Research On Optimization Method Of Public Transport Service Network Based On Activity-demand Analysis

Problems such as urban space shortage,traffic congestion,and environmental pollution are becoming increasingly prominent.As an intensive,efficient,green and low-carbon motorized transportation mode,public transport has been paid more and more attention.Developing urban public transport has become the key to optimizing land use patterns,alleviating traffic congestion,and realizing sustainable urban transportation development.However,due to the impact of private motorized travel,as well as the low service level and lack of competitiveness of public transport itself,the development of public transport has encountered serious bottlenecks.Faced with the increasingly diversified travel demand and the continuous transformation of public transport travel from “route-level” to “network-level”,the traditional optimization idea of public transport network based on passive response to travel demand is powerless.Due to its insufficient consideration of the relationship between daily activities and travel demand,the improvement of public transport efficiency is limited.Therefore,the concept of bus route optimization needs to be realized from “passive adaptation” to“active guidance”.This paper aims to explore a new public transport network optimization idea.From the perspective of travelers’ daily activities and public transport demand characteristics analysis,this paper explores the passenger flow agglomeration mechanism and grading characteristics of public transport stations,analyzes the topology structure of public transport network and carries out network reconstruction and optimization,so as to avoid the limitation of traditional bus route optimization based on route demand,and provide theoretical support for public transport network optimization and service model innovation from the perspective of passenger demand agglomeration guidance.In view of the anchoring effect of rail transit on the public transport network and the flexibility of conventional bus route adjustment,this study mainly considers the public transport network optimization from the conventional bus level.This study firstly analyzes the distribution characteristics and its generation mechanism of residents’ activities,and the characteristics of bus passenger flow at the bus station level from two dimensions of time and space.First,this study uses the residents’ travel survey data to analyze the travel characteristics;then comprehensively use the mobile phone signaling data and the residents’ travel activity survey data to explore the spatial-temporal distribution characteristics of residents’ daily activities;and use activity origin-destination(OD)as the breakthrough point to analyze the characteristic changes of activity flow;combined with points of interest(POI)data,this paper analyzes the generation mechanism of activity spatial distribution characteristics from the perspective of land use.And the bus IC card data and route station geographic information data are used to analyzes the spatial-temporal distribution characteristics of bus passenger flow on weekdays and weekends in the study area,and to mine the spatial characteristics of station passenger flow changes.Secondly,using the complex network theory,the research identifies the key stations and classify the station areas through the station importance evaluation.The existing bus network topology model is constructed,and the structural characteristics of the network are analyzed from multiple perspectives;considering the network structure characteristics,spatial location characteristics and activity demand characteristics of bus stations,a multi-dimensional station importance evaluation index system is established,the weighted Technique for Order Performance by Similarity to an Ideal Solution(TOPSIS)algorithm is applied to identify the key stations in the network.On this basis,according to the station importance score,the K-means clustering algorithm is used to classify the station importance.Based on the evaluation results of station importance and the spatial location characteristics of stations,this paper uses Geohash spatial search algorithm to divide station areas into different levels.Then,the functional positioning of the station areas at each level is carried out,and the construction scheme of multi-activity aggregation areas is proposed to achieve the aggregation of travel demand in the area.Thirdly,this paper puts forward the method of hierarchical optimization of the public transport service network based on active guidance.Based on the station area,the OD agglomeration analysis of bus passenger flow is first carried out,and the key passenger flow is identified and graded.According to the idea of hierarchical optimization,the network is divided into three levels: high-frequency rapid transit routes,general bus routes and branch bus routes.The optimization model of each hierarchy of route network is constructed respectively,and the optimization object of high-frequency rapid transit routes is to maximum direct passenger flow density of the network,the optimization object of general bus routes is to maximum the network efficiency,and the optimization object of branch bus routes is to optimize accessibility of network.Then taking the passenger flow OD between station areas as an example,the hierarchical optimization design of the bus network is carried out,and the final multi-hierarchy bus network is obtained.And then the connection transport service of multiple-hierarchy public transport network is proposed.Finally,this paper evaluates the optimization effect qualitatively and quantitatively from multiple dimensions of line network scale,network structure characteristics,topology accessibility and passenger flow demand characteristics.This study takes the optimization method of public transport service network as the research object,from the perspective of residents’ daily activity travel demand,through in-depth analysis the characteristics of individual activity space and bus travel behavior,a multi-hierarchy public transport service network based on the coupling of station activity space and travel demand is constructed.Through the integration of service resources,the advantages of intensive public transport can be effectively play,which will be an active exploration to promote transformation of public transport development from “passive adaptation” to “active guidance”.