Research On Travel Time Reliability Measurement Methods In The Highways

In recent years, with the accelerating of urbanization process, economy also hasobtained large development, people propose a higher requirement about their travelingquality. And the concept of western satellite city is introduced, city groups begin toemerge. Sections of big cities are moved to the suburb gradually, the importance ofhighway in traffic is increasing apparently. However, the growth speed of the highwaycan not catch up with the growth speed of the vehicles. Due to the randomness of thetraffic system is strong, all kinds of random events occur at any time, which leads to theefficiency travelers traveling is lower in the highways, and the time of people’s travelingrises. Travel time gradually go into people’s horizons, and the travel time reliabilityaffects the travel time estimation, which influences people’s travel. How to improve theconvenience of travel, and improve the travel time reliability are research focus of thehighways.Travel time reliability belongs to a classification of probabilistic evaluation index,which combines with traditional evaluation index (average travel time in road network,average speed in road network, etc.). It can evaluate traffic condition in road networkmore accurate and comprehensive, which provides decision basis for highwayconstruction sectors, traffic administration, highway management. Travel time reliabilitymeasurement methods in the highways are as the main research direction in this paper,first highway travel time reliability measurement methods are established, then two typesreliability model of highway travel time, of which are highways basic sections travel timereliability model and highway route travel time reliability model.Highway travel time reliability model. Firstly, this paper describes the definition ofhighway section, and calculates the section travel time of floating cars in the case ofadequate samples size and inadequate samples, then highway travel time probabilitydistribution curve of floating cars is fitted. Highway section travel time of fixed coil iscalculated using the relationship between travel time and flow. Finally, the section traveltime estimation model and the method of calculating travel time reliability are described. Highway route travel time reliability model. This paper proposes a method ofdefining highway route. Thereby highway travel time reliability of basic route isestablished. When vehicle is traveling a whole path, TRTI model is used to calculate pathroute travel time reliability, and IRTI model is improved. When vehicle is traveling aunwhole path, analytical method is used to f calculate path route travel time reliability.Finally, the model in this paper is used to evaluate the route travel time reliability, andlognormal distribution is used during the evaluation the route travel time reliability.