Calculation Of Traffic Capacity Of Bus Priority Road In Mountainous City Model Study

With the continuous increase of the number of motor vehicles,urban road traffic congestion continues to worsen,public transportation priority has become the most direct and effective way to solve the problem of insufficient urban road conditions and unsatisfied traffic demand.Although the priority development of bus has achieved good results,but as one of the important technical standards of urban bus planning,construction and management,the capacity of priority bus lane has not been given corresponding provisions in the existing national norms,so it is necessary to study the capacity of priority bus lane.In mountainous cities,there is no more than motor lane,and the bus priority lane is mostly connected with the road opening directly by the outermost lane.Vehicles entering and leaving the road opening will occupy the bus priority lane,affecting its capacity.More at the same time,the mountain city stop for the bus bay(straight line and bus bay stop hardware isolation bus bay stop),linear stops is less,anchorage set up different forms of traffic capacity is different,the influence of mountain city bus priority road traffic capacity is set up by the bus stop form and road openings,the influence of and influenced by intersection signal and other transportation facilities.It is of great significance to study the main influencing factors of bus priority lane capacity in mountain cities and establish the calculation model for bus route planning,bus priority lane design and operation management in mountain cities.Taking Chongqing,a typical mountainous city,as an example,this paper selects Xuefu Avenue(4km-8km)bus priority lane section for research,and determines the main influencing factors of bus priority lane capacity.On the basis of the existing traffic capacity calculation model,the main influencing factors are considered to construct the traffic capacity calculation model.At the same time,considering the influence of green signal ratio,the intersection capacity optimization model was built.Finally,based on the multiple linear regression model,the capacity calculation model of the whole bus priority lane was built.That is to realize the mastery of the traffic capacity of bus priority road in mountain cities,to provide a theoretical basis for the reasonable arrangement of bus scheduling in mountain cities,and to ensure that bus priority to meet people’s travel needs to the greatest extent.The main research contents of this paper are as follows:(1)Determine the main influencing factors of the traffic capacity of bus priority lanes in mountainous cities.Based on the analysis of road characteristics and vehicle operation characteristics of priority bus routes in mountainous cities,10 factors affecting the capacity of priority bus routes in mountainous cities were selected.By comparing various weighting methods,the analytic hierarchy process is selected to calculate the relative weight of each influencing factor,and the main influencing factors of traffic capacity are determined by the relative weight.The results show that the opening of section,the setting form of stop station,the green signal ratio and so on are the main influencing factors of traffic capacity of bus priority road in mountainous cities.(2)Establish the calculation model of bus priority road sections and intersections in mountainous cities.On the basis of the ideal capacity calculation model of the road section,considering the influence factors such as the opening of the road section and the setting form of the stop,the capacity calculation model of the bus priority road section is established.Based on VISSIM simulation software and traffic survey data,the calculation model of the correction coefficient of the influencing factors of traffic capacity was established by using the idea of occupancy time.The traffic capacity optimization model of intersection is established by modifying the traffic capacity calculation model of bus priority road section with green signal ratio.(3)Build the capacity calculation model of the whole bus priority road in mountainous cities.Consolidate the capacity of the entire bus priority lane.The characteristics of the main factors affecting the capacity of bus priority lanes were analyzed by MATLAB software,and the capacity calculation model of the whole road of bus priority lanes was established based on multiple linear regression model.It has been proved that the regression equation has a guarantee rate of more than 95%.At the same time,the calculation model of the number of overflowing buses in different stops is established.(4)Select Yunan Avenue(8km-Huaxi)bus priority road to conduct a confirmative study.First research section open,stop setting form,green letter than traffic data,such as generation into the calculation model for computing capacity,ideal capacity calculation according to the headway,collecting different sections(ROADID)unit open,relatively smooth,go slow and congested state,GPS data bus for 5 min flow,speed and density.The collected flow,speed and density were fitted.According to the fitting diagram of"flow-density-speed" relation,the maximum traffic volume that could be observed under the saturated flow of the basic section unit for 5min was determined,and it was converted into the hourly flow as the actual traffic capacity of the section.The ideal capacity and calculation results of the model are compared with the maximum traffic volume that can be observed,and the error and error ratio are calculated.The results show that the error ratio is within 6%,reaching the acceptable range.Therefore,the capacity calculation model of priority bus lanes in mountainous cities proposed in this paper can accurately calculate the actual capacity of priority bus lanes in mountainous cities.