Interpretation ID: nht78-3.25

DATE: 10/02/78

FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA

TO: Thomas Built Buses, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your August 25, 1978, letter asking what the term "normal nighttime illumination" mean in Standard No. 217, Bus Window Retention and Release.

The term "normal nighttime illumination" is found in paragraph S5.5.2 of the standard. This section requires that all interior exit instructions be legible when the only source of light is the normal nighttime illumination of the vehicle. The term, as used in this paragraph, means that exist instructions must be visible with the normal interior vehicle lighting that is in use when the bus is moving. Interior vehicle lighting may include, for example, reading lamps and overhead lights.

SINCERELY,

Thomas BUILT BUSES, INC.

August 25, 1978

Office of the Chief Counsel U.S. Department of Transportation

Attn: Roger Tilton

Subject: MVSS 217, Section S5.5.2 - School Bus

Dear Mr. Tilton:

We are inquiring if a definition has been given to the phrase "Normal Nighttime Illumination".

Our interpretation is that the interior lights in the vehicle constitude "Normal Nighttime Illumination".

We are most interested in hearing from you in this matter.

James Tydings, Specifications Engineer