Research On The Arterial Signal Control Method Based On Traffic Composition

A significant feature of urban traffic lies in a complex traffic composition inChina mainland. In foreign countries, advanced urban traffic signal control systemsare generally constructed on a relative traffic composition and they reaches moreremarkable improvement than general single point based on control method, but stillacclimatized. Actually, this should be contributed to many different factors and thatcomplexity of traffic composition is not taken into account grasps the main hand. Inview of the traffic composition complexity, domestic scholars have made greatefforts to enhance the signal control performance. However, more insights wereemphasized on single intersection. By far, fewer achievements have been reportedabout optimal theory and methods in arterial traffic signal control.This research paper is supported partially by Major State Basic ResearchDevelopment Program and National Key Technology R&D Program. It focuses onarterial traffic control under different traffic compositions, strengthening the signalcontrol system contingency, according to road traffic flow changes, so as to reducedelays, improve usage efficiency of road resources and ease urban traffic congestion.The research process combines traffic survey, data analysis, theoreticalmodeling, comprehensive evaluation and traffic simulation. Urban arterials areclassified according to traffic component characteristics induced by data mining.Then, corresponding signal control methods are proposed for each category. In thefollowing content, such indicates as delay and environment indexes, et al, are chosento establish the index system and evaluation model and the proposed control methodsare verified using VISSIM simulation tools.Existing problems are analyzed about typical artertial traffic signal controlsystem and regional types application and general structure of arterial signal controlsystem based on traffic composition. Existing traffic flow detection technologies arealso discussed and video detection method is chosen for arterial signal traffic whichadapts control strategy according to upper intersection detection result. Urbanarterials are divided into three categories by the difference of traffic operationaffected by traffic composition, namely passenger transport arterial, freight transportarterial and mixed transport arterial.In the analysis of the passenger traffic flow characteristics of operation, novel signal control method is constructed by signal phase ahead of time and extendedgreen light time for bus priority through upper intersection detection for more trucksfreight arterial. To passenger transport arterial with less than10percent trucksamong all automobiles, phase model is constructed as the signal control tool,considering the automobile velocity difference in different directions. This propsedmodel is verified by VISSIM simulation, taking Beixin str., Harbin, as the passengertransport arterial.Impact induced by large cargo truck on traffic delays is modeled. Thus thecorresponding yellow light time is put forward for signal control system of freighttransport arterial and the optimized signal cycle model is deduced. This propsedmodel is verified by VISSIM simulation, taking West Liaohe Rd., Dalian DevelopedZone, as the cargo transport arterial.Traffic detection method is presented for signal control system of mixedtransport arterial and fuzzy control model is established according to the trafficoperation characteristics on mixed transport arterial. Extended green time iscalculated by fuzzy control algorithm and a fuzzy controller is designed on the basisof the leading vehicle type, fleet composition, traffic characteristics of primary andsecondary directions and the queuing length in each phase. Phase is adjusted inaccordance with traffic composition and type of leading vehicle. This model isverified via VISSIM, with Xuefu Rd., Harbin, as the Mixed transport arterial.Vehicle delay, stopping times, queuing length and API are selected as theevaluation vector and a comprehensive AHP evaluation model is proposed to assessthe constructed signal control method. Typical arterials are chosen to make thesimulation test by VISSUM as Beixin Str. for passenger transport arterial, WestLiaohe Rd. for freight transport arterial and Xuefu Rd. for mixed transport arterial.Comparison is realized between normal signal control method and this proposed one.The simulation result shows that the proposed signal method can decrease the vehicledelay and improve the average velocity significantly and effectively.