Study On Signal Coordination Control Of Irregular Artery

In the city of road network, the irregular traffic arteries exist inevitable, which are causedby the deformity intersection, bottleneck section, cultural relics and early unreasonableplanning and so on. The irregular arteries are common in the mountainous city road networkand have obvious traffic characteristics, which have obvious influence on road capacity andlevel of service. Signal coordination control has significantly effect on improving arterialcapacity, so it is necessary to study on signal coordination control of irregular arteries.The traffic characteristics and their influence on road capacity of irregular traffic arteriesare studied. We mainly analyze the traffic characteristics of traffic arteries which containdeformity intersection. The analysis results show that the crowed phenomenon is occurredeasily and its road capacity is decreased obviously.On the bases above, the main intersection signal timing parameters are calculated. Atpeak times，intersections appear over-saturated phenomenon (sum of maximum saturated flowrate of each signal phase is more than0.9,namely Y>0.9). We introduce relative concept ofsum of maximum saturated flow rateY’and relative concept of cycle time C’ as the middlevariable to calculate related signal cycle, green time and split parameters by using Webstermethod. In addition, the calculated cycle is decided the signal system cycle by comparing thecommon recommended cycle120s with calculated cycle.On the bases of calculated signal cycle time, phase sequence and phase designing, thepaper calculate bandwidth, band speed and offset of green wave band. In this paper,considering the traffic volume is large and the traffic flow is steady flow, the actual speed isused during calculating relative parameters to ensure the offset is calculated reasonably.At last, the paper adopts simulation method to evaluate the control project by usingVissim software. Through analyzing the evaluation result, the level of service of intersectionis improved from grade E, F and F to D, E and F. Average delay of every vehicle is reducedfrom89.6s to73.8s. In addition, according to the simulation directly demonstrates, we canconclude that the phenomenon of the traffic overflow to the upper intersection is disappeared.So the effect of signal coordination control of irregular artery is obvious.