Driverless Cars Could Change Traffic Systems

The proliferation of autonomous vehicles (AVs) could drive a significant change in traditional traffic light systems, with projects suggesting using AV data to adjust traffic lights and even deploying a new white light to signal AV control over intersections.

North Carolina State University researchers have proposed a new white light system to enable AVs to control traffic flow and direct human drivers. 

Under the proposed system, connected cars could communicate with one another and with traffic lights. 

The white lights would illuminate to indicate the AVs are coordinating with one another to ease traffic flow and human drivers would then know to follow the car in front.

The team said the system would only be activated when there are more AVs on a road than human-operated cars, with the traditional traffic light system taking over again when human drivers outnumber connected cars.

In simulations, the team said the system was found to improve travel time and reduce fuel consumption.  

“This concept…taps into the computing power of AVs themselves,” said Ali Hajbabaie, study author. “Red lights will still mean stop. Green lights will still mean go. And white lights will tell human drivers to simply follow the car in front of them.”

Another project, from the University of Michigan, uses speed and location data from connected vehicles to time traffic lights. 

Related:Smart Cars Successfully Communicate With Traffic Lights in Public Test

The novel system uses vehicle trajectories to predict and adjust traffic light controls, using this data to create optimization algorithms for intersections identified as having “optimality gaps.”

In a pilot study in the Detroit suburb of Birmingham, the system reduced the delay and number of stops at signalized intersections by up to 20% and 30%, respectively.

The research responds to the need to optimize traffic systems, as a “cost-effective method for reducing congestion and energy consumption in urban areas”, without requiring changes to physical road infrastructure. 

The team said the new system could be applied to “every fixed-time signalized intersection in the world.”

While these systems would not be practical until there are more AVs on the road, increased investment and interest in similar projects indicate companies will be ready for infrastructure overhaul once AVs become commonplace.