An Improved Cell Transmission model for Simulation of Traffic Flows of Ring Roads

Traffic flow modeling has always been a foundational component of transportation studies.Traffic flow models can be used for forecasting traffic flows and then providing a basis for signal control.In this study,an improved cell transmission model(MCTM) is developed for the ring roads in Beijing.The MCTM removes the restriction of the original CTM that requires equally partitioning space to develop cells,but it takes density as its state variable,instead of the number of vehicles in the cell.Traffic flow transmission rules between cells are defined for different connection mechanisms between cells,including simple connection,merging and diverging.A comparison is made between the simulated results of the MCTM and those from the microscopic traffic simulation model Paramics.The results show that,although it is less complex than CTM in computation,the MCTM still can describe the dynamic characteristics of traffic flow on the ring road accurately and effectively,and can be used in the future for traffic flow forecasting and ramp metering.