This report documents and presents a top-level design and implementation plan for geographic information systems (GISs) for transportation. The basis for the design and implementation plan has been first an assessment of the current state of the art of GIS for transportation (GIS-T) through interviews with DOTs and MPOs and through a survey of GIS vendors, and second a projection of technological developments through the next five to ten years. A GIS-T may be thought of as a union of a GIS and a transportation information system, with enhancements to the GIS software and to the transportation data. A central significance of GIS-T technology is in its potential to serve as the long-sought data and systems integrator for transportation agencies. Given that so many transportation data are or can be geographically referenced, the GIS-T enabled and managed concept of location provides a basis for integrating databases and information systems across almost all transportation agency applications. In order to realise the greatest benefits of GIS-T, DOTs should develop agency-wide strategic plans that comprehend not only GIS technology adoption and application, but also concurrent adoption and application of open-systems standards and of a wide range of imminent complementary technologies, from computer networking and distributed computing, through new data storage media and database architectures, through computer-aided software engineering, to computer-based graphics and computer-aided design. The plans should address a full range of application scales, because GIS has the potential to become ubiquitous throughout all functional areas of transportation agencies. The recommended approach is top down for system design, then bottom up for application development. A GIS-T server-net architecture with computational and data management labour divided among different kinds of servers is recommended. (Fifteen kinds are suggested as a plausible first iteration for the required design.) Implementation of the server net can be incremental with a conceptual architecture in place as an organising principle before complete physical realisation is feasible, just as the concept of location can serve as a conceptual integrator for data schemas before the GIS enabled and managed spatial databases required for actual integration are fully available and as they are being incrementally constructed. (A)
Abstract