Safety-oriented Speed Guidance of Urban Expressway under Model Predictive Control

In order to improve the efficiency and safety level of urban expressway, speed guidance control was utilized to optimize the traffic flow. Inner ring expressway of Shanghai 5 km long was modelled in VISSIM and conflict statistical analysis was carried out in SSAM based on the data of vehicles trajectory. The collaborative optimization method to intervene the crash risk using speed guidance control was given. Log-linear model was established according to the speed-related variables and the model was adopted as the objective function of quantify traffic safety. Then simulation was carried out integrating MATLAB, VISSIM and VB.NET under extended macroscopic dynamic traffic flow model. Speed guidance control system oriented quantified traffic safety for urban expressway using model predictive control was established. Then numerical simulation was launched, the results show that total traffic conflicts decrease 29.1 %, travel time of monitoring link reduces 45.3 %, and variance of travel time reduces 47.8 %. Under the speed guidance control, safety and efficiency of expressway both have been improved, which has important reference for delicacy traffic control and management. (Received, processed and accepted by the Chinese Representative Office.)