A distributed virtual traffic light algorithm exploiting short range V2V communications

The correct and prompt definition of priorities at intersections is one of the key issues for vehicular safety and efficient traffic management. Traffic lights currently control only a limited number of intersections and increasing their number is clearly infeasible due to the high costs of deployment and maintenance. A new solution will be possible in a near future, when vehicles will be equipped with wireless technologies. Their capability of communicating and coordinating to each other will create the conditions for the implementation of a virtual traffic light (VTL) architecture, where priorities are autonomously defined by the involved vehicles. With this scenario in mind, we describe a novel VTL algorithm aiming at defining the priorities of the intersections in a distributed and controlled way. Besides the algorithm description, the main related issues are thoroughly discussed. In addition, a real implementation is detailed and the validation of the algorithm is provided. The testbed, based on the IEEE 802.11p short range wireless technology, has been reproduced in a controlled laboratory environment and in a field trial with equipped vehicles.