PLANiTS (Planning and Analysis Integration for Intelligent Trans- portation Systems) is a process-based computer system that supports a series of mutually interdependent steps progressing toward developing and programming transportation improvement projects. It is a tool that translates problems and goals to performance measures, examines possible competing and complementary transportation improvement actions, systematically evaluates the impacts of actions using models and knowledge, and supports human interactions between stakeholders. The PLANiTS methodology is nonincremental because it integrates existing knowledge about transportation with analysis using models with delib- eration and issue resolution. To link planning and modeling, PLANiTS has a policy base that contains contemporary performance measures, an action base containing conventional and Intelligent Transportation Sys- tems actions, a methods base that facilitates modeling, a case that has qualitative and quantitative information about historical cases, and a set of computer-based communications tools. This comprehensive method- ology will likely expedite the implementation of intelligent technologies by systematically examining their trade-offs with more conventional transportation improvement actions. PLANiTS’s structure, functional- ity, and application are described. Transportation improvement projects are represented as planning vectors in PLANiTS. A vector permits users to examine the effects of chosen transportation actions in terms of per- formance measures within an environment. Users must specify the actions, performance measures, and the environment, each in terms of their spatial, temporal, and user dimensions. Then they can analyze the planning vector with models and case-based reasoning. During the process of planning vector specification and analysis, stakeholders at dif- ferent locations can communicate by sending and receiving messages and sharing the planning vector. Users at different locations can exam- ine and review the results and iterate in an open and deliberative plan- ning environment. Overall, PLANiTS facilitates transportation planning processes by combining analysis and deliberation. Urban transportation problems persist and are increasing in their complexity and scope. Traffic congestion, pollution, and safety prob- lems are a part of daily life. Whereas these problems may be accept- able at certain levels, their current levels are high. Lawmakers have approved legislation such as the Intermodal Surface Transportation Efficiency Act (ISTEA) and the Clean Air Act to curtail the harmful effects of travel and to fund projects that address broader policy goals. New transportation technologies offer solutions to these prob- lems; however, inappropriate technology implementation can some- times worsen them. Therefore, a planning methodology that seeks to address important transportation problems needs to be open and policy-relevant. Although new transportation technologies offer opportunities, there is a gap between their development, assessment in a specific context, and proper implementation. Importantly, in transportation planning, there is a complex and often muddled political process that precedes the implementation of transportation projects. The “plan- ning problem” is made complex by the difficulty of involving vari- ous stakeholders in transportation project planning, the intricacy of the analytical processes, the lack of systematic knowledge bases, and the difficulty of setting up real-time deliberative and negotiation processes. To implement intelligent transportation technologies, a key ele- ment is being able to identify Intelligent Transportation System (ITS) opportunities in the planning process. It is likely that intelligent trans- portation technologies will not dominate the planning process. Rather, they may act as catalysts for change. Any new planning methodology should permit stakeholders to examine trade-offs among ITS and con- ventional transportation actions, evaluate impacts and benefits, and sharpen insights in an interactive environment. The implementation of new transportation technologies is complicated partly because they must be eased into the existing transportation system. This often pro- motes the status quo and encourages incrementalism—hampering innovative new approaches. However, to address problems compre- hensively, any new planning methodology must enhance creativity in exploring innovative solutions. To support the emerging transportation planning processes and facilitate ITS implementation, a new planning methodology should integrate the structured methods (i.e., transportation planning and operational models) with semistructured analysis techniques such as knowledge-based systems and unstructured electronic deci- sion support. A methodology called PLANiTS, which stands for Planning and Analysis Integration for Intelligent Transportation Systems, was proposed for this purpose (1,2). Whereas structured analysis and modeling have been used widely in transportation plan- ning, their integration in an open and deliberative planning envi- ronment supported through computer dialogue is an innovation made possible by PLANiTS. To address transportation problems, PLANiTS offers expanded opportunities for considering alternative strategies (e.g., synergies among new technologies). The earlier work focused on developing the conceptual structure for PLANiTS (1,2). This paper reports on structuring of PLANiTS concepts and their translation into a practical tool that can support a real-life trans- portation planning process. The planning support comes from being able to run sophisticated models and access quantitative and quali- tative information through case-based reasoning and intelligent data bases. Importantly, stakeholders can make transportation plans interactively in PLANiTS. 32 Paper No. 970362 TRANSPORTATION RESEARCH RECORD 1588 PLANiTS Structuring and Supporting the Intelligent Transportation Systems Planning Process ASAD J. KHATTAK AND ADIB KANAFANI A. J. Khattak, Department of City and Regional Planning, University of North Carolina, Chapel Hill, N.C. 27599. A. Kanafani, Institute of Trans- portation Studies, University of California, 109 McLaughlin Hall, Berkeley, Calif. 94720.