Measuring Real-Time Road Traffic Queue Length: A Reliable Approach Using Ultrasonic Sensor

Traffic congestion not only lengthens the travel time of a commuter but also increases the fuel consumption as well as air pollution. Thus, traffic congestion management has drawn significant research interest over the past few years. On the other hand, a reliable estimation of the congestion density via traffic queue length measurement at any segment of the road in real time is highly desirable to control the traffic congestion in the urban areas. Thus in this paper, we focus on how to estimate the congestion density in a reliable way and propose a real-time traffic queue length measuring approach for the signalized intersections using ultrasonic sensor node (USN). The experimental results demonstrate that our proposed approach achieves almost 100% success in vehicle detection if the vehicle queue is formed within a distance of 2.5 m from the position of USN. Moreover, our proposed approach also attains high success rate in the detection of vehicle queue even when USN is placed 2 m away from the vehicle queue and it lies in between two vehicles by having the intervehicle distance falls within the range of 30-80 cm.