A MANUAL OF REGIONAL TRANSPORTATION MODELING PRACTICE FOR AIR QUALITY ANALYSIS. VERSION 1.0

Recent changes in the context of transportation planning have increased the importance of regional transportation analysis methods. In particular, the Clean Air Act Amendments of 1990 set forth requirements for detailed planning and analysis which apply to many states and metropolitan areas. This Manual, prepared for the National Association of Regional Councils as part of NARC's Clean Air Project, was designed to help transportation planning agencies, including metropolitan planning organizations (MPOs), state departments of transportation, and other entities, respond to the issues raised in carrying out transportation modeling for air quality planning efforts. The Manual reviews transportation modeling today, focusing primarily on travel demand forecasting as it is practiced by regional agencies, and suggests strategies for responding to specific analysis needs and for overcoming common problems. The emphasis is on identifying issues which MPOs should consider in reviewing their models, and on recommending sound options for addressing such issues in accordance with local objectives and resource availability. Several of the topics covered in the Manual are in a state of flux (e.g., analysis procedures for conformity determinations). As a result, the Manual is in loose leaf notebook format to facilitate periodic revisions and updates. The Manual is organized in five chapters, as follows: (1) Introduction; (2) The Emerging Context of MPO Analysis; (3) Current Analysis Practice; (4) Matching Analysis Tools with Analysis Needs; and (5) Looking to the Future. There are two appendices: (A) Glossary and (B) References.