Early findings show adaptive traffic signals on Highway 68 speed up commutes.

As part of a five-year pilot project related to the Scenic Route 68 Corridor Improvements Project, Caltrans District 5 installed nine AI-driven adaptive traffic signals along Highway 68 between Salinas and Monterey, which went live on Monday, May 4, to optimize traffic flow by responding to real-time traffic patterns. 

An update about the performance of the signals, located between San Benancio Road and Josselyn Canyon Road, was provided by the Transportation Agency for Monterey County’s Principal Engineer Doug Blise to the agency’s board on Wednesday, May 27. He mentioned that the spring and fall are the best times to monitor traffic patterns, while schools are in session, and pointed out that the traffic signals have only been up for a short time. 

“Obviously, these are preliminary findings and this is a work in progress,” said Blise at the meeting. 

The early results showed an improvement in travel times during peak traffic times. During morning commute hours, the adaptive signals reduced westbound travel time from Salinas to the peninsula by more than four minutes, increasing the average speed from 19.5 to 21.6 miles per hour. In the afternoon hours, the AI lights reduced travel times in the eastbound direction by just under a minute, with average vehicle speed increased from 30.3 mph to 31.1 miles per hour.

Blise mentioned that increased traffic flow from the adaptive signals on 68 leads to traffic delays on the adjoining side streets, and that the adaptive lights can only do so much to improve commute times without increasing the roadway's capacity.

According to a statement from TAMC, the next optimal time to evaluate the adaptive signal’s performance is this fall, when school is back in session.

“There’s more analysis to come,” Blise said. “We’re not done with it yet.”