James A. Haigh, Vice President
Technical Specifications & Application Development
7205 Sterling Ponds Court
Sterling Hts., MI 48312
Dear Mr. Haigh:
This responds to your letter regarding whether your product, the Transpec Merge Alert, is permissible under Federal Motor Vehicle Safety Standard (FMVSS) No. 108, Lamps, Reflective Devices, and Associated Equipment. Specifically, the Merge Alert is an LED (light emitting diode) device that mounts on the rear of a transit bus, and alternatively flashes in amber lights the word Merging, as well as a Yield sign or an arrow. As discussed below, we do not believe that such a device would be permitted under FMVSS No. 108 if installed as original equipment on a motor vehicle. Furthermore, we believe that it would be a violation of 49 U.S.C. 30122 if the Merge Alert were installed by a manufacturer, dealer, distributor, or motor vehicle repair business.
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. NHTSA selects a sampling of new vehicles and equipment each year to determine their compliance with applicable FMVSSs. If our testing or examination reveals an apparent noncompliance, we may require the manufacturer to remedy the noncompliance, and may initiate an enforcement proceeding if necessary to ensure that the manufacturer takes appropriate action.
New motor vehicles are subject to the requirements in Standard No. 108 regarding flashing lamps. The question of which lamps are permitted to flash on a vehicle is addressed in paragraph S5.5.10 of FMVSS No. 108. The relevant provision states:
The wiring requirements for lighting equipment in use are:
(a) Turn signal lamps, hazard warning signal lamps, and school bus warning lamps shall be wired to flash;
(b) Headlamps and side marker lamps may be wired to flash for signaling purposes;
(c) A motorcycle headlamp may be wired to allow either its upper beam or its lower beam, but not both, to modulate from a higher intensity to a lower intensity in accordance with section S5.6;
(d) All other lamps shall be wired to be steady-burning.
In general, flashing lamps are prohibited on vehicles under S5.5.10(d), unless they fall into one of the exceptions listed in S5.5.10(a)-(c). Because the Merge Alert does not fall into any of the lamp categories covered in sections (a)-(c), it is subject to the general prohibition on flashing lamps of S5.5.10(d). Therefore, the Merge Alert could not be installed on transit buses as an item of original equipment or installed on a vehicle by its manufacturer or dealer prior to the initial sale of the vehicle for a purpose other than resale, as it would be a violation of Standard No. 108.
Also, S5.1.3 of Standard No. 108 prohibits the addition of equipment on a vehicle if it impairs the effectiveness of lighting equipment required by Standard No. 108. As we have explained to you in previous letters, while there are limited exceptions, we interpret the standard as generally prohibiting electronic message boards because they have the potential of impairing the effectiveness of required lighting. The primary concern is that such devices can distract other drivers sharing the roadway from understanding and responding to the lighting devices required by Standard No. 108. For example, given that your product would be mounted on the rear of a transit bus, it could distract other drivers attention from the required turn signals. While we have recognized a limited exception for school buses, i.e., we defer to the States with respect to the narrow issue of prescribing or prohibiting electronic message boards (including flashing message boards) on school buses, we do not recognize such an exception for transit buses. Also, non-standard signal lamps are generally prohibited by this provision due to the potential to cause confusion.
If sold as aftermarket equipment, the Merge Alert would be treated differently. Paragraph S3, Application, of FMVSS No. 108, defines the type of equipment and vehicles that Standard No. 108 applies to. Part (c) of that paragraph applies to [l]amps, reflective devices, and associated equipment for replacement of like equipment on vehicles to which this standard applies. [emphasis added] Because the Merge Alert is an auxiliary lamp that does not replace a like item of motor vehicle equipment, Standard No. 108 is not applicable. Therefore, the requirements of Standard No. 108 would not prohibit the sale of the Merge Alert as aftermarket equipment.
However, Federal restrictions would still exist with respect to the installation of the Merge Alert. Under 49 U.S.C. 30122, if an item of equipment is installed by a "manufacturer, dealer, distributor, or motor vehicle repair business," that equipment as installed must not "make inoperative" any of the required safety equipment. As NHTSA has stated in previous interpretations, if an item of motor vehicle equipment impairs the effectiveness of lamps required by Standard No. 108, we consider that to have made the lighting system inoperative, and therefore the installation of that equipment would be a violation of 30122 if performed by a manufacturer, dealer, distributor, or motor vehicle repair business. Therefore, it would be a violation of 30122 for any of these entities to install the Merge Alert on vehicles other than transit buses, even if it was purchased as aftermarket equipment.
We note that 30122 applies only to manufacturers, dealers, distributors, and motor vehicle repair businesses. Therefore, if an electronic message board, such as the Merge Alert, is installed by a vehicle owner, without assistance from a manufacturer, distributor, dealer, or motor vehicle repair business, the owner is not violating Federal law if (s)he installs it and uses it.
Furthermore, States regulate auxiliary lighting equipment in various ways. We suggest that you contact State agencies to ascertain the legal status of the Merge Alert with regard to State regulation.
If you have any further questions, please contact Ari Scott of my staff at (202) 366-2992.
Anthony M. Cooke
 See also our discussion below of flashing message boards on school buses.
 These letters are available on NHTSAs website at http://isearch.nhtsa.gov/.
 We note that we do not interpret Standard No. 108 as prohibiting signs on the front of new transit buses showing the destination, although the standard does limit the color of the lamps for such signs. See our October 19, 2006 interpretation to New Flyer, also available at http://isearch.nhtsa.gov/.