Study on Valuation of Signal Control Parameters of Urban Road in Cold Region

surface.Saturation flow decreases by 16%, speed and acceleration decreases by 30%, and start-up lost time increases by 27% .Based on the signal control theory of HCM and Webster and the character values of traffic flow under different road environment, the reasonable valuation of cycle length, green ratio, offset, yellow time and red time were analysed, the impact factors and the changes in scope of signal control parameters tmder icy road environment were accessed. Simulation results show that the normal signal control plan can increase delay, queue length and traffic congestion under icy road environment. Therefore, the traffic signal control system should address the suitable signal control plan based on different mad environments.