Interpretation ID: 86-6.19

TYPE: INTERPRETATION-NHTSA

DATE: 12/22/86

FROM: ERIKA Z. JONES -- CHIEF COUNSEL NHTSA

TO: DALTON G. FEAGLER

TITLE: NONE

ATTACHMT: LETTER DATED 07/16/86, TO ADMINISTRATOR -- NHTSA, FROM DALTON G. FEAGLER

TEXT: Dear Mr. Feagler:

This is in reply to your letter of July 16, 1986, to the Administrator, with respect to your "Dee-Tailer" device, asking for confirmation that it complies with Motor Vehicle Safety Standard No. 108.

SAE Standard J586c Stop Lamps, August 1970 incorporated by reference in Standard No. 108, in essence defines a stop lamp as one that indicates the intention of the operator of a vehicle to stop or to diminish speed by braking. Although you intend your device to indicate a similar intent, it would operate the stop lamp at any time the accelerator was released regardless of whether the driver intended to apply the brake pedal. This could result in confusion to following drivers. The "Dee-Tailer" could therefore be viewed as impairing the effectiveness of the stop lamp within the prohibition of Paragraph S4.1.3 of Standard No. 108, and hence, unacceptable as an item of original equipment.

With respect to the aftermarket and the permissibility of your device for used vehicles, the National Traffic and Motor Vehicle Safety Act prohibits a manufacturer, dealer, distributor, or motor vehicle repair business from rendering inoperative in whole or in part equipment that is installed in accordance with a Federal safety standard. Thus installation of the "Dee-Tailer" by a person other than the vehicle owner could be considered a violation of the Act. Finally, the acceptability of the device would also depend upon the laws of any State in which it is to be sold or used.

In concluding that the center highmounted stop lamp was the most effective way to reduce the incidence and frequency of low speed rear end collisions, the agency considered deceleration warning devices such as "Dee-Tailer," and found no discernible benefit from their use.

We appreciate your interest in motor vehicle safety.

Sincerely,