The SAPPORO project deals with the research and development of a knowledge-based urban road traffic modelling and management system. It integrates within a unique object-oriented architecture various tools and modules for network design, geometric layout, network object editing, interactive rule-based signal plan construction, qualitative modelling and simulation of traffic, floating car simulation and an Actor-based contract net architecture for distributed traffic control. In contrast to existing solutions SAPPORO aims at a homogeneous representation of knowledge throughout the design, modelling, simulation and control process by relying on four basic paradigms: objects (class-based multiple inheritance), rules (for signal plan construction, qualitative inference engine), qualitative reasoning (macroscopic traffic model) and Actors (distributed control, floating cars). The prototype system has been developed over the last two years and has actually been tested by using a standard microscopic traffic simulator (MISSION). This paper describes the concepts of the prototype system, the graphical user interface and discuss the accuracy of the qualitative traffic model. (A)
Abstract