Study On The Vehicle Running Characteristics At Urban Intersections

Signalized intersections, as crucial points for uninterrupted and continuum trafficflow transforming into each other, are congested frequently, which leads to the decreaseof vehicles operating efficiency in urban network. As a major component of traffic flowat the intersection, vehicles affect the efficiency at the intersections directly. Thus, tosupply the strategy making of traffic management and traffic control with better theorysupports, and alleviate traffic jam efficiently, analyzing the operating characteristics ofvehicles at the intersections deeply and establishing the exact models are necessary.Operating characteristics of vehicles can be divided into microscopic andmacroscopic ones. The main studies of microscopic characteristics of the vehiclesconsist of the behaviors of lane change, acceleration and deceleration, stop and yield.These behaviors are determined by driving task and the surrounding traffic environment,and different psychology results in different behaviors. Thus, in terms of microscopiccharacteristic, the research in this paper analyzed the surrounding objects influence onthe vehicle, and made deeply analysis and model establishment about the microscopiccharacters come true. Macroscopic characteristics consist of vehicle arrival distribution,propagation delay and traffic efficiency, and so forth, and these characteristics aresignificantly beneficial to traffic control, traffic organization strategies making andeasement of traffic congestion. To deeply analyze the characteristics, in this paper, theyare described qualitatively combined with probabilistic models, traffic flow theory andshock wave models. The models established in this paper are tested with video data.The research in this paper can enrich and develop the traffic flow theory in urbanroad, and supply the making of traffic control strategies and traffic managements withtheory support, which aims to strengthen security and enhance the inefficiency atintersection. There are four major sections in this paper, which shows as following:(1)The situations that the drivers are affected by psychological stimulation atintersections are studied. Through analyzing the conditions which the objects haveinfluence on the drivers’ psychology, and studying when the vehicle are in different states,two kinds of safety distances between two vehicles are proposed with static and movingtraffic flow separately, and the percept-respond process are depicted. Eventually, based on the definition of the scope and intensity of influence on the driver, the general modelwhich describes the affect on drivers at intersections is established.(2) The driving behaviors and decisions are analyzed when the driver is affected bydifferent psychological stimulations. With analyzing the driver’s decision-makingprocesses in kinds of stimulus situations, combining with Bayesian probability theoryand fuzzy clustering theory, a driving behavior decision model is created. To establish arelationship model between psychological pressure and operating characteristics ofvehicles, the driver’s psychological stress model and the perception-respond diagram areused to calculate driver’s psychological pressure under different circumstances. Thisrelationship model is analyzed for its feasibility.(3) Driving behavior model with blocking and friction interfering at intersection isestablished. This section Combines the relationship model between operatingcharacteristics and drivers’ psychological with driving behavior decision model to studythe process of decision-making in the situations of friction and block interferer during thedischarge process, and analyzes the psychological effects on the drivers. To create thedriving behavior models with interfering of blocking and friction interfering, thebehaviors of driver and vehicle are transformed into mathematical abstractions.(4) The macro-operating characteristics involving arrival distribution, delay andpropagation were studied. In terms of macroscopic characteristics, from the flowrelationship between upstream intersection and downstream intersection, analyzing thearrival distribution and vehicles operating characteristics at end of green interval, thearrival distribution model, delay model and driving behavior at the tail of green periodwere established. Combined with probability theory model of mathematical statistics,flow-density-velocity relationship model of traffic flow theory, shock wave models,macroscopic characteristics were described qualitatively, and models established in thissection are tested with video data.Finally, the research progress and the main results of the paper are summarized, andthe main problems existing in the research and the future work are proposed.