METHODOLOGY FOR EVALUATING HIGHWAY AIR POLLUTION DISPERSION MODELS

This report describes the development and application of a comprehensive methodology for assessing the performance of dispersion models used to estimate highway-related air pollution. Specifically, the goals of the study were to: Develop methods for evaluating the performance of highway air-pollution dispersion models; Assembel and document a data base to be used to assess model performance; and Demonstrate the application of the model evaluation procedure by performing a preliminary evalaution of selected models. The report is organized into seven chapters and seven technical appendixes that include mathematical derivations and user's guides to the software and data base. The findings of the study are discussed in Chapters Two through Four. Chapter Two describes the development of the statistical methodology. Sensitivity analysis is discussed in data base. The application of the methodology is described in Chapter Five. Conclusions and recommendations are given in Chapter Six. Chapter Seven contains an extensive bibliography of model evaluation methods. Appendixes A through D describe the mathematical details of the statistical methodology. Appendixes E and F, respectively, contain user's guides to the computer programs that calculate the evaluation statistics and that perform the diagnostic analysis. The user's guide to thee data base is given in Appendix G.