A survey of vehicular communications for traffic signal optimization

Traffic congestion is an ever increasing problem on our roadways and city streets. The main contribution of this survey is a taxonomy of adaptive traffic signal control strategies achieved through various levels of vehicular communications.Strategies to optimize traffic signals fall into three categories based on the level of vehicle involvement. The first category involves those strategies that utilize legacy devices with no vehicular involvement. The second category comprises those strategies that utilize vehicles on the road to wirelessly transmit data about themselves (e.g. location, velocity). The third category involves strategies that utilize the vehicles' on-board computation power to help optimize traffic signals. The bulk of this survey deals with the second category as it appears to be the most prevalent in the research literature. We are however, quick to point out that the third category seems to be gaining momentum, as the prevalence of smartphones has suggested supplementing legacy traffic monitoring with traffic-related reports submitted by the driving public.