Express Way Traffic Capacity Based On ITS

Characterized as large flux,high speed,safety and comfort,highway developsrapidly and plays more and more important role in road-based transport system,and hasmade great contribution to improving the existing transportation situation and promotingthe development of thenational economy.However,the highway capacity reduction andthe problems resulting from it,such as traffic delay,traffic safety,environment pollution and energyconsuming,have constrained badly the effect of highway transportation.According to relevant study andpractices,thetraffic control and management to freeway is effective way to solving these problems.The traffic control and management system of freeway is a Varying with time,large-scale complexsystem,which includes people,vehicle and road,and the traditional control method and generalmanagement means could notreach the satisfied result.Thus,with the development of ITS,based onintegrated and intelligent notion of traffic control and management,regarding intelligenceengineering(including computer scicnce,artificial intelligence,systemsengineering) as methodology whichsolves large—scale complex problems,this paper studies deep on the highway capacity.The mainresearches can be summed up as following aspects:1.This paper engaged in highway capacity study of basic theory.It carried out the basic theoryresearch from the system in terms of highway capacity,and studied the characteristics of highway trafficflow,then made the traffic volume,speed,density,headway and headway parameters clear such as thedefinition of traffic and that,as well as the relationship between each parameter.On this basis,it studied thehighway capacity theory,defined the concept and classification of capacity,studied calculating models ofthe capacity,and then analyzed the existing problems of currcnt theoretical models.2.This paper studied the traditional collection methods of highway capacity,and the analysis focusedprimarily on the observation apparatus and equipment,data acquisition methods,the processing andanalysis of the observation data,and it mentioned the analysis of the problems in the traditional way ofinformation collection.3.This paper researched on the highway communications,monitoring and control system structure and function,and then it engaged in various types of traffic detectors and the performance of comparativeanalysis and selection.Further morc,it has bcen finished of the design for the highway based oncommunication,monitoring and control system information extraction capacity highway system,thehighway capacity research data sourcc.4.This paper researched on the information of the highway capacity analysis of the actual system.Based on the traffic flow data and the traffic amount data of each toll station detected by the traffic detectorfrom the Highway Monitoring System,we built the traffic assignment model,that's to say determining theactual capacity by the establishment of OD table,traffic generation,traffic distribution,traffic assignment.5.Thc paper studied the information issue system of the highway capacity,and analyzed the design ofthe information issue system and the outfield equipment build and the matters needing attention.6.The paper studied service level of the highway service network,compared the highway service levelgrading standards in the US with that in our country.And according to the high speed highway networkcharacteristic,we established the service level evaluating indicator system for the service level of thehighway network.7.The paper studied decision model of the service level,put forward the concept of the high speedhighway network average practical capacity,and set it as policy-making goal.And the degrees of thepossibility and satisfaction also have been introduced in the research of the service level of the highwaynetwork.Based on the degrees of possibility and satisfaction,a service level decision model for thehighway network has been established,thus the static classification which is based on the highway servicelevel has been changed into the dynamic classification which is based on the degrees of the possibility andsatisfaction.Finally,conclusions of all research efforts in the paper are drawn and further research directions areprospected.