Interpretation ID: 1983-3.24

TYPE: INTERPRETATION-NHTSA

DATE: 11/22/83

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: Peterson Manufacturing Co.

TITLE: FMVSS INTERPRETATION

TEXT:

Mr. Paul Scully Vice President Peterson Manufacturing Co. 4200 East 135th Street Grandview, Missouri 64030

Dear Mr. Scully:

This is in reply to your letter of October 25, 1983, to Mr. Cavey of this agency asking for a copy "of an NHTSA ruling issued sometime ago which supposedly permits the triple identification lights normally mounted on the top rear center line of semi-trailers to be mounted at the lower sill location."

I enclose a copy of an interpretation furnished the State of Wisconsin on June 18, 1981, concerning this practice by Fruehauf Corporation. In summary, Fruehauf demonstrated to us the impracticability of mounting the lights at the top of a body with high-opening doors and a narrow header (chiefly because of vulnerability of the wiring).

The agency's interpretation was limited to vehicles of that specific configuration, and was not intended to apply to semi-trailers in general.

If you have any further questions, we shall be glad to answer them.

Sincerely,

Frank Berndt Chief Counsel Enclosure

October 25, 1983

Mr. Kevin Cavey Crash Avoidance The National Highway Traffic Safety Administration 400 Seventh Street SW Nassif Building Washington, DC 20590

Dear Kevin:

At the recent SAE Lighting Committee meetings, there was some discussion of an NHTSA ruling issued sometime ago which supposedly permits the triple identification lights normally mounted on the top rear center line of semi-trailers to be mounted at the lower sill location. Frankly, I was rather surprised at this and had not been aware of any such ruling. Most of the industry now feels that the NHTSA has granted the trailer industry permission to mount these triple identification lamps at the lower sill level rather than at the top most part of the trailer which had previously been required.

I would very much appreciate it if you could send me a copy of the reference letter which had been discussed granting permission for these lamps to be mounted at the lower heighth.

Since the rear clearance lamps are now normally mounted in combination with the turn signal lamps at the lower rear of the trailer, these identification lights were really the only high mounted lamps required on the rear of the trailers and they served well to indicate that a heavy, over 80" vehicle was on the highway. If these lights are permitted to be mounted at the lower level, the following drivers will have absolutely no means of knowing that a large, heavy-duty vehicle is in front of them. If information I have received is correct, in a few years time we have gone from these five high mounted lights on the rear of semi-trailers to no lighting at the top of the trailer. Obviously, a vehicle directly behind the trailer could block all access to the lower lights and a following driver, except the one directly behind the trailer, would have no way of knowing the vehicle was even there. I am quite surprised that NHTSA would grant such an exception on a permanent basis and therefore I would very much appreciate a copy of that so-called ruling which I understand has been issued.

Very truly yours,

Paul Scully Vice President

cc: Don Armacost, Jr. Joe Hodges