White Traffic Light

If you’re anything like me, maybe you share my frustration at traffic lights when drivers are sluggish to go on the green and slow to approach a green but then zoom through when it turns orange. We are imperfect beings, but perhaps more perfect are our smart vehicles. There’s a relatively new idea involving the introduction of a "fourth color" traffic light, specifically a white light, that has been proposed by researchers at North Carolina State University. This concept is designed to enhance traffic flow and efficiency, particularly in the context of increasing numbers of autonomous vehicles (AVs) on our roads.
​

​What, why, how, I hear you ask?

The "White Phase": The key idea is a "white phase" where autonomous vehicles effectively take temporary control of traffic management at an intersection. This system relies on AVs' ability to communicate wirelessly with each other and with the traffic signal system.

Signaling to Human Drivers: When enough AVs are detected approaching an intersection, the white light would illuminate. For human drivers, the instruction during this "white phase" is simple: "Follow the car in front of you." This means if the car ahead (which would ideally be an AV coordinating with the system) proceeds, you proceed; if it stops, you stop. The specific color "white" isn't strictly necessary, as long as the signal is clearly distinguishable and doesn't create confusion with existing red, yellow, or green meanings.

AV Coordination: During the white phase, the AVs themselves would coordinate their movements to optimize traffic flow through the intersection. They would essentially become "mobile traffic controllers," using their collective computing power and real-time data to make rapid, efficient decisions on who goes when. This distributed control aims to reduce delays, fuel consumption, and improve overall travel times for all vehicles, not just AVs.

Benefits for Mixed Traffic: The simulations conducted by the researchers show significant benefits even with a relatively low percentage of AVs on the road. For instance, delays dropped by 70% when 30% of vehicles were AVs, and even a 10% AV presence led to noticeable reductions in delays. This system is designed to work in "mixed traffic streams," where both human-driven and autonomous vehicles share the road.

Impact on Traditional Lights: When there aren't enough AVs to activate the white phase, or if the AV system is not active, the traditional red, yellow, and green traffic lights would function exactly as they do now. Red still means stop, green still means go.

What could possibly go wrong 🙂
​

Ep345

Image created by AI