Interpretation ID: 2409y
Bureau of Safety Programs
Division of Traffic Safety
Illinois Department of Transportation
2300 South Dirksen Parkway
Springfield, Illinois 62764
Dear Mr. Wort:
This is in reply to your letter of March 27, l990, to Taylor Vinson of this Office with respect to Federal requirements for front side marker lamps on trucks. The Ford C-CT Series Cab is equipped with a reflex reflector (apparently mounted on the door, to judge by the Exhibit A that you enclosed), but does not have a separate front side marker lamp. Ford states that it uses "the roof mounted corner marker lamps to satisfy the side marker lamp requirements", and that they satisfy photometry and all other Federal requirements. You have asked whether "the top of the cab clearance light [may] be used to fulfill the requirements for front side market lights. . . on cab over engine vehicles."
The answer is yes. Federal Motor Vehicle Safety Standard No. l08, Lamps, Reflective Devices, and Associated Equipment, does not prohibit combining the front side marker lamp with any other lamp, and prohibits a front clearance lamp only from being optically combined with a front identification lamp (section S5.4, formerly S4.4). Although, under Table II of Standard No. l08, Location of Required Equipment, a front side marker reflector may not be mounted higher than 60 inches from the road surface, there is no corresponding limitation on the mounting height of front side marker lamps, which would preclude it from being located on top of the cab. The marker lamp must be located "as far to the front as practicable", and the agency generally defers to the manufacturer's discretion in determining whether a location is practicable, unless it is clearly erroneous. Judging by the location of the combination clearance-side marker lamp shown in Exhibit A that you enclosed, we have no reason to question Ford's decision to locate the lamp there.
I hope that this answers your question.
Sincerely,
Stephen P. Wood Acting Chief Counsel
/ref: 108 d:4/25/90