OPPORTUNITIES FOR IMPROVED TRANSPORTATION PLANNING.

The approaches, technical procedures, and analytical methodologies utilized for urban transportation planning need to be improved if the intent of the 1990 amendments to the Clean Air Act is to be achieved. Approaches to managing the growth in travel demand need to become a routine component of strategically-based transportation plans. Transportation control measures generally result in total benefits that exceed their costs, and can serve as an effective supplement to stationary, area, and other forms of mobile source air quality strategies. Current methods of developing highway vehicle emission inventories generally lack the ability to produce the degree of spatial and temporal disaggregation desired by air quality analysts. The four-stage urban transportation analysis process was developed to support the construction of major new fixed transportation facilities, and does not easily interface with air quality analysis needs. In summary, today's standard transportation planning practices are not good enough for air quality purposes; there is a need to move towards today's best practices while simultaneously undertaking efforts to improve the overall state-of-the-art.