Workload Estimation Algorithm in Parallel Traffic Simulation

Parallel traffic simulation is a critical component in large-scale traffic simulations and real-time traffic simulations. Dividing workloads evenly to multi-cores and multi-machines is a challenge in parallel traffic simulations. Current researches focus on map decomposition algorithms. However, without effective workload estimation algorithms, map decomposition algorithms tend to output imbalanced partitions. This paper proposes an elliptical-shaped workload estimation algorithm. The main idea of the algorithm is to assign the computational cost of a vehicle to links in an ellipse, whose centers (or foci points) are the vehicle's origin node and the destination node. The algorithm is evaluated on a test-bed using a mesoscopic traffic simulator on the Lower Westchester County network. Case studies show that the new algorithm reduces 36% of the estimation errors in current length of links based workload estimation algorithms.