Optimal Sensor Density for Freeway Travel Time Estimation with Multi-Class Traffic Flow

Due to its significance for advanced traffic management systems and traveler information systems, travel time estimation is usually selected as the objective for optimal freeway sensor density. Unlike most existing studies focusing on the homogeneous traffic flow, this paper develops a method with the consideration of multi-class traffic flow. The multi-class LWR model is used to depict the traffic dynamics, particularly the shock waves. Then, the approximate travel time can be obtained with such approach as midpoint method, and the optimal sensor density can thus be derived. With this work, it will be useful to the sensor location problem for multi-class traffic flow in real freeway management systems.