Traffic Demand Estimation Method Of Road Section In Congested Situation

Traffic demand on road section is the basis data of taffic management and control.The accuracy of data determines the effective of traffic control measures.The current traffic demand data comes from the traffic volume,but they are not entirely equivalent.When the road section is unsaturated the traffic volume is the traffic demand,the arriving vehicles could completely pass through the intersection.On the other side,when the road under congestion the traffic demand including traffic volume and stranded queuing vehicles.So the traffic demand cannot be repalaced by the traffic volume under congestion.Based on the available literature,this paper summarized the present researches on traffic demand related parameters research,travel time estimation methods and traffic demand estimation methods.And then this paper presented a new traffic demand method under congestion based on the actual traffic demand caharacteristics and influencing factors.Firstly,this paper points out the shortages of traffic demand research.And determined the relationship between traffic demand,traffic parameters and road factors by simulation analysis method and correlation analysis method.And the number of lanes has a great influence on the capacity of road sections.Traffic demand was realted to the number of lanes and length of section.Secondly,travel time is the key parameter of traffic demand.By analyzing the travel time of road section,this paper put forward a travel time estimate method based on the single ALPR device.By analyzing the movement track of vehicels established intersection delay models in different traffic situations.The travel time estimation method combined with related parameters,such as dealy,speed,link length,signal.It is verified the accuracy and reliability of method through the case study on travel time estimation under different saturation levels.Finally,this paper based on flow,travel time and other road factors established a traffic demand estimation model that combined with the traffic demand of each steering,a model for estimating the total traffic demand of different road sections.Taking Jingshi road in Jinan as the case study,this paper proved the reliability of the model by using traffic simulation software and methods.Calculate traffic demand and real traffic flow into the simulation system,then analyzed and compared the simulation results with the actual road network data,such as travel time and traffic volume.And the accuracy of the traffic demand estimation method was verified.