BIRMINGHAM, Mich. – A first-of-its-kind pilot study based in Birmingham aims to reduce red light wait times in a big way.
How long a light stays red or green is based on traffic patterns, and that preset is usually updated every five to 10 years.
After an 18-month study and collecting data from 34 Birmingham intersections, the University of Michigan researchers discovered a way to update traffic signals more often while costing less.
The Road Commission for Oakland County partnered with researchers from U of M to see how they could improve traffic signal timing by using GPS data in General Motors vehicles. GM vehicles represent about 6% of vehicles on the road.
Researchers reprogrammed traffic lights, leading to a 20% to 30% decrease in the number of stops.
“This is kind of like the holy grail for traffic signal timing engineers,” said Craig Bryson, senior communications manager for the road commission. “This tells us how many cars there really are in each direction and allows that signal timing to be much more reflective of the actual traffic. So we’re making the system much more efficient, and when it’s more efficient, it’s safer because people aren’t taking a risk to try to go through a yellow light because they’re frustrated.”
It usually takes a lot of time and money for the county road commission to do that process every five to 10 years for every intersection.
“That requires having a staff person go and sit at the intersection and literally count cars for five hours a day, the morning peak, the evening peak, and off-peak time,” Bryson said.
He said that now the study will expand, and if the results continue to be promising, this process could be valuable for communities worldwide.