Mr. Melissa Brooke
Safety & Compliance
ICI International Carriers (Tilbury) Inc.
42 Mill Street West
Dear Ms. Brooke:
This responds to your letter concerning Federal Motor Vehicle Safety Standard (FMVSS) No. 108, Lamps, Reflective Devices, and Associated Equipment. You stated that you would like clarification on additional factory installed lamps that are in a horizontal line with the required cluster of three amber identification lamps. You stated that the lamps in question would not be spaced at a distance that is at least twice the distance that separates each lamp in the required cluster, and would be on a separate switch from the cluster. As discussed below, it is our opinion that such a design would not be permitted by FMVSS No. 108. You also asked whether this would be a violation of 49 CFR 391.11(d) if the additional lamps remained off while a vehicle was in the United States. As that regulation was promulgated and is enforced by the Federal Motor Carrier Safety Administration (FMCSA), we are referring that question to that agency.
By way of background, the National Highway Traffic Safety Administration (NHTSA) is authorized to issue FMVSSs that set performance requirements for new motor vehicles and items of motor vehicle equipment (see 49 U.S.C. Chapter 301). NHTSA does not provide approvals of motor vehicles or motor vehicle equipment. Instead, manufacturers are required to self-certify that their products conform to all applicable safety standards that are in effect on the date of manufacture. FMVSS No. 108 specifies requirements for original and replacement lamps, reflective devices, and associated equipment.
In your letter, you requested clarification on additional factory installed lamps that are in a horizontal line with the required cluster of three amber identification lamps. You added that the lamps in question are not spaced at a distance that is at least twice the distance that separates each lamp in the required cluster. Based on your description, this lamp design would not be permitted by FMVSS No. 108.
We have explained in past interpretation letters that additional lamps placed in the vicinity of and in a horizontal line with the required cluster of three identification lamps impair the functioning of the identification lamp cluster, and are therefore not permitted by FMVSS No. 108. We have also explained that this problem is avoided if the additional lamps are spaced at a distance of at least twice the distance that separates each lamp in the identification cluster. Because the lamps you describe are in the horizontal line with the identification lamps, and are not spaced far enough apart from the cluster, they are not permitted by FMVSS No. 108. The fact that the lamps would be on a separate switch from the required cluster would not change this result, as the lamps would impair the effectiveness of the required lamps whenever they were turned on.
You also asked a question about 49 CFR 393.11(d). Specifically, you asked if the additional lamps placed on a separate switch from the identification cluster remained off while the vehicle was in the United States, whether there would be a violation of section 393.11(d). Again, we are referring that question to FMCSA.
If you have any further questions about NHTSAs regulations, please contact Ari Scott of my staff at (202) 366-2992.
Anthony M. Cooke
 See 4/26/07 letter to Kim D. Mann (copy enclosed). In that letter, for example, we stated that a product would impair the effectiveness of the identification lamps by obscuring the three-lamp cluster pattern required by the Standard, rendering it unrecognizable by turning it into an eleven-lamp cluster.
 See 7/28/05 letter to Robert M. Clarke (copy enclosed).