Building and Simulation of a Modified Cell Transmission Model for an Urban Expressway

For supporting analyses of traffic evolutions and traffic situation assessment, a Modified Cell Transmission Model (MCTM) for urban expressways is presented. The calibrated Van Aerde single regime model is used to replace the supposed triangle or trapezoid structural fundamental diagram, which makes the MCTM more adapting to describing expressway traffic flow characteristics. For different link connection types on expressways, rectilinear, merging, diverging and weaving transmissions of traffic flow are formulated using the proposed MCTM model. Using the designed experimental expressway section, three scenarios are simulated using CTM, MCTM, and INTEGRATION respectively, including normal traffic simulation without any incident, traffic simulation with accident, and traffic simulation with accident and managements. Results show that MCTM model can directly show the traffic flow condition and evolution process on expressways.