TOWARD IMPROVED REGIONAL TRANSPORTATION MODELING PRACTICE

This paper is the first product of the National Association of Regional Councils' Clean Air Project and is intended to stimulate discussion about the short- and long-term future of regional travel demand modeling in the U.S. Its intended audience includes metropolitan planning organizations, Federal and State transportation agencies and regulators, environmental organizations, academic experts, and other concerned individuals. The paper explains why the status of regional modeling has become a hotly-debated transportation planning issue, identifies a set of perceived model inadequacies that should be addressed in the near future, reviews a number of technical questions that likely will require additional research and development, and flags procedural and institutional issues that may arise if model-based analyses are accorded a greater role in urban transportation decision-making.