Metro Detroit Tests AI Traffic System That Cuts Delays by 20% at Lower Cost

University of Michigan researchers installed traffic signal timing technology at 13 metro Detroit intersections. The tech uses artificial intelligence and vehicle GPS data to reduce congestion. Installation occurred along 8 Mile and 12 Mile Roads, with expansion to 40 intersections planned within months.

Four signals along 8 Mile Road showed a 30% drop in delays. Stops decreased 40%. Nine signals along 12 Mile Road—from Vinsetta Boulevard to North Connecticut Avenue in Royal Oak—brought a 20% reduction in delays and stops.

The technology gathers GPS data from 5% to 10% of vehicles. Sources include roadside assistance systems, navigation apps, and rideshare companies like Lyft and Uber. Individual trips aren't tracked, protecting privacy.

"Vehicle telematics data provides us with opportunities that were previously unavailable to evaluate traffic signal timing performance across entire traffic networks," said Zachary Jerome, a postdoctoral research fellow at the Transportation Research Institute, according to a UM news release. "It enables us to proactively pinpoint inefficiencies rather than having to install roadside detection systems at every intersection."

Craig Bryson works as senior communications manager for the Road Commission in Oakland County. He explained that retiming signals required intense labor and substantial money. His agency could update timing once every five to 10 years. Many counties and municipalities never retimed their lights.

"Traditionally, it was labor intensive and expensive, so it didn't get done that often," Bryson said per Michigan Public. "It's very flawed because human beings, you know, get tired and they miss cars."

The new system costs about $2,500 per intersection per year. Current optimization costs run $4,000 to $5,000. Adaptive traffic signals using pressure plates and real-time reprogramming can cost as much as $50,000 per intersection.

"This will help us identify intersections where there is congestion and delay," said Danielle Deneau, traffic safety department director of the Oakland County Road Commission, as reported by the Detroit Free Press. "We can correlate or compare that to intersections where there are high frequencies of crashes."

The test ran 18 months at 34 intersections in Birmingham during 2023, bringing a 20% to 30% decrease in traffic stops. Researchers plan to test the system at 4,000 intersections across southeast Michigan next.

A $1.4 million Department of Transportation grant funds the project. The equipment will be sold by a startup called Connected Traffic Intelligence. Researchers and the institution hold a financial interest in the company.