Volvo has put its connective technology to the test with a three-truck convoy on a 12-mile stretch of California’s busy 110 Freeway using the European maker’s new ‘platoon’ concept.

Held last week, the trial was a joint venture between Volvo Group North America and the California Department of Transportation and saw the three trucks spaced 15 metres apart with two of the vehicles controlled using sensors and computers with a driver there to intervene if needed.

The platoon technology allows tightly contained, digitally connected packs of two to five trucks to drive in formation to reduce wind resistance and increase fuel efficiency.

The pack can be controlled by a “captain” in the cab of the front vehicle, with the rest following with their own drivers or eventually, autonomously.

“If you’re comfortable with the driver in front of you, it’s no problem,” said Mike Lackey, a U.C. Berkeley equipment driver.

Lackey sat at the controls of the second truck in the convoy but left them untouched except for guiding his Volvo rig onto streets and back to the freeway at the turnaround point of the 12- mile test.

Once he set the separation distance between the lead truck, software took over to automatically hold the position. If the lead truck drifted ahead, Lackey’s Volvo accelerated. When the truck in front slowed, Lackey’s braked.

“It does take a little getting used to,” Lackey said.

At the test speed of 55 mph, the driver can choose from four following distances, ranging from 0.6 seconds to 1.5 seconds behind.

According to a principal at Cambridge Systematics, which helped develop the adaptive cruise control system, the adoption of the technology could double the industry’s efficiency rate.

“Our technology planning and traffic simulation work suggests connected vehicle and truck platooning technologies may eventually facilitate the ability to operate up to 50 percent more trucks on these lanes – essentially giving the capacity equivalent of a third lane of freeway in each direction,” said Mark Jensen.

Trucking industry professionals see platooning as the first step in the roll-out of self-driving trucks and say it will lead to increased road safety and a reduction in emissions on America’s busiest routes.

“Through the use of vehicle-to-vehicle communication, platooning reduces the reaction time for braking and aerodynamic drag between vehicles, thereby improving safety and fuel economy,” said Susan Alt, a Volvo spokeswoman.

“California faces some of the worst traffic congestion in the nation, a contributing factor in the state’s air quality problems.”

Engineers at Volvo said that their platooning technology is an automated feature that can be disengaged and since driver input is needed, platooning does not make the truck an autonomous vehicle.