Long-dormant metering lights at the end of the Interstate 80 on-ramps between the Carquinez Bridge and the Bay Bridge sparked to life this week, signaling the start of California’s first full-fledged smart highway project, which relies on gadgetry to speed traffic.

The metering lights, installed two years ago, were roused from their slumber before dawn on Tuesday, although the first of them won’t be operational until early next week. In the weeks to come, those mysterious dark electronic signs that hang over the Bay Area’s busiest freeway will also come alive.

Designed to help smooth merging and maintain traffic speeds, the metering lights will be phased in over a three-week period. They’re the first piece of the Smart 80 Corridor project, expected to be in full operation by Labor Day.

The $79 million project includes an array of overhead signs at 11 locations along the 20-mile stretch of westbound Interstate 80. The signs will include colored arrows and x’s to let drivers know which lanes are flowing freely or which are blocked by an accident, and other signs will suggest appropriate speeds. Large roadside panels will offer travel-time information and others will display advisories like “Construction ahead.”

Alternate routes

Another part of the project will synchronize traffic lights on major boulevards, like San Pablo Avenue, that motorists frequently take when collisions clog I-80. Signs and arrows will direct drivers back to the freeway once they’ve passed the crash site or the wreckage has been cleared.

The high-tech system will be controlled by both computers and a staff of humans working in the traffic management center in downtown Oakland, where they’ll monitor sensors and cameras. The goal, said Ivy Morrison, a project spokeswoman, is to make traffic flow better, especially during peak times. The freeway is consistently rated the Bay Area’s worst commute, carrying an average of 270,000 cars a day.

“It’s not going to make congestion disappear. We want to be clear about that,” Morrison said. “It will help better manage traffic flow and reduce the number of secondary accidents that happen because people don’t realize traffic has come to a stop ahead of them.”

Although the ramp metering lights were turned on Tuesday, they’ll remain green — “resting green, we call it,” said Caltrans spokeswoman Shannon Brinias — from 5 a.m. to 8 p.m. weekdays and then be turned off.

On Tuesday at 5 a.m., the lights in both directions will start metering traffic if it’s heavy enough, but only until noon. The lights will remain green from noon to 8 p.m. for another week. Then, on Aug. 2, they will be activated from noon until 8 p.m. as well. From then on, the lights will meter traffic on on-ramps from 5 a.m. to 8 p.m. on weekdays. Beginning July 30, the ramp meters will also operate on weekends when traffic grows sluggish.

Based on traffic

“Traffic conditions dictate if the metering lights are in use,” Brinias said. “If there’s no slowdown, we won’t have red lights preventing people from merging onto the freeway. Only when traffic reaches a certain level are they turned on.”

Caltrans anticipates backups at some on-ramps as drivers get used to the metering lights, but Morrison said the ramp meters include a feature that automatically turns the lights green when traffic starts to back up onto local streets. The I-80 meters are the Bay Area’s first with advanced technology to adapt to traffic levels.

Once the ramp meters are operating smoothly, probably within a couple of weeks, Caltrans will switch on the overhead signs. Next will come the roadside traffic information signs, and, finally, the signs on local streets directing drivers back to the freeway.

The project was supposed to start smartly moving traffic in 2015, but the challenges of getting cities, counties, transit agencies and technologies working together took longer than anticipated.

“It’s the most sophisticated system of its kind in the state of California,” Morrison said. “It’s a very ambitious project, and we want to get it right.”

Michael Cabanatuan is a San Francisco Chronicle staff writer. Email: mcabanatuan@sfchronicle.com Twitter: @ctuan