Research On Optimal Design Method Of Rapid Bus Service Network Based On TOD Concept

Bus rapid transit is an important mode of transportation to supplement urban public transport capacity,improve travel efficiency and solve urban congestion.It can efficiently connect the main passenger flow distribution points,and play an important role in urban traffic at home and abroad by providing rapid,large and medium volume,and high-quality services.Bus rapid transit mainly serves the urban passenger flow corridor,as well as the areas where the population and function are gathering.As a transportation mode of large and medium volume,bus rapid transit can enhance the aggregation effect of passenger flow along the route and guide the development of urban spatial structure.However,the network design problem of bus rapid transit mainly focuses on the network structure level,and lacks the research on service characteristics such as service frequency and service mode.The service zone identification always bases on the population or the traffic demand,but ignores the influence of urban structure and the social economy factors.The interaction between service network and bus corridor planning also needs more scientific research.In order to improve the service quality of bus rapid transit,accurately identify service areas and passenger flow corridors,realize the linkage between bus rapid transit service areas,and enhance the attraction of bus rapid transit to passenger flow along the route.The theory and method of spatial distribution identification of TOD blocks,the method of bus corridor situation identification and the design model of bus rapid transit service network are proposed in this paper based on three levels of points,lines and networks,respectively.The main contents of this paper include the following aspects:(1)The TOD concept in bus rapid transit service network design mechanism is analyzed.The relationship between TOD concept and bus rapid transit service network design is analyzed from three levels: city layer,corridor layer and block layer.The characteristics of TOD block and urban bus corridor under TOD concept is analyzed.The stage and function of identification of TOD block and urban bus corridor in the design of bus rapid transit service network is expounded.(2)TOD block spatial layout identification method is studied.The traffic network-activity guidance-group behavior model is constructed based on the spatial multi-criteria decision analysis method.The TOD index is defined to evaluate the TOD potential of urban blocks.On this basis,the traffic network index,activity guidance index and group behavior index are clustered based on spectral clustering algorithm to identify areas where urban traffic supply do not meet residents' travel demand and activity demand,and further to determine the service area for bus rapid transit.(3)A two-stage identification method for urban public transport corridors under TOD concept is studied.The first stage,the K shortest search algorithm is used to generate the alternative set of bus corridor.The block gravity index and the along-line gravity index are constructed to quantify the attraction along the bus corridor,through the influencing factors of bus corridor.On this basis,the optimal model of bus corridor situation identification is constructed with the constraints of time,arc capacity,volume ratio,corridor development and block node development.In the second stage,the principles and methods of bus corridor adjustment are given according to the model calculation results,combined with the characteristics of the bus corridor.(4)An optimization model of bus rapid transit service network design under TOD concept is studied.Firstly,three kinds of bus rapid transit service modes are studied and put forward according to the service characteristics,including large-station fast line,direct fast line and cross-station fast line.On this basis,an alternative set generation method is proposed in this paper,generalized cost minimum,TOD utility maximum and corridor line utilization efficiency are considered as objective function.The mathematical optimization model of bus rapid service network design based on TOD concept is constructed,with the constraints of traffic conservation,maximum tolerance time,line service capacity,transfer times,service frequency and so on.An example is designed to verify the effectiveness of the model and method.It can be concluded that the bus rapid transit service network is helpful to enhance the interaction between urban TOD blocks,and close the coupling relationship between areas along the route.(5)A case study based on the main area of Beijing is analyzed.Firstly,the urban block area is identified,and the service area of bus rapid transit is identified with the TOD potential and uneven characteristics of the block area.Secondly,the layout plan of urban public transport corridor and the development plan of corridor interior are given.Finally,the design scheme of bus rapid transit service network based on TOD concept is obtained,with the geographical distribution of the TOD blocks and the layout scheme of the urban bus corridor considered.