%0 Journal Article
%A Thomas P Wenzel
%A Brett C Singer
%A Robert R Slott
%B Journal of Transportation and Statistics
%D 2000
%N 2
%P 1-14
%T Some Issues in the Statistical Analysis of Vehicle Emissions
%U http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/journal_of_transportation_and_statistics/volume_03_number_02/index.html
%V 3
%2 LBNL-46115
%8 09/2000
%X <p>This paper presents some of the issues that complicate the statistical analysis of real-world vehicle emissions and the effectiveness of emissions control programs. The following issues are discussed: 1) inter- and intra-vehicle emissions variability, 2) skewness of the distribution of emissions from in-use vehicles, 3) the difficulty of obtaining statistically representative vehicle samples, 4) the influence of repeat testing on only a subset of the vehicle fleet, and 5) differences among common test methods and pollutant measurement devices. The relevance of these issues is discussed in light of three regulatory purposes: testing the compliance of in-use vehicles with certification standards, evaluating the effectiveness of vehicle inspection and maintenance programs, and estimating emissions inventories for air quality modeling and compliance planning. A brief history and description of common vehicle emissions tests is also provided.</p>