Geographic Information Systems (GIS) are a powerful tool for efficiently managing and integrating the myriad types of data necessary for the planning, design, construction, analysis, operation, maintenance, and administration of transportation services and facilities. NCHRP Report 359, "Adaptation of Geographic Information Systems for Transportation," provides an overview for applying the GIS concept to transportation (GIS-T). A summary of state efforts in GIS-T circa 1990 is presented in NCHRP Research Results Digest 180. A management guide is published as NCHRP Research Results Digest 191.

Administrators, engineers, and researchers are continually faced with transportation problems on which much information exists, often in the form of reports, computer data, and undocumented experience and practice. Because of the complexity of many transportation issues, both within and across modes, the information required to fully consider the various alternatives frequently resides in a number of units within local, state, and federal agencies and is not readily available for use in the decision process. Geographic information systems (GIS), which have been successfully applied in many fields outside of the transportation industry, offer the potential to assemble and process data from a diversity of sources and present it in an easily understood graphical format. A GIS is a computerized data management system that is designed to capture, store, retrieve, analyze, and display spatially referenced data. The capabilities of a GIS in the transportation field, referred to as GIS-T, would permit the assimilation, integration, and presentation of data collected and stored by each of the divisions within a highway agency.

The research involved (1) identification and assessment of current and planned activities in the design, development, implementation, and operation of GIS-T; (2) development of GIS-T concepts and technologies (including definitions of GIS-T, GIS-T structures, internal and external system components and relationships, analytical tools, standardization issues, data conversion and maintenance, map scales, location referencing methods, accuracy/precision issues, use of expert systems, and system outputs); (3) definition of areas of application (e.g., accident analysis, hazardous material routing, highway performance monitoring systems, planning, project management, socioeconomic and environmental impact); (4) formulation of a design for a GIS-T with a detailed description of the associated concepts and technologies; (5) identification of GIS-T implementation issues; and (6) preparation of a management guide to assist transportation agencies in the implementation of a GIS-T.