Research On Analysis And System Configration Of External Passenger Corridor In Megalopolis

Demand and supply are two complementary aspects in transportation system. While traffic demand is the starting point and basis for all transportation issues, supply is the direct and fundamental expression of demand. With the development of transportation planning, demand analysis has advanced a lot in our country, however, systematic research of supply configuration has been in lack both home and abroad. The simple configuration scheme based on "average daily passengers in a year" cannot effectively respond to demand under current massive statistics. Therefore, it’s necessary to explore the systematic configuration which corresponds to demand analysis.Setting background in China’s current systematic configuration conditions and megacity external passenger corridors where serious conflicts lie, this article explores the characteristics of systematic supply and demand structure for megacity external passenger corridors, and builds a preliminary theory and method framework for external passenger corridors. Main contents are as the following:Systematic and scientific mindset and methods are used to define the megacity external transportation system, as well as to analysis systematic elements and the environment, the corridor evolution mechanism, and the boundary and category of corridors. Based on the trip characteristics on the traffic cross section, the method to determine the start and end points of external passenger corridors is developed; and on the basis of differed trip intentions, the way to distinguish between long and short corridors in external transportation system serving the regional transportation is introduced.Relationship among demand, supply and transportation structure of comprehensive transportation corridors is identified and analyzed. And the conflicts between individualized trip intentions and collective transportation supply are determined to be the underlying cause for all transportation problems. This article further claims that transportation system configuration is a process in which random demands are expressed and met by limited and ordered supply, it also uses the entropy theory to identify transportation objectives as to increase entropy under currently supply conditions and to maximize expressed corridor demand. Besides, this article also states that due to the fact that transportation demand is structured, it’s important to meet the demand as well as match the structure.The demand analysis methods for urban external transportation are reviewed and summarized. Systematic analysis on aggregated features such as aim, time, distance and space distribution of trips is introduced against those characteristics of urban external transportation, and impacts of different distribution on the choices of vehicles are discussed. Besides, this article introduces "default cost" to define basic and non-basic trips, and uses probability theory and physicalistic psychology to build a time-value analysis model of different trip aims.Effects and costs characteristics of corridor supply methods are analyzed from the perspective of the entire trip process in combination with method chain features. A method to analysis transportation mode features, which is based on traffic time/capacity fluctuation adaptability and space distribution adaptability, is introduced.Principles to govern the systematic configuration of city transportation corridors are introduced, and with the aim to meet as much as possible transportation demand with corridor supply, the paper devises a dynamic planning method to get supply and demand of transportation corridors matched, which is based on a OD matrix and consists of a double-layer system of "large feedback loop" and "small feedback loop". The preliminary structure of sub-models such as the theory model of vehicle selection, spatial cluster analysis model, and supportive decision-making model of vehicle selection, are introduced on the basis of factors such as differed trip intentions, space distribution of trips and effectiveness of transportation covering etc. This paper also offered some simple applications of the theories in the real world.Using "trip demand structure" instead of "trip volumes " as the basis of transportation corridor configuration, this article discusses the entire chain from demand structure of transportation corridors to supply characteristics and how to match them, in order to provide some help for configuring our cities’external passenger corridors during a period emphasizing on balanced supply and demand.