Traffic Adaptive Offset-Based Preemption for Emergency Vehicles

This research analyzed and evaluated a new strategy for preemption of emergency vehicles along a corridor, which is route-based and adaptive to real-time traffic conditions. The method uses dynamic offsets which are adjusted using congestion levels to provide uninterrupted preempted green signal for the emergency vehicle throughout its route. By achieving a higher average emergency vehicle speed, this method promises faster emergency response which results in saving life and property as well as larger emergency service radius for the dispatch stations. The research evaluated the effectiveness of two possible algorithms for offset adjustment using measured vehicle queues. It is showed to reduce the emergency vehicle travel-time by 31 percent when compared to cases without preemption and 13 percent when compared to traditional method of individual-intersection preemption.