Brittleness Theory Of Complex Systems In Road Traffic System

With the improvement of people's living standard, the ratio of per capita car in our country has increased year by year, thus making traffic jams congestion problems arise in many cities. At the same time, with the sharp increase in automobile, accidents have frequently occurred in our country every year, which causes serious harm to people's safety and national economy. Therefore, the effective and timely control over the urban road traffic accidents is full of the realistic significance.Urban road traffic system is a typical and complex system. Traffic accidents can stimulate the brittleness of traffic system, which leads to the collapse of the traffic system. With the large scale of urban road traffic system expandsd, the brittleness problem of traffic system is becoming more complicated. Once the brittleness of a traffic system is activated, it will bring serious damage to the whole system.Therefore, analyzing the causes of brittleness being motivated, the mechanism and the control of brittle source,has become an urgent event.The paper shows the importance of the study of complex systems brittleness by introducing the development of complex systems. Then, follows the definition,features and graphic description of complex systems brittleness. Based on the further study on the set pair analysis theory and the entropy thoery, the paper preserts the basic concepts of brittleness risk entropy of traffic accident.Secondly, based on the set pair analysis theory, the paper shows the brittle source level of traffic system. First of all, we should first establish the brittleness model of the urban road traffic system. The main idea of the established model is to give the inflow and outflow of a junction at any moment. We use the number of vehicles this moment to reflect how crowded the road is, which is the extent of collapse of the junction. And the paper shows a particular example to illustrate the method of determining the level of brittle source.After the brittle source level of the various factors of traffic system is decided,the paper mainly focuses on the factors of traffic system, and the analysis of accident entropy of traffic accident system. By analyzing the factors of causing to the road traffic accidents with practical examples of traffic accidents in 2006, we have found the brittleness factors of the brittle traffic system. By reducing the accident entropy,we make the effective control over the brittle source and find appropriate path to control it.Finally, by introducing Analytic Hierarchy Process, the paper redefines the rate of calculation based on the original consequences entropy function, thus making the consequences entropy function more reasonable. Besides,it is applied to the road traffic system,helps conduct respective numerical simulation and analyze the the experimental results.