Headway For Motor-vehicle Analysis Of Urban Roads In Cold Areas

Affected by severe weather conditions such as snowfall visibility during the ice and snow period.There are serious hidden dangers in road traffic safety in cold areas.It is necessary to analyze the traffic flow parameters in snow and ice weather.Among them,the headway is the microscopic traffic flow parameter that describes the arrival law and the release law.It is characterized by the time difference between two adjacent motor vehicles passing through the same section in the same lane,Weather conditions affect its value size and distribution.Too much headway,Reduce the road capacity,the headway is too small,there is a risk of adjacent vehicles collision.This paper investigates the time headway of motor vehicles,To explore the change mechanism of time headway under the weather conditions of ice and snow period in cold region,Establish a more realistic distribution model,Therefore,it is necessary to study its variation and application.The main research content is as follows:1.Under the weather conditions of non-ice and snow period and ice and snow period respectively,The time headway of motor vehicles on the road section was investigated by video recording.Parameters are introduced on the basis of weibull model,A weibull modified model was established to characterize the time headway in the ice and snow period in the cold region,Describe the law of time headway variation.The model was calculated and analyzed with the help of 1st Opt software package,The webull model frequency and the webull modified model frequency are obtained.2.The least square method is used to analyze the weibull model and the weibullmodified model,The results show that the fitting effect of the weibull model is better than that of the weibull model in the ice and snow period,The difference value of the results of the two least squares method reached 4.795E-03,It shows that the modified model is closer to the actual observed data and has better accuracy.3.Based on the time headway,according to the survey data of non-ice and snow period,The kinematics model of starting wave is applied,The calculated wave velocities under the two weather conditions are calculated respectively,The values are 18.01 16.17 respectively,The wave velocity is smaller during the ice and snow period,It shows that the model is consistent with the actual trend.4.The relative errors of calculated and observed wave velocities are compared,The variation law of the longest queue length and dissipation time under two kinds of weather conditions was analyzed.Same volume of traffic,The stopping wave velocity during the ice and snow period is 0.80 sm /.Dissipation time is 46 s,10smore than in the non-ice and snow period.Meanwhile,dissipation time are analyzed to provide a basis for traffic management and control.