PLANiTS (Planning and Analysis Integration for Intelligent Transportation 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 deliberation 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 Systems 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 methodology will likely expedite the implementation of intelligent technologies by systematically examining their trade-offs with more conventional transportation improvement actions. PLANiTS’s structure, functionality, 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 performance 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 different locations can communicate by sending and receiving messages and sharing the planning vector. Users at different locations can examine and review the results and iterate in an open and deliberative planning environment. Overall, PLANiTS facilitates transportation planning processes by combining analysis and deliberation.