Mr. Daryn Tubbergen
    Midwest Regional Sales Manager
    Sound Off Inc.
    5132 37th Avenue
    Hudsonville MI 49426

    Dear Mr. Tubbergen:

    This is in reply to your letter of September 16, 2002, and enclosed videotape, asking for confirmation of your conclusion that the "Anti-Blow-By Secondary Warning Light System" (referred to in this letter as "the System") you describe is not prohibited by Federal Motor Vehicle Safety Standard No. 108. The System is intended for use on school buses. My staff has reviewed the videotape and commented that it would have been clearer had there been a narrative as to what exactly was being depicted at any given moment, since your brief written description of the System is at times at odds with the videotape.

    The System has three variants. "System 1 Anti-Blow-By" consists of four lamps of no specified color (your video tape shows that they are red strobe lamps), two mounted on the front of the bus above the bumper and two on the rear, above the bumper. You stated that when the red lamps of the school bus warning system are activated, the four lamps "will turn on and will flash." Your video tape shows that they flash twice for each single flash of the required red school bus signal lamps; also they alternate in phase with red school bus signal lamps.

    The specifications for school bus-specific lighting systems are set forth in paragraph S5.1.4 of Standard No. 108. This requires a school bus to be equipped with either four red signal lamps, or four red and four amber signal lamps designed to conform to SAE Standard J887, School Bus Red Signal Lamps, July 1964. The school bus system must be wired so that the amber lamps are activated only by manual or foot operation, and, if activated, are automatically deactivated and the red signal lamps automatically activated when the bus entrance door is opened.

    Your System is not part of a red and amber school bus warning lamp system, even though it is wired to operate simultaneously. Even though you may believe that the System is supplemental to the required red school bus signal lamps, it is not, because the System does not function identically nor is it located as prescribed by SAE Standard which is referenced in S5.1.4. It flashes twice for every single flash of the required lamps. Although paragraph S5.5.10(a) specifically requires that the red and amber school bus warning lamps be wired to flash, paragraph S5.5.10(d) requires that all lamps (other than those enumerated in S5.5.10(a)-(c)) be steady burning. This requirement applies to your System 1, which would be prohibited because it flashes.

    We also call your attention to S5.1.3, which prohibits the addition of motor vehicle equipment that impairs the effectiveness of lighting equipment required by Standard No. 108. Because your lamp system is mounted lower than permitted for school bus warning lamps, we believe your system may impair the effectiveness of required lamps on the rear of the school bus. This is because school bus warning lamps are required to provide at least twice the intensity as the maximum permitted intensity of red rear stop and turn signal lamps.

    "System 2 Anti-Blow-By with Brake Function" consists of a pair of supplemental stop lamps that are caused to flash in the manner identical to System 1 when the school bus signal lamps are operating. .

    System 2 also would not be permitted by S5.5.10(d) because it flashes.

    "System 3 Side Warning Lights" consists of two lamps "to be mounted on either side of the bus around the stop arm area . . . ." While not clearly described in your letter or video tape, we presume that these lamps operate in a manner similar to System 1, but with the lamps facing directly to the side near the front of the bus, presumably to warn drivers in vehicles on cross streets. As such, System 3 would not be permitted by S5.5.10(d) because it flashes.

    If you have further questions, you may refer them to Taylor Vinson of this Office (202-366-5263).


    Jacqueline Glassman
    Chief Counsel