Research On Traffic Demand Forecast Method During Winter In Cold City

The scientificity of modern city road traffic system planning and constructiondepends on technical achievement in road traffic demand forecasting research.Therefore, in order to improve the rationality and scientificity of road traffic demandprediction, domestic and overseas cities have spent lots of manpower and materialresources conducting traffic investigation, which is used to develop the traffic demandforecasting models. These models are employed to analyze the current and future trafficoperation situation in cities, this provides data supports for city road traffic systemplanning and construction decision making. However, because of traffic survey costinga lot, most cities conduct the traffic investigation every decade, or even decades.Moreover, almost all traffic surveys are carried out in summer, the collected data is onlyutilized to predict the traffic condition during summer season.In Northern China, the features of cold climate in large cities determine that thetraffic has different characteristics in winter and summer. Winter road traffic systemperformance affected by various influence, like traffic supply and demand, the coldweather, snow and so on, is very diffident from that in summer. Therefore, in order topredict the future traffic conditions of cold climate city with the traffic model, it needsto create a different model of traffic demand forecasting for winter and summer, andcollect traffic survey data in different periods. Due to the impact of climatic conditions,carrying out a large-scale survey of traffic in cold climate city is very difficult. So it isnecessary to study the traffic laws governing the operation of the traffic in summer andwinter, and the impact of climate on human traffic models, vehicles, roads and othertransportation elements, to analyze these factors used for winter traffic demand forecast,and to deduce winter traffic demand according to the survey data collected in summer.Hence, one of the objectives of this study is proposed an approach to predict winter roadtraffic condition based on summer traffic relevant data.Winter road traffic demand forecasting model has broad application space, whichnot only can simulate driving conditions of all kinds of motor vehicles in winter androad traffic conditions of vision year, but also help to sort recent transportationconstruction projects scientifically. The relationship of static parking demand anddynamic demand is investigated using the road traffic demand forecasts in winter. Inthis way, the road traffic demand and central district parking demand prediction can beobtained using the data collected in summer, even if traffic survey cannot be conductedin winter. The proposed model is used to analyze road traffic operation situation.Therefore, without such a large-scale survey of the winter traffic, we can build a winterroad travel demand forecasting model to simulate the actual traffic situation analysis ofthe winter, which can save a lot of traffic investigation costs and improve the accuracy of traffic demand forecasting to ensure the project can operate smoothly.This paper relays on Natural Science Foundation of Heilongjiang Province andHarbin City Comprehensive Transportation Planning project. Based on the summary ofrelevant research results at home and abroad and using the data related to Harbin andDaqing, it discussed deeply about the method for establishing the travel demandforecasting model of cold climate city and parking demand model for urban centers inwinter.In this paper, the prediction method of urban road traffic demand has beenelaborated. Traffic generation forecast method mainly includes growth rate method,original unit method and function method. Traffic mode prediction has two divisionmethods: divided by multilayer or monolayer and according to the service providers.The latter’ prediction methods mainly consist of sharing rate curve method and modelmethod. Traffic distribution forecast mainly contains growth rate method, gravity modelapproach and opportunity model approach. Traffic assignment model mainly includesfixed demand distribution, elastic demand forecasting and portfolio allocation. Atheoretical foundation for the application of the text is listed. This paper established aprediction indicator system according to the factors of road traffic demand forecastingmodel, created an index system of road traffic demand forecasting model based on thecharacteristics and the principle method of selecting indexes, and come up with the41specific indicators term of urban road traffic demand forecasting model. Usecomprehensive evaluation and sensitivity theory to analyze the sensitive degree of thewinter cold, snow to the model and further screened18specific indicators which have agreater impact on building the model.The characteristics of residents’ trip under different temperature conditions is beinvestigated and analyzed to ensure the indicators of resident trip characteristicsconstitute according to the methodological principles of picking index. Then makesurvey of residents’trip during spring and summer alternate, winter and spring alternate,particularly cold period, and analyze the difference of residents’ trip between thedifferent temperature conditions.According to the different winter city survey, this paper got the pavement conditiongrading of five road grades under five friction coefficient conditions, and the mainimpact of the low temperature to the vehicle through the survey of vehicles speed underlow normal road conditions. Through the existing road capacity calculation methods,correct and obtain the calculation method of road sections lane capacity in winter.Finally, according to the influence of low normal road to starting lost time ofintersection and average time interval of vehicle passing the stop line, establish acalculation method of typical intersection capacity under low normal road condition.Through the analysis of impact of factors such as low temperature, snow and etc.on elements and parameters of building trip generation model, split model, traffic distribution model and traffic assignment model, the paper revised the original functionmodel. Then it set up the function model of residents-travel effect in cold city. And itput forward to the way of building the model of means of transportation in winter by themethod of preliminary classification of non-flexible means. The linear regression modelof preliminary classification of non-flexible means with factors of land-mixed degreeand bus accessibility was established; And the applicable model of road impedancefunction among traffic distribution model in cold city was proposed; The entropydistribution model based on the Eigen vector of five order origin moment wasestablished as well. Meanwhile, it gave the calculation method of delay function on thewinter road in traffic assignment model and proposed the method of traffic demandforecasting model on the road of cold city. Finally, the paper took Harbin for exampleand established the traffic demand forecasting model on winter road. Furthermore, theproposed model was utilized to analyze the effects on periphery traffic operation ofNorth loop overhead road in Harbin.According to the travel demand forecasting model of cold climate city in winter,the winter road travel demand forecasting model was established, in Harbin, forexample. The regional traffic impact of North Ring Road elevated program in Harbinwas evaluated using the winter road travel demand forecasting model, and therelationship of static parking demand and dynamic demand was established. Using thedata of Daoli central area in Harbin made a validation of analytical which got a goodeffect.