Wireless Sensor-Based Traffic Light Control

Real-time traffic light controllers (TLCs) play a major role in optimizing traffic flow. We uses wireless sensor network (WSN) to decrease vehicles´ average trip waiting time (ATWT) on the road. We studied the performance of using one sensor and two sensors and designed corresponding controllers. In the case of one sensor we developed two models; a non-occupancy detection (NOD) and an occupancy detection (OD). NOD detects passing vehicles only whereas, OD detects vehicles that pass the sensor or stop at it. In both methods, we changed the sensor location relative to the traffic light´s location. We then used two sensors to calculate number of vehicles waiting or approaching a traffic light. We tested different distances between these two sensors. Two sensors-based controller outperform the one sensor controller and produced results comparable to the ideal control that knows exact number of waiting vehicles. In analyzing our simulation, we found that the distance between the two sensors does not affect the performance of our design. Hence, placing both the sensors close to each others produce the best performance in terms of quality of the data and reduce energy consumption which leads to extending the life time of the WSN.