Author: Salena Fitzgerald
A traffic light with a green arrow against an orange sky.

Ryan Jasper, a junior in the Department of Applied Mathematics and Statistics, has created a modeling technique that could help traffic engineers better adjust the timing and operations of left-turn signals at intersections, potentially improving traffic flow for vehicles trying to turn.

Unlike typical traffic engineering models based on assumptions about the frequency of cars arriving at the intersection in the opposite lane, Ryan Jasper’s model relies on different information: how long it takes for each car to make a complete left turn. This allows his model to understand the flow of traffic coming from the opposite direction without having to collect actual data on it.  Jasper will describe his approach at the Whiting School of Engineering’s annual Design Day on May 1.

“What makes our approach unconventional is that rather than making assumptions about the distribution of times it takes for cars to clear an intersection, we incorporated a random parameter linked to the preceding car’s time,” said Jasper, who was advised on the project by Fred Torcaso, a senior lecturer in the Department of Applied Mathematics and Statistics.

“This approach challenged conventional wisdom but yielded insights that could revolutionize traffic analysis.”

The student’s analysis found something unexpected: When only a few cars were waiting to turn left, the wait times for each car to make the turn varied wildly. But as more cars entered the queue, wait times for each to make the turn evened out to a consistent distribution.

“By understanding and optimizing left-turn wait times, not only can individual commuters experience smoother, more efficient journeys, but the collective efficiency of entire traffic networks can be greatly enhanced, offering tangible benefit,” said Jasper.