Purdue invents technology to make traffic at intersections safer | News
WEST LAFAYETTE — An invention from Purdue University and the Indiana Department of Transportation is using wireless communication at traffic intersections, which could potentially save lives.
Senior Research Analyst Howell Li and Transportation Research Engineer Jijo Mathew of Purdue University’s Lyles School of Civil Engineering Joint Transportation Research Program have collaborated with INDOT to further improve the safety of vehicles approaching a signalized intersection, according to a statement from Purdue.
“According to the Federal Highway Administration, 2 million crashes occur each year at intersections with traffic lights,” the statement said, “resulting in hundreds of thousands of injuries and more than 3,000 deaths.”
Mathew said drivers’ decision to stop or continue at a traffic light is made once the light has turned yellow. Once drivers reach the “dilemma zone” when approaching an intersection, drivers cannot safely stop or safely clear the intersection at its current speed.
“To reduce accidents, the key idea is to provide protection against dilemma zones,” Mathew said in the release. “You would think that the yellow time can be extended; however, drivers tend to adapt to this, which reduces the likelihood of stopping.
“The state of the practice for powered intersections – intersections where the timing is influenced by sensors – is to use green extensions, where the green time is extended for a period when a vehicle is present. Although this reduces exposure of vehicles until the appearance of yellow, it can only last for a while.”
This Purdue-INDOT technology can extend green time or indicate yellow time as needed to keep intersections safe on a 0.1 second basis, according to the release.
The system considers each vehicle’s trajectory relative to a predetermined time when the green would end, the release states. If there is enough reserve time, the green will be extended until the vehicles leave the intersection.
If there are other vehicles competing for green time on other moves, the system will indicate yellow early before the vehicle enters the dilemma zone to allow for a safe stop.
Li said in the article that this innovation improves on traditional technology that extends green light signals in several ways.
“Infrastructure sensors have a fixed range, are expensive, can require intrusive installation on existing infrastructure, and require routine maintenance to ensure proper operation,” Li said. “And most sensors don’t detect vehicles continuously a mile away to adjust timing changes, such as when the onset of yellow occurs.”
Purdue lists a YouTube video in the article that features Li explaining in more detail how this technology works.
A wireless communication device is placed at traffic lights and in vehicles, and specialized control logic at the signal controller brings it all together, the statement said.
“Vehicles are already rolling off the assembly lines with integrated communication devices in the form of cellular,” Li said. adopted in the country and around the world.
“Compelling use cases such as reducing amber and red light incursions for heavy vehicles and supporting safety data for the results will accelerate adoption by transportation agencies, I believe.”
This technology was tested for a week on County Road 500 S. at US Highway 231 in Tippecanoe County. The remaining data for the benefit estimate was simulated.
“During my time working at the Indiana Department of Transportation, I only came across conceptual use cases involving in-vehicle in-vehicle communication technology incorporating live traffic light control,” said Tom. Platte of the Indiana Department of Transportation. “Our new technology moves this integration beyond mere concept. This work provides an implemented real-world use case that addresses an important security issue, among other applications.”
Margaret Christopherson writes for the (Lafayette) Journal and Courier.