Report on the Scope and Methodology of FMCSA's Review of Canadian/Mexican Compliance with Federal Commercial Motor Vehicle Safety Standards (FMVSS)
On September 24, 2008, as required in Section 4139(b) of the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users, we issued our report on the scope and methodology used in Federal Motor Carrier Safety Administration’s (FMCSA) April 2006 Review of Canadian/Mexican Compliance With Federal Commercial Motor Vehicle Safety Standards (FMVSS). Our audit objective was to provide our observations of the scope and methodology FMCSA used in its review.
Our audit found that while the review provided evidence that most vehicles sampled complied with FMVSS, the estimates subsequently formulated based on the sample were not statistically valid because of how the sample was selected and projected. Additionally, the quantitative impacts of key assumptions are not clearly presented for report users to effectively evaluate the estimates made. According to FMCSA, the concerns raised may be valid, but FMCSA does not expect that the reported findings are significantly affected by them. Additionally, FMCSA agreed to the two recommendations that focus on actions FMCSA needs to take to ensure that any future FMVSS compliance reviews include appropriate review by a FMCSA statistical expert and that results are clearly presented.