The HIPERTRANS (High Performance Transport Network Modelling and Simulation) project is developing a simulation tool that will provide a new range of facilities for road transport consultants, traffic engineers and urban traffic control centre (UTC) managers. Through the application of a low cost but high performance computing environment, advanced simulation technologies and industrial software production methodologies, a fast, representative, flexible and visually comprehensive traffic simulation tool is available. This tool will have a major impact on the work of road traffic consultants and policy makers who will be able to rapidly assess and visualise the effects of new strategies and policies in the management and planning of urban road networks. The activities of traffic engineers in developing new control paradigms can be enhanced and supported by the simulator's ability to link to a UTC in real time and behave in the same way as a specified road network. This will allow street conditions to be examined when controlled by different strategies or algorithm settings and the different results compared. The requirements for the HIPERTRANS simulation and prediction tool have been analysed to produce a system specification which forms the basis for a detailed system design. The design is being implemented to deliver three versions of the HIPERTRANS system: prototype simulator, S1; real time simulator, S2; and predictor, S3. The simulators are targeted towards testing of traffic control systems by stimulating them with a wide range of potential traffic scenarios in order to safely evaluate their behaviour.