Action
Interpretive rule.
Summary
This document sets forth our interpretation of the location requirements for identification and clearance lamps mounted on the rear of trucks and trailers whose overall width is more than 2032 mm (80 in.). Federal Motor Vehicle Safety Standard No. 108 requires that identification lamps be mounted as close to the top of a vehicle as practicable. The identical requirement applies to clearance lamps, except when the rear identification lamps are mounted at the extreme height of the vehicle. In the past, we have stated that the manufacturer may make the initial determination as to whether it is practicable to mount these lamps near the top of a vehicle, and that it has been our enforcement policy to accept the manufacturer's determination of practicability unless that decision appears clearly erroneous. Under this approach, identification lamps on many vehicles, especially van-type trailers, have been mounted on the lower sill below the rear doors under various conditions, even on vehicles where the header was up to 3 inches wide. Our enforcement policy was based in part on the unavailability of narrow lamps. However, narrow lamps are now readily available. Effective on the publication of this interpretive rule, we interpret Standard No. 108 to require manufacturers to satisfy an objective standard of practicability; i.e., if, under all the circumstances, it would be practicable to locate lamps above the rear doors, the manufacturer must do so. We will no longer defer to a manufacturer's subjective determination of practicability.