Microcosmic Traffic Flow Modeling And Simulation Based On Multi-Agent

Multi-Agent system has been used to solve the problem of traffic guidance from macroscopy. The traffic flow model based on Multi-Agent system and driver attributes is set up in this paper, in which the car-agent model is the most importance part. This study focuses on some significant parameters: driver attributes and car-type, that make this model distinct with other studies. Besides, the negotiations between car agents reflect the car-agents' motives and beliefs including the parking negotiation, lane negotiation and changing-lane negotiation. Based on this frame model, three traffic scenes are simulated in the following chapters in which the driver attributes functions and the decision-making models are instantiated according to the traffic environment. These scenes have typical character of abnormal traffic, so these simulations are benefit for the study of traffic collision. Three scenes are as follows:(1) Cars' Crossing Willfully to Traffic Flow based on Multi-agent System.Multi-agent system is used to describe the behavior of cars' crossing willfully when they are not on the crossroad. Moreover, the driver attributes are considered as important parameters to each agent, and some models are proposed. To get the effect of the cars' crossing willfully, we set simulations that depict cars cross road with some probability. According to the results, there are some conclusions as follows: first, car tracing cauda is more frequent when the flux is larger. Second, when the probability of crossing is small, it rarely influences flux. Once the probability of crossing exceed 0.015, it is necessary to set some traffic signal to warning the crossing drivers. Third, as far as driver attributes, the number of accident is increased with the ratio of slowness driver increasing; besides, the flux decreases.(2) A Multi-Agent Model for Evacuation System under Large-scale Events.The model of Chapter 2 is instantiated and used to simulate the large-scale activity. Car's variability is introduced by superimposing agents, with different driver's activity agenda, motives and beliefs. In the large-scale events, there are three sub-models which based on the multi-agent model: the park model, the evacuation- road model and the normal-road model. After above three phases, traffic flow time space dissipation models under large-scale activity are analyzed, moreover, investigated data of traffic flow under large-scale activity dissipation are used to test the accuracy and applied example of these models, such as the flux of some investigation site, the evacuation time of audience. The results show that these models have small errors about forecast and can reflect the changing of traffic flow after large-scale events, which might be helpful to traffic management scheme.(3) The effects of road maintenance in the freeway system.The normal model, lane maintenance model and overtaking lane maintenance model are proposed. After simulating, we analyze how the driver attributes, car types and the position of maintenance signal influence on the traffic flow and collision. The results show that: the driver attributes have relationship with traffic collision under low flux, but it has little influence on the form of collision as a whole. Besides, the effect of car types and the position of signal to collision are obvious. It had better not maintain the lane if the flux is between 0.1 and 0.2, and the big-vehicle proportion is 0.4. When it comes to overtaking lane, it had better not maintain when the flux is 0.25 and the big-vehicle proportion is low. Moreover, the maintenance signal should have a reasonable position according to the flux.Based on three models' simulations and analyses, some advice and traffic parameters are proposed, and they might helpful to the traffic management and traffic evacuation.