Recursive estimation of time-varying origin-destination flows from traffic counts in freeway corridors

This research presents a dynamic system model and its on-line estimation algorithm for time-varying freeway origin-destination (O-D) matrices. The proposed model employs information from mainline traffic counts, ramp flow measurements, and macroscopic traffic characteristics to construct a set of dynamic equations, which realistically consider the interrelations between O-D distributions and observed flows under congested conditions. To improve the operational efficiency necessary for real-time applications, a revised model with some approximation have also been developed. Due to the difficulty in acquiring the real-world data, the proposed model was evaluated with simulation experiments. The results of laboratory evaluation indicate that the proposed method offers a promising direction for tackling this complex issue.