CAPAC, MI – Interstate 69 west of this small town 58 miles (93 km) north of Detroit is straight, flat, smooth and lightly traveled – a perfect location for one of the nation’s first public highway tests of communication between vehicles and imbedded signals alongside the road.

This ability to talk to each other is deemed a vital link on the path to autonomous vehicles that automakers, government entities and high-tech outfits such as Google and Apple are vigorously pursuing.

The I-69 test included four line-haul Class 8-plus-size military trucks operated by the U.S Army’s Tank Automotive Development Center (TARDEC) based in Warren, MI, and 20 roadside radio signals installed by the Michigan Department of Transportation over approximately seven miles (11 km).

A TARDEC spokesman says the test was concluded without a hitch. ”It went as planned…it went well,” he says.

The sand-colored military trucks are described as “semi-autonomous” because of the wide range of advanced technology they carry, including radar, cameras, computers, sensors and actuators, all developed to one day attain driverless capability.

Drivers were at the wheel in the I-69 project, however, which aimed to test reliable Direct Short-Range Communication (DCRC) between the vehicles and the MDOT sites that can alert them about traffic, rest areas, bridge clearances, closed lanes, speed limits, obstacles such as disabled vehicles, awareness of nearby police and EMS vehicles and much more.

“You can download all of the messages you need to know and get an early warning,” TARDEC Chief Roboticist Robert W. Sadowski says.

TARDEC’s ultimate goal is autonomous operation of many of the scores of vehicles under its jurisdiction in a program it calls Autonomous Mobility Applique System (AMAS). That technology remains in development and was not demonstrated in the I-69 test, but the radio link between vehicles and roadway signals supports the AMAS mission.

Longer term, TARDEC seeks to develop platooning of supply vehicles with a driver only in the lead truck and all others trailing behind operating sans drivers. Clearly, advance knowledge of road conditions would be mandatory.

Sadowski says TARDEC has installed devices at the rear of test trailers to enable platooning by controlling spacing, especially at night when only very limited LED lighting is used to avoid detection. Laser radar is installed up front to visually discern potential hazards, although cost remains a challenge, he says.

TARDEC Director Paul D. Rogers describes the test as a “win-win” for the Army and MDOT, because it provided both with valuable experience as standards are promulgated covering driverless vehicles. Until now TARDEC has conducted most of its testing on military bases, away from public traffic.

Asked about the threat to cybersecurity as autonomous vehicles take hold, Rogers says TARDEC is addressing “the risk of vulnerability” to such incursions “and how to mitigate them.” Similar efforts are under way by numerous other organizations.

MDOT Director Kirk Steudle says Michigan will have installed roadside communication sites covering 380 miles (612 km) of interstate freeways by 2018, describing it as “the largest testbed in the U.S.” MDOT also is working with commercial-vehicle fleets for future testing, he adds.

Steudle says safety is paramount in the move toward driverless cars and trucks, underscoring that “980 people were killed on Michigan highways in 2015. I think that eventually we can eliminate 80% of those crashes” as technology takes the wheel.