NASHVILLE, Tenn. (WTVF) — A first-of-its-kind open road testbed is now live on Interstate 24.
It’s the only one like it in the country. The Tennessee Department of Transportation expects it to bring researchers, car-makers and tech companies to Nashville to test the future of transportation in a real-world environment.
The first experiment is happening this week during the morning commute. Researchers from the CIRCLES Consortium, which includes Vanderbilt University, have joined forces with Nissan, Toyota and GM to equip 100 cars with technology to try to make traffic better. They’re hitting the road between 5 a.m. and 10:30 am, dispersed among regular commuters.
Each car is equipped with adaptive cruise control, a feature that automatically slows the vehicle when it senses other traffic slowing. It’s not uncommon on new models. But the experimental feature goes one step further, also using AI to communicate between the vehicles.
“Every once in a while (during the experiment) a vehicle is one of ours. Then these vehicles are going to turn on their automatic cruise control which, instead of doing what it would do if you buy it straight out of the factory, does something more. It coordinates with other vehicles to smooth traffic,” said engineering and computer science professor Alexandre Bayen, who is with the University of California-Berkeley. “What we want to show is that this coordination enables overall better traffic flow.”
They think it could be a game changer in reducing frustrating phantom traffic jams, where cars stop and go for seemingly no reason.
“The intuitive approach humans take is as soon as there’s a gap in front of them, they speed up to try to catch up. And it turns out this very normal reaction creates a lot of instability in traffic, and that’s the source of a lot of stop and go and essentially energy inefficiency,” Bayen said.
Around 175,000 cars pass through Antioch on I-24 any given day, according to TDOT.
“What we’re trying to do is demonstrate that even with a small proportion of such vehicles we can make things better for everybody,” said Bayen.
The theory was successful during a closed-track analysis by the same researchers. A single vehicle equipped with the technology was able to smooth out traffic in a field of 20 cars.
“We can't necessarily eliminate traffic congestion, but what we're trying to do is make it more reliable,” said Dan Work, engineer and computer science professor at Vanderbilt University.
Proving it on a real interstate is the ultimate test. That’s where the I-24 Motion testbed comes in.
The testbed consists of a four-mile stretch along the larger I-24 SMART Corridor between Murfreesboro and South Nashville. It is located in Antioch, from just south of Old Hickory Boulevard to just north of Bell Road, and is now equipped with 40 poles and 276 cameras that use AI to track the flow of traffic and collect real world data. No license plate information is taken.
“You can call it an MRI for traffic,” said Lee Smith, TDOT director of Traffic Operations. “Because you can see vehicle by vehicle, lane by lane, however traffic is reacting to whatever stimulus you put in there.”
Smith says the stretch in Antioch was selected because it is the area’s most congested. It also experiences the highest number and most severe crashes.
“It’s the worst traffic problem, so we want to put the resources there to solve that problem,” he said.
The final cameras went online around a week ago. And TDOT believes the cruise control experiment is just the beginning. Researchers can now measure how human behavior interacts with technology on an actual highway. And offering real-world traffic analysis at this scale is something that’s unique to Nashville.
“Any vendor, supplier, automaker, traffic simulation company that would like to come in and test their widget, their technology, autonomous vehicle, connected vehicle, a new traffic control strategy, we welcome them, Smith said.
Groups wanting to test their tech will have to apply. And the feature they’re testing must be road legal to operate.
This week, drivers may notice the Nissan Rogues, Toyota Rav 4s and Cadillac XT5s participating. They are each labeled with a brightly colored number, but otherwise look like any other vehicle. There are volunteer drivers behind the wheel, possibly helping make the commute a little smoother.
Researchers hope to have initial findings as early as Friday afternoon.
