Study On Method Of Public Transport Development And Spatial Coordination Allocation In Small And Medium Cities Based On Mode Evolution

Public transport priority is the basic national policy of China,and Medium and small cities are main carriers of new urbanization.It is urgent to popularize public transport mode and spatial collocation method in medium and small cities.This paper is based on national funded key project “Basic Theory and Method of Integrated Design in Evolving Urban Model Road Transport System”(51238008)& “The Theories and Methods of Urban Multi Model Transport Network Collaborative Planning Based on Generalized Transport Hub”(51638004),and targets to achieve optimal space-time resource consuming in the city.Based on numerous research data three levels and two aspects are used in this subject.The three levels refer to: the macroscopical level in horizontal comparison between the vertical time evolution of the same cities and total travel characteristics in different years in different cities;the mesoscopic level in the construction of evaluation index system of urban space and public transport system;the microscopical level in analysis of coordination and optimization of conventional public transport and Bus Rapid Transit sharing operation.The two aspects refer to the coordination between urban space and public transport in mesoscopic aspect;the sharing coordination between Bus Rapid Transit and conventional public transport.First,study the evolution rule of travel of public transport in medium and small cities.Based on the analysis of travel characteristics of public transport in nine typical cities,establishing a model of the intrinsic relationship between key indicators such as bus sharing rate,bus travel time and macroeconomic factors of urban development,it is found that public transport rises up from subordinate position to the one of the main mode of travel gradually,and also its role is more and more prominent in commuter transport.The lower the economic level of cities,the trend of transition from non-motorized transport to public transport is more obvious.Once time consuming of mobility travel becomes longer,peoples’ tolerance towards time consuming of public transport will reach the highest point.Second,analysis the correlation between travel time consumption of urban public transport and urban macro-indicators.Through function fitting the relationship between travel time and travel volume and studying the correlation between different time-consuming interval and urban macro-indicators,it is found that the travel volume of residents in linearly is related to travel time consumption.The larger size of city,the more travel time consumed.When the travel time consumption is 60 minutes in big cities,more than half of the travelers choose public transport;when travel time consumption is within 40 minutes in medium and small cities,public transport sharing rate increases gradually and it will fall when time consumption is between 40 and 60 minutes.Large cities should establish long-distance public transport.medium and small cities are suitable for medium-distance.The share of public transport in the vast majority of small and medium cities is significantly lower than the computed value and its room for improvement is huge.Third,introduce urban bus rapid transit threshold.Based on the limitation of the overall space-time resources of the city,through the analysis of the resources and space resources in different ways,it is effective to reduce urban space-time resources and the travel time consumption of the residents by introducing bus rapid transit threshold.Then,study the method for evaluation of coordination between urban spatial form and urban public transport.Combined with the characteristics of medium and small cities,consider urban public transport,urban and rural public transport,rural public transport,bus types also consider the conventional public transport and bus rapid transit.Based on the coordination of technology,benefit,system and function,focus on the coordination of public transport itself and the coordination between spatial form and urban public transport,the evaluation index system is constructed.The subordinate concept in fuzzy mathematics is used to describe the coordination index and introduce weighting function optimally.A small city represented by Dan Yang,and a medium-sized city evolving into a big city and including bus rapid transit represented by Chang Zhou,is selected as a typical case.Relevant data of 8 years and the earlier are analyzed respectively for demonstration.Finally,study the method of coordinating sharing operation between bus rapid transit and conventional public transport.To improve the operation efficiency of bus rapid transit and conventional public transport in sharing road and stops,this paper proposes a shared operation coordination model and method based on the analysis of its operating characteristics.From two dimensions of time benefit and space benefit,the threshold of traffic volume of conventional public bus and social vehicles in three-lane(including one bus rapid transit lane)shared lanes is determined,analyzing the capacity and effective parking space of shared stops,obtaining the interrelationship between factors such as arrival rate of bus rapid transit,capacity of bus stop and number of lanes at the bus stop.Taking Changzhou BRT as an example,the effectiveness of the proposed optimization method for BRT and conventional buses is verified.