An Optimized Method for Reducing Traffic Emissions in Arterial Road Using Coordinated Signal Control

To reduce traffic emissions in an arterial road system, an improved calibration method on the basis of specific power of vehicle is proposed to compute the emission factors during the period of traffic light.An optimization model for allocation of spatial-temporal resources is developed for one arterial intersection group.The decision variable is the effective green time in each phase, and the objective function is to minimize the total emissions for all intersections.By analyzing the relationship between the delay for one platoon and the phase difference between adjacent intersections, this optimized model aiming at minimizing the delay for one platoon, is amended.A case study is carried out to verify this model.A control scheme for traffic signals is firstly obtained as a reference by using traditional methods.The emission factors during the period of traffic light are calibrated by Vissim software.A control scheme for traffic signals is optimized by this proposed method.The results indicate that the emission factors of each pollutant during a green phase are explicitly greater than which during a red phase.Compared with referenced control schemes for traffic signals, both delay of vehicles and traffic emissions decrease by 8-11% at each intersection when the optimized control scheme is adopted.It shows that this proposed model can be applied to decrease both the delay of vehicles and traffic emissions in an arterial road system.Thus, it can generate a coordinated control scheme for traffic signals, and relieve traffic jam.