Traffic Signals Evolve: Driverless Cars May Bring White Light Addition to Century-Old System

Driverless cars are set to revolutionize more than just how we drive; they might also change how traffic signals operate. Researchers at the University of Michigan, led by civil engineering professor Henry Liu, are pioneering a new approach to traffic signal systems that could be closer to implementation than previously thought. In a pilot program in Birmingham, Michigan, they utilized data from General Motors vehicles to optimize traffic light timing, enhancing flow even with a limited percentage of connected vehicles.

This project, boosted by a recent U.S. Department of Transportation grant, relies on existing car-generated data instead of costly infrastructure overhauls. The results in Birmingham have already shown reduced congestion with minimal adjustments to green light timings.

In a parallel development, North Carolina State University’s Ali Hajbabaie is testing the addition of a fourth light—possibly white—to guide autonomous vehicles at intersections. This approach would signal autonomous vehicles to follow the lead car through intersections when active. Although implementation could be years away and would require a significant proportion of traffic to be autonomous, the concept aims to integrate seamlessly with current systems.

Despite these innovative approaches, some industry voices, like Waymo’s Sandy Karp, urge caution. They highlight the success of autonomous vehicles in environments without these adaptations and caution against premature infrastructure investments that might not be necessary as autonomous technologies evolve.