California’s First Smart Highway Project Comes to Life

The state’s first full-fledged smart highway project, SMART Corridor, uses IoT, digital signs and active traffic management tools to reduce jammed sections of I-80 in the San Francisco Bay Area.

Drivers stuck in a very congested section of Interstate 80 in Emeryvillle, CA, and Berkeley, CA, finally got to see the state’s new freeway metering lights and digital signs come to life. Dubbed the Interstate 80 SMART (Safety, Mobility and Automated Real-time Traffic Management) Corridor project, the goal is to bring innovative congestion relief and safety improvements to the I-80 corridor from the Carquinez Bridge to the Bay Bridge, according to the California Department of Transportation (Caltrans). This section of I-80 carries approximately 290,000 vehicles a day and has on average one major incident a week.

Caltrans says the project is expected to reduce the impact of commute and incident-related congestion on that particular stretch of freeway, including long delays and stop-and-go traffic, congestion-related traffic collisions, long emergency response times, unreliable commute times and cut-through traffic.

Traffic flow improvements include adaptive ramp metering to smooth merging lanes and maintain consistent speeds. The metering lights were phased in over a three-week period. The state has also installed an array of digital signs at 11 locations along the initial 20-mile section. The digital signs include colored arrows and X’s, so drivers can quickly and easily know which lanes are flowing freely and which ones are blocked by an accident or other snarl.

The entire SMART Corridor project became operational in 2016. The $79 million project includes a broad set of components, IoT devices and traffic management tools. The plan includes:

• High occupancy vehicle (HOV) bypass lanes at ramp meters
• Active management of traffic during freeway incidents using variable advisory speed limits and lane management on the freeway and coordinated traffic signal timing on the local streets
• Bus priority at traffic signals and ramp meters
• Enhanced traveler information, including large roadside panels with travel-time information and other advisories, such as “construction ahead.”

Integrated IoT and Traffic Team

The coordinated operation of all of these components will be controlled by automated technology and a staff working in the traffic management center in downtown Oakland. The traffic staff will monitor sensors and cameras to help traffic flow.

One part of the project is to synchronize traffic lights on major city streets that motorists frequently route to when collisions jam I-80. Improvements on the local thoroughfare San Pablo Avenue and crossing arterials include “Trailblazer” digital signs to tell drivers who detour around an accident when to return to the interstate when the wreckage has been cleared. Signal timing improvements will also ease traffic flow and bus operations on San Pablo Avenue when traffic from the congested freeway spills over onto city streets.

Search the Twitter hashtag #80smart.