An exploratory shockwave approach to estimating queue length using probe trajectories

In this article, the authors present an innovative approach for signalized intersection performance measurement using probe vehicle trajectory data, focusing on queue length estimation. Critical points, defined as the data points representing the changes in vehicle dynamics, are the keystone of the methodology. The author then present a threshold-based critical point extraction algorithm, which has the potential to reduce the communication cost in future real-time probe data collection application. A shockwave-based method using the critical points to detect the signal timing provides the basis for cycle-by-cycle performance measurement. The authors propose a queue length estimation method as a case study for signalized intersections. This approach was tested by simulation and Next Generation Simulation Project data. Results indicate promising outcome of the trajectory-based method.