Stress Test of Roadway Network Capacity

This paper studies roadway network capacity by applying a stress test method to estimate the ultimate limitation of the roadway network to accommodate the travel demand. The method considers the factors affecting capacity of roadway network and defines the evaluation index of roadway operation quality--the average degree of saturation of traffic flow and the average speed. By using macro traffic simulation and planning software, the average degree of saturation and the average speed are calculated and compared in the computer. If the results are smaller than predefined evaluation index, additional traffic load (pressure) would be released onto the network using a regression based approach or dichotomy analysis. The process continues until the evaluation index is satisfied when the roadway network reached its capacity. This paper establishes the stress test criteria and applies the method to the Huairou District of Beijing to get its roadway network capacity, 104923pcu/h.