Interpretation ID: nht81-3.44
DATE: 11/30/81
FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA
TO: K. G. Moyer
TITLE: FMVSS INTERPRETATION
ATTACHMT: 4/1/88 (EST) LETTER FROM MICHAEL FINKELSTEIN TO CARL KAPLAN (STD. 108); 3/7/88 MEMO FROM ERIKA JONES; 5/2/84 LETTER FROM FRANK BERNDT TO LAWRENCE F. HENNEBERGER
TEXT: This is in reply to your letter of September 22, 1981, about your "alert device which automatically turns on the stop lamps of the vehicle when the accelerator is released." You wish our permission to install the device for experimentation and testing on other vehicles, as well as an interpretation of Federal Motor Vehicle Safety Standard No. 108 whether your device is allowable.
As you know, the agency has devoted considerable effort to improve rear braking signals, culminating in its proposal that passenger cars be equipped with a single high-mounted stop lamp on the centerline of the vehicle. The concept of a pre-brake application signal is a familiar one to us, but the agency has conducted no formal research with respect to it, and in view of its stop-lamp proposal, is unlikely to do so. The technical issues that we consider relevant to your concept are (1) whether most rear-end accidents are preceded by a "panic" stop by the struck vehicle, (2) whether panic stops involve unique driver behavior that can be reliably discriminated from non-panic stop behaviour and used to trigger a pre-braking signal, and (3) whether the resulting signal will automatically result in a decrease in the reaction time of following drivers that is equal to the early warning time it provides. We know of no scientifically acceptable data that support these critical assumptions. We are especially concerned that a high rate of "false alarms" may lead to a decrease in the overall warning value of the stop lamp signal itself, i.e., the "cry wolf" phenomenon. This could lead to a significant reduction in the effectiveness of any proposed system.
Paragraph 2.1 of SAE Standard J586d, Stop Lamps, September 1977, incorporated by reference in Standard No. 108, defines a stop lamp as one whose operation indicates "the intention of the operator of a vehicle to stop or diminish speed by braking."
Your device would activate the stop lamp under a condition indicating an intent other than the above, which could impair the effectiveness of the stop lamps. We view any use of required lighting equipment for a purpose other than as defined, as an "impairment" within the prohibition of paragraph S4.1.3 of Standard No. 108 if the device is installed as original equipment. If the device is sold in the after-market, our laws preclude modifications that "render ineffective in whole or in part" required lighting equipment, if the modifications are performed by a person other than the vehicle owner. We would consider your system prohibited by this provision as well.
Noting your comment that the device may be used for testing on school buses, this means that there is no prohibition under the laws that we administer which would forbid a school district from installing your device on its fleet. Such a modification would be subject to laws of the jurisdiction in which the school bus is registered and operates.
SINCERELY,
September 22, 1981
To: Frank Berndt Chief Counsel NHTS Administrator
Subject: Installation of Automatic Safety Alert Device on Motor Vehicles
I currently have an alert device which automatically turns on the stop lights of the vehicle when the accelerator is released. This installation is simple, inexpensive and easy to install. I am requesting your consideration and permission for installing this device for experimentation and testing on school busses and other motor vehicles.
I am also requesting interpretation of 49 CFR 571, S108 to determine if this device meets the requirements for installation on motor vehicles under this provision.
On September 15, 1981, a vehicle (1981 Citation), with this alert device installed, was inspected by Dr. Carl Clark and his associates and all pertinent data is on file in his office.
If further testing or inspection of this car is required, I would return to Washington at any time. I would also consider allowing the use of this car for a period of testing by your office or will furnish any additional information required.
If interpretation of 49 CFR 571, S108 is not favorable, or if this alert device is not considered under this provision, I will petition for modification of the rules to allow use of this device on motor vehicles on an individual basis, in accordance with Part 552.
Your early consideration of this matter will be greatly appreciated.
Kenneth G. Moyer
PETITION
To: Administrator National Highway Traffic Safety Administration 400 SEVENTH STREET WASHINGTON, D.C. 20590
I, Kenneth G. Moyer, of 6400 Goldbranch Road, Columbia, S. C. 29206, petition for a change in rulemaking standards to allow this Automatic Safety Alert Device to be installed on motor vehicles, on an individual basis, in accordance with 49 CFR 571,S108.
Claim: An early-warning electrical system for vehicles of the type characterized by a normally open warning switch, mechanically co-operating with the accelerator pedal and throttle linkage and electrically connected to the vehicle rear light circuit to automatically light the brake lights when the pressure on the accelerator pedal is removed. The brake lights which are lit by applying pressure to the brake pedl are red in color and are universally recognized as indication that the vehicle is about to slow or stop. This alert device allows the brake light system to be activated when there is no pressure on the accelerator pedal.
The primary object of this device is to provide a simple and inexpensive warning system to be installed on vehicles without making changes to the linkage system and is designed to operate separately of the brake pedal switch.
This warning system alerts following drivers that the vehicles speed is decreasing and, therefore, provides time for the following driver to avoid a dangerous condition.
This alert device has been approved for use in the state of South Carolina. My contact is Maj. Lanier, phone-803-758-3315, of the South Carolina Highway Department.
I am to meet with the Highway Transportation Department in ten days to discuss installing this device on South Carolina school busses. My contact is Ralph Hendricks, phone-803-758-2762.
One U. S. car manufacturer and one foreign firm have requested information on this alert device for possible installation on new cars.
In view of the enclosed information, I request this petition be considered for a change in rulemaking standards, in accordance with 49 CFR 571,S108.
With this alert device installed on motor vehicles, it could possibly decrease the excessively high rate of rear-end collisions.
No alert devices are installed on any vehicles except those I personally own.
This alert device does not affect the normal operation of the brake pedal to operate the stop lights when the brake pedal is applied.
I am awaiting the results of consideration by the National Highway Safety Administration.