Emergency Vehicle Signal Pre-emption System for Heterogeneous Traffic Condition : A Case Study in Trivandrum City

Emergency vehicles play a critical role in effective delivery of emergency services. Traffic congestion and delay at intersection are the major reasons that increase the response time of emergency vehicles. This study focusses on the need for emergency vehicle signal pre-emption of major intersections for Indian environment, with the limelight on Trivandrum city as the study area. The data comprising of traffic volume, spot speed, existing signal timings and geometric variables were collected for three signalized intersections. The proposed method considers the three approaching scenarios, so that traffic queues at the intersections on a given emergency route can be cleared in advance for an emergency vehicle, while minimizing delay because of unnecessary pre-emption. Emergency vehicle signal pre-emption system design was done which includes the determination of EV detection distance. The proposed design was simulated in a traffic network using a microscopic simulation model using VISSIM Software, which was calibrated with the traffic data collected from the network. The performance of the proposed pre-emption was compared with existing system. The findings show that the proposed method can reduce up to 25 - 30% of emergency vehicle delay at signalised intersection.