Experts want to add a fourth light: White light to change traffic

Researchers at North Carolina State University are now proposing a radical new measure for traffic: a fourth traffic light in the color white.

The traffic light would be activated when enough autonomous cars are present at an intersection.

The white light will signal to human drivers to follow the autonomous cars in front of them.

According to the researchers, the autonomous cars will act as mobile traffic controllers.

They will coordinate movement through the intersection based on real-time data and traffic density.

The model is called “distributed coordination”, where the cars negotiate with each other on the most efficient direction and timing.

The new method is described in a scientific paper published by IEEE.

Large efficiency gains in simulated testing

In simulations, delays at intersections were reduced by between 3.2 and 94 percent, depending on how much of the traffic consisted of self-driving cars.

Overall efficiency was improved by up to 98.9 percent compared to traditional signals.

– The white signal utilizes the computing capabilities of self-driving cars, says Ali Hajbabaie, lead author of the study.

– It creates a new type of signal so that human drivers understand what to do. Red still means stop. Green means go. White means: Follow the car in front of you, he explains.

However, the concept requires a high level of autonomous traffic and a well-functioning digital network between cars.

At intersections with few or no autonomous cars, the classic red-yellow-green system will still be in use.

Long way to practical application

Although the results are promising, the researchers estimate that the technology is many years away.

Fully autonomous cars are not yet widespread and the infrastructure in most countries is lacking.

According to the study, three quarters of current traffic systems need to be either upgraded or replaced before the system can become a reality.

However, the proposal offers a glimpse of what future traffic with intelligent, autonomous vehicles could look like, and how a simple change in traffic signaling can significantly improve traffic flow.