Sep 2 2020
A new study proposes that the addition of only a few autonomous vehicles (AVs) on the road can make traffic flow safer, greener, and faster in the future.
A transition from mixed traffic containing human-driven vehicles (red) along with a small number of AVs (green) to self-organized constellations of AVs. Image Credit: Bar-Ilan University.
The focus of the study, which was published in the Journal of Physics A: Mathematical and Theoretical, was on the expected hybrid traffic flow of the future, which will merge conventional, human-operated vehicles with a small fraction of AVs.
This scenario leads to many questions regarding whether traffic flow would really get better and, if so, how many AVs would be needed to bring about considerable change.
It might look as if a huge number of AVs are needed for achieving a considerable effect on traffic flow, particularly on multilane freeways, because human drivers can just neglect and bypass AVs. However, this is not essentially so.
As part of the study, Dr. Amir Goldental and Prof. Ido Kanter, from the Department of Physics at Bar-Ilan University, propose a simple set of guidelines and regulations that help realize the self-organization of AVs into constellations that achieve dynamic regulation of the complete traffic flow.
The team recommends guidelines for efficient regulations that will help AVs to cooperate and considerably improve traffic flow even when less than 5% of the vehicles on the road are autonomous, as observed in the image provided above.
In the study, the team explains how AVs should act on a freeway to self-organize into groups that divide the traffic flow into manageable clusters. It was found that it takes less than 2 minutes to realize self-organized high-speed, greener, and safer traffic flow while beginning from crowded traffic.
Without regulations on AVs, we face a classic example of game theory paradox, such as the prisoner's dilemma, where each vehicle tries to optimize its driving speed but the overall traffic flow is not optimal. In our research we examine how, with proper regulations, a very small number of AVs can improve the overall traffic flow significantly, through cooperation.
Dr Amir Goldental, Professor, Department of Physics, Bar-Ilan University
In quantitative terms, the researchers report a significant increase in the traffic flow speed of up to 40% with a reduction in fuel consumption of up to 28%. Moreover, traffic safety improves as traffic becomes more organized and lane transitions decrease.
The study demonstrates that such enhancements can be realized without the need for a central agent that regulates AVs and without communication between AVs utilizing the present infrastructure.
Journal Reference
Goldental, A & Kanter, I (2020) A minority of self-organizing autonomous vehicles significantly increase freeway traffic flow. Journal of Physics A: Mathematical and Theoretical. doi.org/10.1088/1751-8121/abb1e1.