Three big rigs barrelled up and down the 110 Freeway on Wednesday, mirroring one another in a tight pattern.

Two of the Volvo big rigs bore special antennas to “talk” to one another and radar that can detect movement around them.

They were accelerating and navigating without human help.

It was only a test, but the partially automated trucks provided a peek into the future of long-haul trucking. The demonstration’s sponsors hope it provides a step toward completely automated transport in the years ahead.

“It’s smooth, safe and efficient,” said Carrie Brown, Caltrans’ district director for Los Angeles and Ventura counties.

The project is part of a collaboration between UC Berkeley Partners for Advanced Transportation Technology and Volvo Group of North America, sponsored by Caltrans and the U.S. Department of Transportation.

The idea: Demonstrate how the technology could reduce greenhouse gases, increase energy efficiency and heighten safety in the commercial transportation system.

Using what’s called “cooperative adaptive cruise control,” the heavy trucks drive tightly together, responding to one another and their surroundings with computerized sensors, saving fuel and releasing fewer emissions. Well-plotted trips would also ease congestion, experts believe.

“Simply put,” she said, “the trucks are driving as a stable unit.”

On the road

The first live display of automated truck platoons in Southern California appeared to roll without a hitch.

The demonstration stretched from the Los Angeles Port Headquarters to the 110 Freeway’s Sepulveda Boulevard exit and back again, about a 12-mile loop.

Stepping into the big rig was a group of four, including a reporter and California Highway Patrol accident investigators. They saw a truck that looked much like any other, except for cabins equipped with computer hardware, including a laptop and tablet wired to the dashboard.

“What we are going to do is show when we are on the freeway how good the system works and how responsive it is with cut-ins and cut-outs,” explained Aravind Kailas, a technology planner for Volvo, who served as the group’s guide.

The biggest benefit from platooning: When the front truck slows, the others follow suit, simultaneously. There’s no lag time — and that improves safety, Kailas said.

He displayed a tablet that showed the images of three truck outlines. Xiao Yun Lu, the driver of the third truck and a research engineer at Partners for Advanced Transportation Technology, pulled onto the 110 Freeway from Harbor Boulevard in San Pedro under a sunny blue sky.

A few moments later, an icon representing the third truck lit up on the monitor as the driver flicked on a sophisticated brand of cruise control.

The cabin shuddered a bit, but soon the ride turned smooth. The demo rolled on, seemingly without a hitch, no pun intended.

Within a few minutes, a car cut in between the second and third trucks.

The truck automatically decelerated, but Yun Lu eventually hit the brake pedal, disengaging the chain of 18-wheelers.

Lu’s action after the car’s intrusion triggered the system to disconnect and gave control back to the drivers, much like cruise control in your family sedan.

But soon the trucks gathered back into close formation, with a distance of about 1.5 seconds — about 50 feet — separating the big rigs. The rear truck’s speed will never exceed that of the lead vehicle, Kailas said.

The demo team acknowledged there are kinks to work out. For instance, the communication system needs to be protected from interference from outside systems, so the security needs to be shored up.

Experts believe it could take years for the technology to roll for real while federal officials work on standards.

Nonetheless, the test’s team members believed they proved there’s a future for such automation on the road.

“It’s promising,” said John Fasana, Metro Board chair, after his test ride.

“We have heard about adaptive cruise control for cars,” he said, “and it’s great to know we are looking at it for the ports as well.”