Network Layout Planning And Operational Strategy Optimization For Urban Transit System

Public transportation system plays a leading and supporting role in the rapid and sustainable development of cities,and has irreplaceable advantages in solving traffic congestion,environmental pollution and improving urban operation efficiency.After a decade of construction and development,the development of public transportation system has reached a bottleneck in some large and medium-sized cities in China,but the overall transportation efficiency and service quality of the system need to be improved.Under the background of the14^th Five-Year Plan and the development strategy of"Transport Power",the planning of public transport system needs to start from the overall situation,seek the meeting point of urban development and actual demand,balance the costs and benefits of travelers and operators,and complete the transformation from qualitative to quantitative,from local to overall.At the same time,the transit operational strategy also needs more flexible and fine design to adapt to the spatiotemporal heterogeneity of travel demand,to achieve the public transport system from"extensive"construction to"quality"upgrading transformation.To this end,this paper relies on the key projects of national Natural Science Foundation"Modern Urban Multi-modal Public Transport System Key Technology,Basic Theory and Performance"（51338003）and"Generalized Transport Hub City of Multi-modal Transport Network Collaborative Planning Theory and Method"（51638004）,focusing on the network layout planning and operational strategy optimization of urban transit system,and puts forward the following five aspects of in-depth research:（1）From the three levels of basic characteristics,model construction and solving algorithm,this paper sorts out and analyzes the theoretical basis of urban public transportation network planning,operational strategy optimization and bus passenger flow assignment,and makes clear the defects and deficiencies of the existing research framework,so as to provide the basis and basis for the follow-up research content.（2）A basic public transport network layout planning model is proposed.Under different public transport demand structures,planning standards and layout requirements,the model seeks to maximize the utility of the basic public transport network by starting with the two essential factors,which are the journey time and transportation efficiency of different public transport routes between OD pairs.Furthermore,this paper proposes a basic network layout planning algorithm applicable to different bus systems,such as common bus,bus rapid transit and rail transit,and verifies the effectiveness of the algorithm with a practical case.（3）With the objective of minimizing the generalized travel cost and operating cost,a multi-objective model of bus route and operating frequency planning is established.A cooperative coevolutionary multi-objective evolutionary algorithm（CCMOEA）was proposed.Two populations were used to evolve the transit route and operation frequency simultaneously,and reasonable and effective many-to-many combinations were explored to obtain the trade-off solutions between travelers and operators.The performance of the algorithm was verified by Mandl standard test network.（4）A bus line clustering method based on the similarity of demand structure is proposed to optimize the global operational strategy of bus lines in the same cluster,which not only considers the competition and collaboration among different transit lines,but also avoids the problem of low computational efficiency in the global optimization of large network.Moreover,the multi-objective optimization model of public transportation system operational strategy is constructed from the network level,and the cooperative coevolutionary multi-objective evolutionary algorithm and passenger flow assignment algorithm are further improved.The vehicle scheduling pattern and operation frequency of public transportation service are optimized collaboratively,and the effectiveness of the algorithm is tested through the experimental network.（5）Based on the"Tran Star"urban virtual transportation system,the overall framework and related functional modules are sorted out,and the necessary modules are redeveloped and recombined in series.Combined with the code implementation and function encapsulation of the above research contents,a complete simulation process from data acquisition and analysis at the input end to the implementation of the final scheme is formed.With real city cases as the research object,the transit network layout planning and operational strategy optimization of public transportation system are implemented and analyzed through the above simulation processes.