With the rapid development of China's national economy, the number of urban motor vehicles has increased year by year, and the utilization and development of urban land has also brought about changes in urban layout and environment, leading to increasingly serious urban traffic congestion and chaos. In order to effectively improve the utilization rate of urban roads and solve the traffic congestion problem, it is necessary to scientifically analyze the traffic conditions of urban roads and find out reasonable improvement measures. As an important means of traffic optimization design, microscopic simulation of traffic flow can simulate and analyze traffic conditions from intersection design, traffic flow organization and channelization, signal control and other aspects, get evaluation results in time with less cost and time investment, and put forward the best scheme to improve traffic conditions. 1 Introduction to Simulation Technology 1 1 System simulation is to imitate the real system and study an existing or designed system through experiments on the system model. System simulation is a new technical science, and its description of the system is based on the mathematical model. However, because the establishment and solution of mathematical models of complex things and complex systems are more and more restricted by conventional mathematical models, system simulation came into being as a means to solve such complex problems. At present, with the progress of computer technology, system simulation technology has been widely used at home and abroad, especially in the fields of aviation, aerospace, petroleum, chemical industry, transportation, ecology and other engineering systems, which has promoted social progress and scientific and technological development. 1.2 computer simulation due to the limitation of related technical conditions, the initial stage of system simulation is mainly physical simulation, that is, the physical model of the object is established under a certain proportion. With the development of simulation technology and computer software and hardware technology, system simulation has gradually developed from physical simulation to mathematical simulation, and the dynamic process and operation law of the system are revealed by studying the motion behavior of the system. The digitization of physical objects is mainly realized by computers, so mathematical simulation is also called computer simulation. Compared with traditional physical simulation, modern computer simulation can solve many complex problems that cannot be solved analytically by mathematical means, preview or reproduce the motion law or process of the system, and simulate the system that cannot be directly tested, thus saving a lot of energy and expenses. Simulation can be divided into time-driven simulation and event-driven simulation according to different implementation methods, that is, whether the simulation process control is based on time control or event control. Time-driven simulation is to scan the system state at intervals according to the computer clock, set an appropriate time as a step, calculate the variable values of all state elements of the system according to the simulation model, and update the input or output accordingly. Event-driven simulation takes the occurrence of predetermined events as the standard to determine the input and output of updates. 1.3 traffic microscopic simulation Traffic simulation is a technology to reproduce the temporal and spatial changes of traffic flow. It also analyzes complex traffic phenomena by establishing a mathematical model of traffic system, which belongs to the category of computer digital simulation. According to the description degree of simulation model, traffic simulation can be divided into macro simulation, micro simulation and micro simulation. Traffic microscopic simulation describes the individual characteristics of the system, and reflects the overall characteristics of the system by truly reflecting all the individual characteristics of the system. Computer traffic microscopic simulation generally takes one or several groups of traffic flows as the research object, describes the dynamic situation of all vehicles in each step value with time drive, and displays it in the form of images or animations. Compared with the traditional traffic analysis technology, the traffic microscopic simulation technology has obvious advantages: the description of the change law and interaction of the basic elements in the system by the simulation model closely corresponds to the actual operation process of the system, which is conducive to forming a flexible model mechanism; Modeling unit is the most basic traffic element in the traffic system, such as vehicles, lanes, traffic lights and so on. Therefore, microscopic traffic simulation is more flexible and accurate in describing actual traffic behavior. Traffic microscopic simulation technology can directly describe the dynamic traffic state of the road network, and the traffic analysis results are generally displayed in the form of animation, which is convenient for interaction with users and has strong openness. The role of traffic micro-simulation is too long, so I can't finish it here. Please contact me at 5450696 1.