Comment on Kahane

April 9, 2004 Dr. Jeffrey Runge, Administrator National Highway Traffic Safety Administration U.S. Department of Transportation th400 7 Street, S.W. Washington, D.C. 20590 Comments on NHTSA Technical Report, Vehicle Weight, Fatality Risk and Crash Compatibility of Model Year 1991-99 Passenger Cars and Light Trucks (DOT HS 809 662), Docket NHTSA-2003-16318 Dear Dr. Runge: Public Citizen welcomes the opportunity to comment on the recent technical report by National Highway Traffic Safety Administration (“NHTSA”) researcher Charles Kahane, Vehicle Weight, Fatality Risk and Crash Compatibility of Model Year 1991-99 Passenger and Light Trucks, a revision of an earlier 1997 NHTSA report also by Kahane. The new study, like the former one, examines the effects of hypothetical changes in vehicle weight upon fatalities. While we applaud the agency’s increased investigation of vehicle compatibility — not just in this report but in other NHTSA studies as well — we are very concerned about this study’s methodological flaws, problematic assumptions, and unexplained, implausible results. The key flaws in the new study: 1) Kahane’s study confounds vehicle size and weight, making no attempt to model the influence of weight changes independent of size despite the fact that other researchers continue to demonstrate the feasibility of such modeling. 2) The study looks at the wrong issue: size and design, not weight, actually matter most for ...