Research On The Theory Of Aera Highway Network Planning And Its Application Of Traffic Planning In Qinhuangdao City

At present, in highway network layout two methods are mainly adopted, that is, gross control method and "four stages"method. And along with maturing of the theory,"four stage" method is adopted more and more by traffic planer. But traditional" four stages" method still exists a great many limits in itself, especially in aspect of traffic forecast. In forecasting of traffic generation, first appropriate forecast model must be built, moreover the key of building forecast model lies in establishing appropriate model. In the method of seeking solution of model parameter, least square method is mainly adopted. After that seek model function's derivative and sequentially approach parameter classic solution. But its velocity of seeking solution is slow and its error is large, at the same time classic solution is difficultly obtained. Sometimes some model functions' derivation doesn't exist. Presently in the aspect of traffic distribution forecasting, the equilibrium traffic distribution model that simulates realistic traffic condition still has no classic solution just because of its more parameters and great dimension. This cries for a new method that is used to seek for solution.In this dissertation, a fire-new idea is introduced in seeking solution model ?The popular artificial-intelligence search genetic algorithms is introduced in traffic engineering field, and it is used to seek solution of traffic forecast model.First, traffic forecast is the basis of extent highway-network layout, the existing traffic forecast model is reviewed in this paper, the shortcomings and localization of that model's solution in least square method is entirely analyzed. At the same time some genetic algorithms possess such features as random, entirely search, strong robust and trait of collateral calculation. Afterwards incorporation of genetic arithmetic and traffic forecast model is dissertated, and worked out C language program, that is applied in practice traffic layout's traffic forecast.Second, in the aspect of highway-network's appraise, in this paper author introduced highway network covering formation on basis of fractal theory, and have built up the fractal-based model of the covering formation of highway transportation network.Last, the authors applied area highway-network layout theory to actual traffic layout of Qin Huangdao city, and have taken very good practicality effect.