Study On Optimization Of Regional Highway Network Structure Based On Bilevel Planning Of Green And Coordinated Development

In the comprehensive transport highway traffic is of large volume,and sharing the most traffic volume,so the study of highway traffic structural optimization is particularly important.In the scale of development,the consideration of traditional scale forecasting method is based on the development of the road network itself,in the context of the development of integrated transport,in order to promote the efficient operation of road traffic and the whole transportation system,the scale and structure of the road network needs to be balanced with the integrated traffic scale;in the optimization of highway network hierarchical structure,the traditional hierarchical structure optimization is based on the targets of optimization like construction of highway transportation funds,the total saturation,capacity and so on,in the process of modernized transformation of road traffic and advance towards a high degree of modernization,the development of green transportation and the improvement of transport efficiency are becoming the core optimization target gradually.Firstly,this paper analyzes the needs for optimization in the upper scale structure of the highway network under the background of comprehensive traffic development.By analyzing the impact of different development stages on the development of the road network,it is found that the railway traffic is the transportation mode which has the greatest influence on the highway development scale in the integrated transportation system,also analyzes the transfer of traffic between the two modes of transportation.Second,by considering the difference of needs between the modernization and the high degree of modernization of highway,definite the optimization target of lower structure are carbon emission reduction and transport efficiency improvement,to lay the theoretical foundation for the subsequent hierarchical structure optimization model.The forecast of the reasonable development scale of the upper road network is analyzed from two angles.On the one hand,on the basis of the traditional forecast scale of highway development,the paper analyzes the influence of the separate two-child policy on the population size,the influence of the three industrial structure changes on the highway network coefficient,and the impact of urbanization on the scale of road network development,through improved land coefficient method,to predict the development of the current road network scale.At the same time,through the Markov transfer matrix analyze the highway,railway passenger and freight sharing rate transfer process,by using the Matlab software to solve the operation,and then put forward the average transport network as the operating parameters,to get the rational development of the road network scale,synthesize the prediction results of the two methods to determine the reasonable scale of the development of the road network.On the research and analysis on the optimization of Lower-level highway network grade Structure,first of all,by analyzing the different carbon emissions under different operating speed of different motorcycle type and different compositional ratio of different technical level motorcycle type,to get calculation formula of road carbon emissions under different levels;then select the appropriate input,output elements of road transport,analyze the efficiency of integrated highway transportation by DEA model,according to the provisions of Highway Engineering Technology Standard for the lower level of service level and V / C level of each grade highway,propose two adjustment criteria of high and low level based on saturation,determine the constraints of each grade highway mileage in the road network,then establish the multi-objective optimization model,and calculate the model by Matlab software.Finally,taking Linyi City Highway Network as an example,optimize the calculation according to the selected optimization target,to verify the practicality and maneuverability of road network scale prediction and hierarchical structure optimization based on green and coordinated development planning.