What is the reason why a 'fourth color' may be added to future traffic lights?

General automobile traffic lights have three colors of `` red, yellow, and blue (green) '', but research by Ali Hajbabaie et al., Associate Professor of Civil Engineering, Construction and Environmental Engineering at North Carolina State University The team has announced research results that adding a new 'fourth color' to traffic lights may make traffic smoother.

White Phase Intersection Control Through Distributed Coordination: A Mobile Controller Paradigm in a Mixed Traffic Stream | IEEE Journals & Magazine | IEEE Xplore


Researchers Propose a Fourth Light on Traffic Signals – For Self-Driving Cars | NC State News

Traffic Lights Could Have a 4th Color in The Future. Here's Why. : ScienceAlert

In recent years, the practical application of self-driving cars has been promoted mainly in the United States, and it is expected that the proportion of self-driving cars running on general roads will increase in the future. Automated driving cars not only reduce the burden on drivers and avoid accidents due to human error, but are also expected to have the advantage of alleviating traffic congestion by reducing ``unnecessary braking'' by humans.

Research that traffic congestion is reduced just by mixing several automatic driving cars on the road - GIGAZINE

by gscruton

Hajbabaie and others advocate the concept of 'white phase' in which an automatic driving car communicates with surrounding automatic driving cars and traffic light control computers to realize smooth traffic. During the white phase, self-driving cars can use their computing power to efficiently and intelligently adjust traffic flow to select the optimal road selection and driving speed. However, it will take time for all cars to become self-driving cars, and in reality, a certain number of human-driven cars will continue to exist for a long time.

Therefore, Hajbabaie and colleagues advocate the idea of adding a fourth ``white light'' to the traffic light to let the human driver know that the automatic driving car running around is actually managing traffic. . ``The red light still means 'stop,' the green light means 'go,' and the white light tells the human driver to 'follow the car in front,'' said Hajbabaie. I will.”

Below is a diagram that actually incorporates the ``fourth color light'' into the traffic light. Black cars represent self-driving cars, and white cars represent cars driven by human drivers. People in automatic driving cars do not need to see the lights of traffic lights, but human drivers look at the white lights and judge that they should go to the car in front. When the number of automatic driving cars passing through the intersection falls below the threshold, the traffic light will switch to the usual `` red / yellow / blue '' light. The research team uses ``white light'' for convenience, but it does not necessarily have to be white because it is OK as long as the difference from the existing light is known.

A traffic simulation model used by the research team showed that self-driving cars improve traffic flow with or without a white phase that controls traffic by communicating with the surroundings. When the white phase was introduced, traffic became even smoother, and fuel consumption was reduced by reducing unnecessary stops and starts. In addition, the higher the percentage of intersections with white lights, the faster the speed through the intersection and the less fuel consumption. Hajbabaie claims that in the white phase, 10% self-driving cars reduced delays by 3%, and 30% self-driving cars reduced delays by 10.7%.

“Granting a portion of traffic control to self-driving cars is a relatively new idea called the mobile control paradigm,” said Hajbabaie. “It can be used to coordinate traffic in any scenario involving self-driving cars. 'But we think it's important to incorporate the concept of white lights at intersections to let human drivers know what's going on and what to do when they're approaching an intersection.' said.

At the time of writing the article, there is no mechanism implemented to control the traffic volume by communicating with the automatic driving car and the control computer of the traffic light, and it takes a long time and a lot of money to update the traffic light. However, Hajbabaie argued that a white phase pilot program could be implemented on roads around ports where there is a high proportion of commercial vehicles and traffic flow is important. ``Commercial vehicles appear to have a high adoption rate for autonomous vehicles, so there is an opportunity to conduct pilot programs that could benefit port traffic and commercial shipping in this environment,'' he commented.

in Ride,   Science, Posted by log1h_ik