Interpretation ID: 1983-1.7

TYPE: INTERPRETATION-NHTSA

DATE: 01/26/83

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: Blue Bird Body Company

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of December 7, 1982, to Mr. Vinson of this office asking for an interpretation of Motor Vehicle Safety Standard No. 108 with respect to a new option for school buses permitted by Wisconsin. This option would allow two additional red lamps, front and rear, as a supplement to the red warning lamp system required by paragraph S4.1.4(a) of the standard.

As a general rule, supplemental lighting is permitted by Standard No. 108 as long as it does not "impair the effectiveness of lighting equipment" required by the standard (paragraph S4.1.3). In our opinion, the separate lamps that would be permitted by Wisconsin on the front of the school bus, between the bottom of the windshield and the top of the highest headlamp, would not impair the effectiveness of the front lighting equipment. The lamps on the rear, however, according to Wisconsin, could be incorporatedn "in an existing lamp" provided that such incorporation "shall not interfere with or override the existing unit's function." We believe that the language both of Standard No. 108 and the Wisconsin specification would effectively prohibit incorporation of the warning lamp into the stop lamp of the school bus. However, we believe that this language would allow its combination with the tail lamp, or its addition as a separate lamp.

We trust that this is responsive to your request.

SINCERELY,

BLUE BIRD BODY COMPANY

December 7, 1982

Taylor Vinson Department of Transportation National Highway Traffic Safety Administration

Dear Taylor:

I am writing for an interpretation of FMVSS 108 based on the attached copy of the new Wisconsin School Transportation Specifications. You will note that Wisconsin is asking for an additional warning light on each side, front and back, tied into the existing warning light flasher system in order to make school buses more visible to vehicular traffic.

It is the opinion of Blue Bird that this does not affect the requirements of FMVSS 108 providing the basic requirements of this standard are not altered by the addition of the additional two (2) lights front and rear.

I am looking forward to your prompt response.

Thank you.

Thomas D. Turner Manager Engineering Services

C: DEWEY BRUNNER; JIM MOORMAN

Wisconsin School Transportation Specifications

(a) The bus shall be equipped with alternating red flashing lamps.

1. The bus shall be equipped with 2 red warning lamps at the rear of the vehicle and 2 red warning lamps at the front of the vehicle, which shall be controlled by a manually actuated switch and shall flash alternately at rate of 60 to 120 cycles per minute. A brake or door operated switch shall not be permitted. The "on" period shall be long enough to permit bulb filament to come up to full brightness.

a. An option is permitted, whereby, 2 additional alternating flashing red lights may be mounted on both the front and rear of the bus. The additional front facing lights shall be located between the bottom of the windshield and the top of the highest headlamp. They may be mounted on the fender or the cowl.

b. The additional rear facing lights may be separate lamps mounted within 12 inches above or below the directional turn signals or may be incorporated in an existing lamp. Any incorporation with an existing unit shall not interfere with or override the existing unit's function.

c. The optional system shall have units with a red lens of at least the same diameter as the required alternating lights. The alternating "on," "off" positions shall be opposite from those of the required alternating lights. The effect will produce the required top mounted flashing light and an optional mid-height mounted light to flash on opposite sides simultaneously. The result can be described as a "wig-wag" or "cross-arm" effect.

2. The red warning lamps shall be of seal beam construction or other improved type such as strobe, not less than 5 inches in diameter and visible from a distance of at least 500 feet along the axis of the vehicle in bright sunlight.

3. There shall be a visible or audible means of giving clear and unmistakable indication to driver when the signaling system is turned on.

4. Each red warning signal lamp shall be mounted with its axis substantially parallel to the longitudinal axis of vehicle.

5. The front and rear red warning signal lamps shall be spaced as far apart laterally as practicable, and in no case shall the spacing between lamp centers be less than 3 feet.

6. The front red warning signal lamps shall be located so that they can be clearly distinguished when headlamps are lighted on lower beam.

7. The warning signal lamps shall be mounted at the front above the windshield and at the rear so that the lower edge of the lens is not lower than the top line of the side window openings.

8. The front and the rear signal lamps shall be unobstructed by any part of the vehicle from 5 degrees above to 10 degrees below horizontal and from 30 degrees to the right and 30 degrees to the left of the centerline of the vehicle.

9. The area around the lens of each alternately flashing red signal lamp and extending outward approximately 3 inches shall be painted black on all school buses. This subdivision shall not apply to vehicles not specifically manufactured as school buses and which have red warning signal lamps mounted above the roof top. Red warning signal lamps on such vehicles shall be equipped with black hoods at least 3 inches long.

10. Except as provided in sub. (9) above, red warning signal lamps may be equipped with hoods to shield from rays of sun for improved visibility.