Study On Urban Traffic Forecast, Control And Route Guidance Based On VISSIM

Traffic network system is the pulse of building a city. The smooth operation of traffic network system will increase the travel efficiency of residents, leading to the high-efficient and sustainable development of city. However, the increasing traffic demand and urban traffic jams problem around the world restrict the development of city. Performing a scientific method of forecast, control and optimization on the state of urban traffic system operation will increase the level of urban traffic management. This paper further studies on traffic state forecast, travel time forecast, traffic route guidance and control. Models are built, including traffic state forecast and control model, gray travel time forecast model and traffic network route guidance model. A urban traffic control and route guidance system demo is also established. More details and conclusions are listed as follows.(1)Traffic state forecast and control model. Based on the concept of conservation of vehicles, traffic flow distribution characteristics and other traffic theories, this paper targets one-lane road and establishes a traffic state forecast model which is simple and practicable. Based on the data of forecast results, a one-lane road traffic control model is built as well. Through VISSIM simulation, it proves that the traffic state forecast model is able to forecast real-time traffic flow in short term and has a higher forecasting accuracy when it comes to congested traffic stream. It also demonstrates that the traffic control model is also reasonable and can alleviate traffic congestion problem effectively.(2)Gray travel time forecast model.This paper considers that travel time of every road has gray characteristic and two kinds of gray travel time forecast models are built, one is a model under normal driving conditions, the other is that under traffic accident. According to the result of VISSIM simulation, it is proved that the two gray travel time forecast models are reliable and able to forecast short-term travel time.(3)Traffic network route guidance model.Based on dynamic traffic network graph, this paper establishes the city traffic network route guidance model and gives steps of algorithm which is to solve gray dynamic traffic route guidance problem. It chooses a sector as a example which is adjacent to Shengtai road of Jiangnin district in Nanjing background and finishes the analysis. Through VISSIM simulation, it shows that the route guidance model is valid and able to provide effective decision support for traveling.(4)The development of traffic control and route guidance system demo.This paper designs general framework of urban traffic control and route guidance system based on the idea of ITS. Then it particularly presents three operation processes of the system, including traffic state forecast sub-system, traffic control sub-system and traffic guidance sub-system. A urban traffic control and route guidance system demo is finished using MATLAB.