||Approaches to Analyzing Data from the Portland Study, Task 4.
Lai, Larry S. L. ;
Gins, John D. ;
||Technology Service Corp., Santa Monica, CA.;Environmental Protection Agency, Ann Arbor, MI.
Air pollution ;
Exhaust emissions ;
Motor vehicles ;
||Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy.
The EPA is currently conducting the Short Test Correlation and Effectiveness Study (Portland Study), a large-scale emission testing program, in Portland, Oregon. For all the vehicles involved in the study, vehicle emissions are measured by three short tests (STs) at a state inspection station and by the three tests plus the Federal Emission Certification Test Procedure (FTP) at an emission testing laboratory. The two basic areas of interest in the Portland Study are: (1) the issue of association of short-test emissions (as measured in areal-world inspection/maintenance environment) and FTP emissions; and (2) theoretical and practical questions concerning the process of inspection and maintenance. The purpose of this report is to provide various sound statistical procedures that could be used in analyzing data from the Portland Study.