs in the project) will have a grid for each lane of traffic. The intent is to have a green “X” when traffic is flowing smoothly and at the speed limit, a red “X” when traffic is stopped ahead, or a yellow arrow to suggest motorists switch lanes. The grids will also be able to tell drivers how fast the traffic in each lane is moving.

“The signs that you have noticed near Gilman are elements of the SMART Corridor project on I-80,” Ivy Morrison, a public information officer for the I-80 Smart Corridor Project, wrote in an email. “These overhead signs, which are currently being tested, will light up when there is an upcoming accident or traffic jam, and provide real-time information to motorists. The signs can provide traffic information (such as ‘Accident Ahead’), indicate which lanes are closed so that merging can happen in advance of the accident, and encourage motorists to follow an advisory speed limit based on road conditions. These signs are one part of this effort to improve safety and reliability along I-80 from Richmond to Emeryville.”

The I-80 Smart Corridor Project will also extend beyond the freeway to San Pablo Avenue. Now, when there is an accident on Interstate 80, motorists often get off to use San Pablo as an alternative route because they don’t know where the accident is. Then they stay on San Pablo for a long time because they are not sure when they have passed the accident, said Morrison. That causes congestion.

The Smart Corridor Project will install “trailblazer signs” along San Pablo to tell motorists when they have passed an accident, said Morrison. The project will also enable Caltrans to synchronize the street’s traffic lights when there is an accident, which should make traffic flow more smoothly, she said.

“In the event of an incident on the mainline (I-80) resulting in heavy traffic volume on San Pablo & local streets, Caltrans will coordinate the local traffic signals to flush traffic through more quickly,” said Morrison. “Local traffic will be given signal priority (e.g. longer green lights).”

Testing started early this summer on the software that runs the integrated signs, said Morrison. It should be completed by November or December. Until then, motorists might see the signs lit up, accompanied by the word “Test.”


The sponsors of the I-80 Smart Corridor Project include Caltrans, the Federal Highway Administration, the Alameda County Transportation Commission, the Contra Costa Transportation Authority, and the West Contra Costa Transportation Advisory Committee.

The funds for the $79 million project are coming from the Corridor Mobility Improvement Account (CMIA) created by State Proposition 1B, approved by Californians in 2006 for transportation needs, as well as from Alameda County Transportation Commission’s Measure B half-cent sales tax and Contra Costa Transportation Authority’s Measure J half-cent sales tax.

A breakdown of the funding for the I 80 Smart Corridor Project. Photo courtesy of Smart Corridor Project.
A breakdown of the funding for the I 80 Smart Corridor Project. Photo courtesy of Smart Corridor Project.

Watch this three-minute video for a description of the project:

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