Interpretation ID: nht78-2.45

DATE: 01/06/78

FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA

TO: Arent, Fox, Kenter, Plotkin & Kahn

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your December 1, 1977, request for agreement by the National Highway Traffic Safety Administration that the installation as original or aftermarket equipment of an electric retarder on the driveline of an air-braked vehicle would not affect its compliance with Standard No. 121, Air Brake Systems.

Section 108(a)(1)(A) of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. @ 1397(a)(1)(A)) requires, among other things, that no person manufacture or sell any motor vehicle manufactured on or after the date any applicable Federal motor vehicle safety standard takes effect unless it is in conformity with such standard. As your letter indicates, you are aware that this provision makes it impossible for the NHTSA to "approve" the compliance of a vehicle configuration in advance of manufacture of the vehicle, because there can be no certainty that the vehicle as manufactured will actually comply. In this case, for example, the retarder's weight or the manner in which it is mounted would affect the actual compliance of the vehicle in which it is installed.

Jacobs' September 20, 1977, analysis evaluated the likelihood that certain retarders to be imported or manufactured by Jacobs would affect compliance. With regard to these retarders, it appears that their installation as original equipment or in the aftermarket in the fashion described would not affect compliance of the vehicle with Standard No. 121. This finding is of necessity limited to the retarders evaluated in the September 20, 1977, analysis.