For nearly a century, the trio of red, yellow, and green has governed our intersections. These universally recognized signals have become so embedded in our daily lives that we rarely question their design. But researchers at North Carolina State University are challenging this standard with a groundbreaking proposal.
If the thought of a fourth color on the stoplight makes you scratch your head, then join us as we explore why some researchers believe we actually need an additional light.
The White Light Revolution
This isn’t simply an aesthetic change; it’s a response to the dawning age of autonomous vehicles (AVs) and represents a fundamental shift in how we might navigate intersections in the very near future. The white light would serve a unique purpose, unlike any of the existing signals.
When activated, it would indicate to human drivers that autonomous vehicles are temporarily controlling the traffic flow at that intersection. Drivers would simply need to follow the car ahead of them—if it stops, they stop; if it proceeds through the intersection, they follow.
Science Behind The Signal
Associate Professor Ali Hajbabaie and his team at North Carolina State University developed this concept through extensive computational modeling. According to their research published in IEEE Transactions on Intelligent Transportation Systems, incorporating this white phase could significantly reduce traffic delays, even when accounting for pedestrian movement through intersections…