Researchers in Europe are working on a concept that will be familiar to anyone who has seen films about the bands of travellers who settled the American West.
They are developing an electronic communications system that enables a wagon train of articulated trucks and cars to make semi-autonomous road trips possible - without the complexity of efforts like Google's driverless vehicles.
The makers of Volvo cars and trucks call the idea "platooning" and see it as a bridge to driverless cars.
The controls of following vehicles are wirelessly linked to a lead vehicle. Actions, like emergency braking, occur simultaneously, allowing the following vehicles to travel together much closer together than with a human at the controls.
Erik Coelingh, senior technical leader for safety and driver support technology at Volvo Car in Sweden, said his group participated last year in successful tests involving an articulated truck that led a second truck and three cars on European tracks and roads. The tests were part of the Safe Road Trains for the Environment project financed by the European Commission.
Drivers in vehicles outfitted with radar and laser systems that inform the adaptive cruise control, emergency braking and lane-departure systems, as well as video cameras, pulled in behind a moving articulated truck. After getting the leader's permission, the cars and truck linked wirelessly, and computers took over.
While the lead truck driver guided them, drivers in the following vehicles - each less than four metres apart - relinquished control.
Fuel economy increased 10 per cent to 20 per cent, according to participants, because airflow behind a long, tapered shape creates less turbulence.
Asked about the system's commercial viability, Coelingh did not mince his words, saying: "We're not there yet." He added it could be a decade before platooning became a reality.
Volvo's platoon research involves mostly existing technology as well vehicle-to-vehicle computer communication. Installing that equipment in a new vehicle today, Coelingh said, would add about US$5,300 to the vehicle's price.