Study On Green Wave Coordinate Control Of Urban Arterial Traffic

The traffic signals not only can make sure the traffic flow travels throughthe junctions securely and orderly, but also maximize the traffic flow when thesignals parameters are configurated reasonably. A research on the signalsconfiguration of arterial traffic is aim to keep the flow travels through severaljunctions without stop, so that the average delay time and stop times arereduced. However the calculation of green time, phase error and phase orderoptimization are difficult due to the dynamic features of traffic flow and thenonlinear relationship between traffic flow and occupancy. What’s more, thecoupled relationship of junctions’ parameters makes it different for traditionalmethods to maximize the traffic capability of all phases while the green wave isformed in the arterial traffic. This paper focuses on the traffic signals of arterialtraffic, and several modeling and parameters optimization methods arepresented to solve the problems.Firstly, the calculation methods of traffic flow and average speed arepresented based on the three-level road modeling. Then the correlation ratio is rectified in allusion to three-level road and is helpful to the division of greenwave band. The calculation of direct proportionality factor is also presented sothat the traffic flow can be got when the detectors are damaged or the directphase and right phase are overlapped.Secondly, a method to reduce the deviation of phase error is presentedbased on the fuzzy logic, so that the phase error reflects the changes of trafficflow. The green time of direct phase contains two steps: the time to release thetraffic waiting behind the stop line and the time to release to traffic travelling inthe green wave band. The first time is linear to and green time of theupstream junction’s direct phase. The second time is calculated by the2-inputfuzzy controller based on the fuzzy logic.Thirdly, to further improve the performance index of junctions, reduce theaverage delay time and stop times, the paper presents a green wave controlmethod based on the phase order optimization, which details the configurationof green time and when to start the green time phase while the phase orderoptimization is also activated.Finally, the modeling method and the controllers are simulated based onthe software environment of Matlab and VISSM, the results show the efficiencyof designed methods compared to the traditional methods.