Traffic lights have maintained the same three colors for over a century, but there is now a proposal to introduce a fourth color aimed at managing the flow of traffic, particularly around autonomous vehicles (AVs). While fully driverless cars are not yet widely operational, companies like Waymo are nearing the SAE Level 4 automation milestone, with Tesla and other AVs gaining popularity.
Although UK roads currently restrict self-driving vehicles to limited trials, the Automated Vehicles Act could permit broader use by 2026. This will likely lead to a mix of human-driven cars and autonomous vehicles sharing the roads in the near future.
Engineers at North Carolina State University have proposed a ‘white light’ system for traffic lights to facilitate the integration of human-driven cars and driverless vehicles. This system aims to enhance traffic flow by allowing autonomous vehicles (AVs) to assist and provide situational awareness to human drivers.
Dr. Ali Hajbabaie, the study lead, suggested that the white light phase would leverage AVs’ computational capabilities to track vehicle positions. While red and green lights would still indicate stop and go, respectively, white lights would signal human drivers to follow the lead of the vehicle ahead, thereby improving overall traffic coordination.
Dr. Hajbabaie and his team introduced a new traffic light system in the journal of Computer-Aided Civil and Infrastructure Engineering that incorporates a white light to indicate coordinated movements among autonomous vehicles (AVs) at intersections.
This system enables AVs to communicate wirelessly with each other and with traffic signals. The activation of the white light by AVs and traffic signal computers allows non-autonomous vehicles to follow the lead vehicle. Computer simulations illustrated the functionality of the proposed system, which would continue to use traditional red, yellow, and green lights for regular traffic when AVs are not prevalent.