| Wide spreading of electric bicycle and rising of bicycle sharing system has contributed to the rediscovery of cycling in Chinese urban commuting.A great many of conventional bicycles,electric bicycles,public bicycles and shared bicycles are running on the urban streets.The bicycle type of new power and new using mode increases the complexity of bicycle flow characteristic bringing about much problems of transport operation and safety.This causes new challenges to transport planning,cycling facility design and traffic management.Faced with the great number of operating and safety problems by the fast cycling development and the pressed requirements from transport planning,cycling facility design and traffic management,supported by National Key Basic Research Program of China(No.51238008)and National Natual Science Foundation of China(No.51408145),the study aimed at exploring the operating mechanism and characteristics of mixes bicycle flow and considered the basic segments of separated bicycle lane and the access zones by bus stop on cycle lane as the main research objects.Based on the field investigation and analysis on the operation characteristics of bicycle flow,cycling simulating model and capacity calculating method were established.After that,according to the features of cycling flow and the problems existing in real riding,a optimization method for cycling facility design and some specific schemes were proposed.The paper obtained the following results and conclusions:(1)Methods Of Data Collecting and Extracting For Bicycle OperatingData collecting and extracting methods were proposed respectively for the basic segments and bus stop access zones of separated bicycle lane.The approaches includes the objectives of investigation,contents and modes of data capturing,field procedures and extracting method of video data.(2)Characteristics of Bicycle Riding and Group RidingSummarizing the previous study results of other scholars and field investigation were used to study the features of bicycle riding and compared the difference between conventional bicycle and electric bicycles on their kinetic properties emphatically.Statistical analysis were carried out on bicycle group size,group density and velocities while related analysis was done on them.The volume threshold that abreast riding happens at and the passing comfort related to riding lateral space were studied using logistic regression,this chapter gained these results:1)bicycle riding properties including physical size and mass,cycling territory and the computing formulas,cycling sight distance,acceleration and deceleration,velocities and turning features;2)bicycle group size,densities,velocities and their relationships;3)the volume threshold for abreast riding is 1075bics/h/m;4)the 85-percentile lateral gaps for comfortable passing are 0.48m(distance from center of the passed cyclist to the nearest curb),1.48m(distance from center to center of the passed cycle and the passing cycle)and 0.56m(distance from center of the passing cyclist to the nearest curb).(3)Clustering and Statistical Modeling of Bicycle Free Flow SpeedThis part firstly identified the significant factors influencing bicycle free flow speed using general linear model and analysis of variance,then sorted these factors by their impacts and merged the levels or groups under each factor,applied K-means to cluster the subclusters generated by combination of the factors.The obtained results and conclusions are as following:1)gender and age of cyclists,bicycle type,lane width and lateral position influence bicycle free flow speed significantly;2)the impacting order of the factors above are bicycle type,lateral position,gender,age and lane width;3)three clusters are obtained and their distribution are N(4.17,0.90).N(5.60,0.87).N(6.62,1.53).(4)Bicycle Simulation Model based on Velocity Obstacle AlgorithmThe chapter established a new bicycle simulation model based on velocity obstacle algorithm and according to three riding conditions.The detailed process of linear constraints proposing for the model and a speedy solution to the model were described.Then the validation of the model were proved qualitatively and quantitatively.In the end the difference of the new model from the previous models were discussed.(5)Analysis of influent factors and Estimation of Bicycle Lane Saturated Flow VolumeThe chapter studied the significant factors of bicycle lane saturated flow volume,computed the bicycle equivalent unit(BEU)of passing cyclists and electric cycle using designed simulations.Through comparing BEUs of two types of cyclists,the affecting levels of significant factors of bicycle lane saturated flow volume were determined.At last,the equations for the saturated volumes of general bicycle flow and typical bicycle flow were proposed by regression analysis.The following results and conclusions were obtained:1)the significant factors of bicycle lane saturated flow volume were ratios of cyclists applying cycling strategies and the proportions of bicycles of different types.2)the BEUs for passing cyclists and electric bicycle were 0.918 and 0.641 respectively.3)In contrast to cycling strategies,bicycle type was more influential.10%rise of electric bicycles and passing cyclists in bicycle flow will increase 99bics/h/m and 21 bics/h/m in saturated volume.(6)Operation Study of the Bus Stop Access Area on Bicycle LaneBicycle flow,bus passengers and the conflicts between the two were analyzed using statistical analysis.Then a comparison was conducted to find the influence of facility parameters of bus stops on bicycle flow capacity.After that,accidence estimation analysis was to identify the key factors impacting bicycle-passengers conflicts.The main conclusions of this part are:1)linear bus stop imposes more influence on bicycle lane capacity than bus bay stop;2)bus stops with fewer exits and exits set near the end impact lane capacity less.3)the lower ratio that the overall exit width covers a stop length contributes a less reduction to lane capacity;4)bicycle-passenger conflicts are positively related with passenger volume,bicycle arrival volume,lane width,crossing time of passengers,exit density and setting a linear bus stop and negatively with the ratio that the overall exit width covers a stop length,setting bus bay stop,bicycle flow speed and platform length.(7)Optimization Methods and Design for Separated Bicycle LaneThree operating conditions of separated bicycle lanes installed on midblock were divided.Then a generalized optimization method,related data collection and procedure were proposed.Using the method,optimization designs on basic segments,bus stop access zone,and access and egress segments were conducted.Bicycle lane capacity distribution were obtained by fitting the data generated by the simulation model based velocity obstacle algorithm.On basis of that,a lane width calculating formula considering bicycle service volume and the ratio of bicycle type was proposed.According to the conclusions in bicycle abreast riding and passing phenomena study,the improved width for bicycle lane were put forward.Based on the conclusions of bus stop influence study,the design principles and parameter optimizing schemes were proposed.To solve the riding and safety problems at the access and egress area of bicycle lanes,widening and bend-out were used. |
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