The Analysis Of Regional Road Net

Comparing in respect of transportation process, relative ratio of passenger and freight transport quantum, coverage area, reachability, etc., a regional highway network is not only the basis for human activities, like economy and society, and urban evolution, but also a major transportation means of a regional comprehensive transportation system. Starting from systemability and operationability and abiding by the research method combining the macro with the micro, the qualitative with the quantitative, the partial with the whole, this dissertation adopts basic theories and mathematic ways like economics, spatial geography, planning science, graph theory, etc., and makes an all-encompassing analysis of a whole range of matters involved with highway network, such as influencing factors, system structure, element connection, etc. The main contents of this research are listed as follows:(1) A regional highway network is an organic combination of nodes (towns) and lines (routes). This dissertation analyzes its formation, development, conformation, network system, and infers the developmental mode and self-resembling growth process of highway networks depending on both external and internal driving forces, and proves the positive relativity between highway grade and traffic capability, as well as the trend of structural evolution that the number of highway routes is increasing.(2) Based on multi-disciplinary intersection and systematic philosophy of analysis, this dissertation discusses the relationship of urbanization level and developmental level of highway networks, and establishes a model of coupling coordination level, and researches the spatial matching proportion between town system and highway network with the consideration of the spatial layout of regional town system.Also, considering the mutually acceleration and rising spiral-type interaction process which is demonstrated by the decisive influence of economy on highway network and the boosting effect of highway network to the economy, this dissertation puts forward a balanced matching function of economy and highway network, and deduces an interactive relationship between the evolution of economic spatial structure and the highway network.(3) Usually, the actual scale of highway network does not reflect its ability to accomodate and adapt to transportation needs. Then, a way to calculate the capability scale of highway network is presented to emphasize the synchronous improvement of quantity and quality. Consequently, a model of target planning for optimization of network grade structure which meets confining conditions such as needs, total volume, structure and investment can be established.By classifying highway network into three grades and basing the function nature and hiberarchy of the highway network, this dissertation classifies highway functions in regard to different hiberarchy network, and undertakes function selection and positioning of routes with the consideration of the internal composition of highway transportation passages and the factors influencing route functions. After analyzing the conformation characteristics of highway network from different points of view, such as coverage level, spatial connection way, topology structure and real-dimensions, this dissertation calculates and ranks the importances of nodes, also determines the conformation of highway network using regional network entropic value.Moreover, this dissertation improves the method of transportation regional route layout for the objective of coverage node importance, and compares route importances and vectorial angles and then presents a method of importance layout in which line elimination forms multiple circuits network. It evaluates quality of highway network layout using circuity rate, reachability and connectedness level, and represents connection reliability of highway networks with related matrixes, and describes reliability of operation state with traffic time, volume, straightway reliability, etc.(4) This dissertation defines composite nodes and classifies them into different grades. In view of spatial ranges of cities, it compares adaptabilities of different connection methods, calculates development speeds and grades of cities and matches grades of highways with those of the nodes, and optimizes connection of highways to nodes. Since there are many differences between highways and urban roads, this dissertation analyzes the connection locations of highways to urban ring roads, the standards and intervals of three-dimensional intersections, the buffering sections of vehicle speed and transection of plane intersections, and the intermingle of transition sections of highways to urban roads.(5) In regard to problems like low road speed, road surface damages, waste of road space, frequent traffic accidents, etc., coming from the mixed passenger and freight transportation, this dissertation defines parallel expressways, compares passenger and freight seperated route transportation and mixed transportation in aspects of average road speed, traffic capability, economic benefits, traffic accidents, and establishes an objective function and needs confining conditions for function configuration of expressway systems.Altogether, the research content of this dissertation covers influencing factors, system structure and matching elements of highway network. The author hopes that it may be of some reference value for accelerating the theorization, standardization and scientification of highway network planning, construction and management in our country and improving adaptability of highway network to accomodate with comprehensive transportation, economic development and town systems, and increasing supply ability of highway networks.