Promoting the Adoption of Four-Color Traffic Signals

Get ready to embrace change if you’re accustomed to the traditional green, amber, and red traffic lights. Recent studies propose that incorporating a white light could enhance traffic flow and bolster safety for motorists and pedestrians alike.

Since the 1920s, the standard has been red for stop, green for go, and amber for prepare to stop (or speed up for some drivers). This convention is even upheld by an international treaty to prevent accidents resulting from drivers in one city misinterpreting signals in another.

Evolution of Traffic Technology

During the last hundred years, advancements in traffic technology have been ongoing. Semaphore signals have given way to electric lights, and computers have facilitated the synchronization of multiple lights along with the incorporation of sensors to study traffic patterns and adapt timings for better efficiency. Sophisticated systems have emerged to supervise traffic lights across entire urban areas, and researchers have refined digital representations of traffic behavior to achieve a remarkable level of accuracy.

The advent of autonomous vehicles (AVs) has introduced a new dimension. Unlike traditional vehicles treated as mere objects on a map, AVs possess the capability to drive themselves and communicate with each other and a central traffic management system.

Integration of Autonomous Vehicles (AVs) in Traffic Control

This implies that autonomous vehicles (AVs) become integrated into the traffic control system and can collaborate to significantly enhance traffic flow. A team of researchers associated with North Carolina State University proposed that once a substantial number of Autonomous Vehicles (AVs) populate the roads, they could introduce an additional traffic signal—signaled by a white light—alongside the customary trio. While their computer simulation effectively expedited traffic flow through intersections, there was still room for improvement.

Ali Hajbabaie on the Introduction of the ‘White Phase’ Traffic Signal

Ali Hajbabaie, an associate professor of civil, construction, and environmental engineering at North Carolina State University, explains, “Our previous research introduced the concept of a fourth traffic signal, known as a ‘white phase,’ which leverages the computational capabilities of autonomous vehicles to streamline traffic at intersections. However, we had not yet considered the implications of this concept for pedestrians. We have now expanded our computational modeling to include pedestrian traffic, and the results show great promise for both pedestrians and vehicles.”

Similar to the earlier study, AVs guide human-driven vehicles in their lanes. When a sufficient number of AVs are present, the signal switches to white, instructing human drivers to follow the AV or the vehicle in front of them. With more AVs, traffic flow accelerates. The key difference now is the inclusion of pedestrians in the model.

Despite pedestrian traffic, the team found that overall traffic flow improved by over 25 percent for both vehicles and pedestrians.

Challenges in Implementing Enhanced Traffic Control System with Autonomous Vehicles

However, several challenges must be addressed before implementing such a system. Achieving a critical mass of AVs on the roads is essential, as is installing an adequate number of four-light signals. Additionally, gaining the trust of human drivers in the new white signal and making signals understandable to pedestrians, possibly through blinking green lights or clearer indicators, present further obstacles.

“We are currently establishing a physical testbed to experiment with this concept in real-world conditions, rather than solely relying on computer models,” Hajbabaie explained. “However, the vehicles in our testbed are small-scale, allowing us to identify implementation challenges without the cost and safety risks associated with full-scale vehicles. In the meantime, we are open to collaborating with industry and research partners to explore avenues for advancing these technologies.”

The broader question remains: how to integrate the new light into the familiar signals we teach children. The traditional song may require revision: “Stop at the yellow light, go when it’s green. Wait for the yellow light, a pause in between.” However, incorporating the white light instruction could be more complex: “Follow the autonomous car ahead, or cross the road if you wish, or simply wait, as advised by the white.” It’s evident that refinement is necessary.

Read the original article on: New Atlas

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