Study On Distributed Large-scale Microscopic Traffic Simulation

As the research about traffic simulation constantly goes deeper, the simulation accuracythat researchers required becomes more and more higher, such as the truth degree of models’interaction, the accuracy of the simulation results and the operability in the simulation process,and so on. Furthermore, with the constantly increase of social need, the simulation of roadnetwork is no longer confined to the traffic simulation of a single intersection or some certainroads, but developing in the direction of large-scale rode network and complicate control. Itmakes the simulation workload to increase exponentially, and the traditional serial algorithmcouldn’t meet the simulation requirement. Although there are some super computers cansatisfy the simulation requirement, but the expensive cost becomes a important obstacle for itspopularization.Parallel technology gradually rises with the development of computer, and it provides aneffective means for solving the large-scale computing. Through the parallel technology,connecting the multiple computers in the LAN as a whole by the switches and other network,and each computer can achieve mutual coordination and complete the whole computing of aprogram. Parallel technology is introduced in the traffic simulation, and this technology canassign the whole simulation computing as certain principles to each computer of a cluster, andcomplete the simulation commonly by all of the computer. By this way, it not only can realizethe simulation of large-scale rode network, but improve greatly the simulation efficiency andthe utilization ratio of CPU.Firstly we conduct a feasibility analysis of parallel technology on the microscopic trafficsimulation in the study, to ensure the parallel traffic simulation technology can achieve theexpected function. Secondly, through comparative study of several parallel popular libraries,such as MPI, PVM, OPEN-MP, and so on, we summarize their advantages and disadvantages,and choose the best parallel libraries of this traffic simulation-MPI. Because there are a largenumber of mature domestic traffic simulation model in foreign country, through researchingthis models and algorithms, and combined with ours actual traffic characteristics, we build amore consistent model of the traffic situation, and build a master-slave simulation frameworkin accordance with the characteristics of MPI. By analysising the entire large-scale road network data and cluster hardware configuration, researching the division of the roadnetwork method, we divide the entire net work by the processor and then the processcomplete the coordinate calculation in parallel. In the process we study of the correlation ofsimulation and parallel algorithms in-depth: achieve the basic model of traffic simulation,such as the car-following model, and so on; design a parallel master-slave model based onMPI; through analysising the large-scale road network, we research into the methods ofdividing road network, and the process can achieve the main message collection andtransmission of messages between subnets. Finally, we analysis the results of simulation, andverify the parallel computing technology in traffic simulation acceleration effect.