This paper is about the transportation planning process--the public-sector analog to the investment decision-making process of the private sector. The paper's purpose is to identify the looming informational deficits in measuring the impact of transportation on regional economic health, in estimating the revenues available to finance transportation system development and operation, and in evaluating transportation alternatives. The paper examines the informational requirements of the transportation decision process. The process is viewed as a hierarchy of policies, programs, and projects. The paper first describes how transportation economists believe the decision process should function, identifying the analytic steps and key informational requirements of the process. It then goes on to identify key deficits in the informational resources that are available to decision makers and provides draft research statements in key areas.