Research And Implementation Of Simulation Based Dynamic Traffic Assignment Model

There are 4 main parts in this paper: research on simulation based dynamic traffic assignment model and algorithm, research on dynamic traffic assignment based traffic forecasting model and algorithm, basic parallel algorithm research,software development and data testing.Simulation based dynamic traffic assignment research is the most important part of the whole paper. Based on literature review and problem analysis of dynamic traffic assignment, with the purpose of applying dynamic traffic assignment into ITS, this paper designs a multi-mode simulation intersection discrete vehicle simulation model. Relationship between travel time and traffic flow can be obtained from this model. This model can provide information including path selected and travel time on each link for each vehicle; intersection delay, inner delay and departure delay of each intersection, traffic flow on links and travel time, all the optional paths and average travel time. Also this model has high single-core and parallel efficiency.Then this dynamic transportation assignment model is applied onto dynamic traffic flow forecasting. And basic model and extended model are provided. These two models can deal with computation efficiency and precision respectively and can be brought into practical use. After that, this work explores parallel initialization of dynamic transportation assignment. And parallel dynamic assignment algorithm and network split algorithm are given. Parallelism of this model is also analyzed.At last, the simulation model promoted in this paper is implemented by software development, and detailed algorithm and data structures of main modules are developed. To improve efficiency of implementation, C++ language is used for software development. The program includes 19 classes and 21 data structures, 251 functions and 8000 lines of code. Integrality of the model and perfection of the development are shown by tests on several small network samples and real data of road network of Yingkou city. Data such as time consuming of single-core implementation illustrates that simulation capacity and efficiency of the model is enough for practical use.