Transportation engineers at North Carolina State University propose a fourth light at traffic lights, called the “white light,” to improve traffic flow and reduce fuel consumption. The white light concept uses the computing power of autonomous vehicles (AVs) and involves a new traffic signal for human drivers. The researchers have conducted computational simulations and found the approach to be efficient and effective.

White Light Concept

The concept requires AVs to communicate wirelessly with each other and with the computer controlling the white traffic signal. If a certain number of AVs reach the intersection, the white light is activated and signals to humans that AVs will control the traffic flow. If there are too few AVs, the traffic lights work conventionally. The white light concept is part of a larger concept called the “mobile control paradigm”

Distributed Computing Approach

The team’s white light concept has improved from a centralized computing approach to a distributed computing approach. The distributed computing approach uses the computing resources of all AVs to dictate the traffic flow. The researchers tested the performance of the distributed computing approach using microscopic traffic simulators.

Simulation Results

The simulations show that AVs improve traffic flow and reduce fuel consumption, regardless of the presence of the white light. The simulations also show that the white light further improves traffic flow and reduces fuel consumption as the percentage of AVs increases. Even with just 10% of AVs at a white phase intersection, there are fewer delays and improved traffic flow.

Adoption of the White Light Concept

The researchers acknowledge that AVs are not ready for the distributed computing approach yet and that governments are not likely to install new traffic lights in the near future. However, the researchers believe there are elements of the white light concept that could be adopted with minor modifications to both intersections and AVs. The researchers suggest testing the approach at specific locations, such as ports, where there is a high volume of commercial vehicle traffic.

Conclusion

The white light concept is a promising approach to improving traffic flow and reducing fuel consumption, especially with the increasing use of AVs. Further research and development are needed to fully realize the potential of the white light concept and the mobile control paradigm.