Traffic signal coordination and queue management in oversaturated intersection.

PDFTech ReportNEXTRANS Project No. 047IY02Traffic signal control systemsOversaturation (Traffic flow)North Central StatesPurdue UniversityNEXTRANS Center (U.S.)Hajbabaie, AliMedina, Juan C.Benekohal, Rahim F.Purdue UniversityNEXTRANS Center (U.S.)US Transportation CollectionTraffic signal timing optimization when done properly, could significantly improve networkperformance by reducing delay, increasing network throughput, reducing number of stops, orincreasing average speed in the network. The optimization can become complex due to largesolution space caused by many combinations of different parameters that affect trafficoperation. In this study three different methods are used to find near-optimal signal timingparameters in transportation networks. The methods are: Genetic Algorithms (GA), EvolutionStrategies (ES), and Approximate Dynamic Programming (ADP). Each method is introduced, thesignal timings associated with them are explained and some important measures ofperformance of the networks are determined and compared. One small network with 9intersections and one medium network with 20 intersections were used for evaluating theoptimizations methods. Three general cases (Cases 1, 2, 3) are discussed in this report. For thesmall symmetric network, three levels of traffic loading are used (no overload, 10% overloadand 20% overload). For the medium network (modified Springfield IL downtown network), twolevels of entry volumes are used (750 and 1000 vehicle per hour per lane)