An evaluation of the road traffic system simulator PIMTRACS by PIM Original Research Article

The paper describes the development, structure and evaluation of road traffic control system simulator by PIM (PIMTRACS). PIM stands for parallel inference machine. It was developed under the close cooperation of Yaskawa Electric Corporation (Japan) and Flavours Technology Inc. (USA). It has an innovative architecture and excellent graphical user interface (GUI) environment. PIM is a computer system comprised of a number of parallel processor units called “cell” and global shared memory. The program assigned to each cell is called “tile” and is executed synchronously in a fixed cycle. The road traffic system is comprised of a number of elements or entities such as roads (lanes), traffic signals and vehicles. Each vehicle is regarded as an instance. Each instance is assigned to a tile in PIM and processed in parallel. In the simulation of a large scale road traffic system, the number of tiles required in the run is enormous, thereby demanding a large scale of PIM itself. Another problem is that we have to take into consideration how to optimise the assignment of instances to tiles. The paper aims at an effective description of microscopic traffic model of urban district and the analysis and problem solving of traffic congestion based on actual data. Our model is given in terms of one intersection for the time being. We intend to expand the traffic network scale, which will demand a larger scale of PIM. For example, as for the model with 10 intersections and 500 vehicles, approximately 1500 tiles are necessary, whereas for a model of 100 intersections and 5000 vehicles, 13,000 tiles are needed.