Interpretation ID: nht79-3.42

DATE: 12/31/79

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: American Motors Corporation

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your recent letter requesting an interpretation of the warning system requirements for seat belts in Federal Motor Vehicle Safety Standard No. 208. The buckles of driver lap belts in all AMC vehicles and most Jeep vehicles are equipped with switches that prevent the audible belt use warning system from operating when the driver turns the ignition on after having fastened his or her lap belt. You ask whether the standard allows removal of the switch and associated wiring. The effect of this step, which would result in a savings of about $ 1.50 per vehicle, would be that the warning would operate regardless of whether the driver has fastened his or her lap belt. You also ask that your letter be considered a petition for rulemaking if this removal is not permissible.

Paragraph S7.3 of the standard requires a seat belt warning system that activates a 4 to 8-second warning light when the vehicle's ignition switch is moved to the "on" or "start" position (condition "a"), and a 4 to 8-second audible signal when condition "a" exists and the driver's lap belt is not fastened (condition "b"). Under your proposal, the audible signal would be activated when both conditions exist. However, it would also be activated when condition "a" alone exists.

The functioning of the audible signal when condition "a" only exists is not permissible under the standard. The rulemaking notices which led to adoption of the current requirement stated that the agency's intent was that the audible signal operate if the driver's lap belt is not in use. The agency expressed that same intent in the standard by specifying the light was to function when condition "a" existed and the audible signal when both conditions "a" and "b" existed. To interpret the standard to permit the signal to operate when condition "a" only existed would be to render purposeless the specification of condition "b".

Further, the agency denies your petition to amend FMVSS 208 to permit operation of the audible signal when condition "a" only exists. A greater limitation was placed on the operation of the audible warning signal in consideration of the irritation factor associated with the signal but not with the light. To provide a reminder and incentive for safety belt use and to avoid subjecting the conscientious belt user to having to hear an audible reminder to do something that he or she has already done, the agency specified that the signal would not function if the driver's safety belt were fastened.

In light of studies concerning the value of a properly designed belt use warning system in improving the rate of belt use, the agency is contemplating including a proposal to amend the FMVSS 208 warning requirements when it issues its forthcoming notice of proposed rulemaking on seat belt comfort and convenience. We would welcome your views on the proposal following its announcement.

Sincerely,

ATTACH.

November 19, 1979

Joan B. Claybrook -- Administrator, National Highway Traffic Safety Administration, U.S. Department of Transportation

Dear Ms. Claybrook:

This office is evaluating the feasibility and legal implications of a proposed product improvement. We are considering removing the driver's lap-belt buckle switch and associated wiring harness from the seat belt use reminder system currently installed on all AMC and most Jeep vehicles. We believe that eliminating this buckle switch would not detract from the effectiveness of the reminder system.

The lap-belt buckle switch functions to deactivate the audible signal when the driver's restraint system is fastened. We are of the opinion that the effect of its removal would be consistent with the law as stipulated in paragraph S7.3 of 49CFR571.208 and section 125 of the National Traffic and Motor Vehicle Safety Act, as amended.

Additional support for our opinion that the audible signal need not be belt-use sensitive apparently can be found in the preamble to Docket 74-39; Notice 3, the final amendment to FMVSS 208 which adopted the new reminder system requirements. In that notice, the NHTSA noted that its initial proposal had intended that the audible warning should be dependent on belt use, but that after consideration of comments received, the Agency determined that "Because of the limited benefit, the reminder should be provided at as low a cost as feasible." Therefore, the NHTSA "determined that an audible-visual combination will provide the best reminder at a cost commensurate with the benefits achievable in a limited-duration signal."

The removal of the lap-belt buckle switch would be consistent with these stated objectives. The achievable associated cost reduction is estimated to be approximately $ 1.50/vehicle, and because many, if not all, U.S.-marketed cars use designs with a similar buckle switch, an industry-wide potential savings of $ 15 million per year appears reasonable.

The resultant belt use reminder system would operate the same as today except that both the light and buzzer would activate for 4 to 8 seconds each time the ignition is turned on regardless whether the driver's belt is fastened. Such a system would not likely be judged unacceptable by the motoring public because we believe that the majority of belt users "buckle up" during the time that the reminder system is activated by the operation of the ignition switch. Therefore, the termination of the audible-visual signal would be essentially coincident with the occupant's fastening of the restraint system.

We ask for your prompt concurrence that such a reminder system would be consistent with Federal requirements. The timeliness of your response is important as the potential product savings and consumer price benefits could be realized almost immediately. Because this is a component deletion that does not require design or tooling time, we could implement this change soon after we receive a favorable response.

If you determine that our interpretation of the belt-use reminder system requirements is not correct, we ask that this request be considered as a petition for rulemaking to amend FMVSS 208 such that the audible signal may be, but is not required to be, driver belt-use dependent.

Sincerely,

K. W. Schang Director - Vehicle Safety Programs -- AMERICAN MOTORS CORPORATION