Use of models to establish source-receptor relationships and estimate relative source contributions of NO_x to air quality problems

A basic objective of the Technical Symposium on the Implications of a Low NO_x Vehicle Emission Standard is to examine the need for and technical feasibility of a low NO_x emission standard for future light-duty motor vehicles. A major component of this assessment is to estimate the changes in air quality that would result from the imposition of a low NO_x vehicle emission standard. Such an assessment requires a method for relating emission to air quality changes, i.e. a so-called air quality model. In this summary, we focus on those air quality models that may be used to estimate the impact of changes in the NO_x emission levels from motor vehicles