Interpretation ID: 2345y
12249 S. 1565 E.
Draper, UT 84020
Dear Mr. Smith:
This is in reply to your letter of January 26, l990, to the agency with respect to a safety lighting device. You have asked for our recommendations regarding this invention.
The problem addressed by your invention is "that vehicles need some way of signaling following drivers if the headlamps of their vehicles are blinding you." Your solution is to install a button that activates the backup lamps and extinguishes them in a matter of a second or less. One alternative would be to operate only a single backup lamp, and another, to activate only the license plate lamp. This would provide a warning to the following driver.
The agency is concerned with glare, but its investigation of the phenomenon indicates that there are two types: discomfort glare, and disabling glare. Although it is certainly an annoyance, the glare produced by a headlamp shining into a rear view mirror is discomfort glare. In our judgment, a vehicle driver looking into the mirror will not suffer disabling glare so that he is unable to discern vehicles approaching, or pedestrians in the roadway; most vehicles are equipped with manual "day/night" mirrors which may be easily operated in the event of discomfort. Equipment manufacturers have already addressed the problem by providing rear-view mirrors that have a photoelectric cell that dips them when a certain level of light intensity is reached. In summary, the agency does not believe that there is a nationwide safety problem requiring it to mandate the use of your device on motor vehicles as new vehicle equipment.
As an aftermarket item which a dealer could offer a new-car purchaser, its installation would be subject to the general prohibition in Federal Motor Vehicle Safety Standard No. l08 that supplemental lighting devices shall not impair the effectiveness of the lighting equipment that Standard No. l08 requires. The question to be answered, therefore, is whether the device would impair the effectiveness of the backup lamps, or other rear lighting devices. The problem here is the necessity of rear lighting devices to provide clear and unambiguous signals and messages to following drivers. Anytime a lighting device does not provide a cue to which a following driver is accustomed, the potential for confusion arises. The driving public is unfamiliar with the sudden, though temporary, activation of the backup lamp, at normal driving speeds, or a modification in intensity of the license plate lamp. Without a substantial nationwide public education campaign, the signal imparted by your device is not likely to be understood by a following driver, and might distract him from the signals of the other rear lighting devices. In this sense, we believe that your device might impair the effectiveness of the lighting equipment that Standard No. l08 does allow.
You have also noted the State prohibitions against use of backup lamps when the car is going in a forward direction. Even if the agency concluded that the device was permissible and would not cause impairment, the States are not precluded from enacting and enforcing their own standards on the use of lighting systems.
You may be interested to know that two letters to the Editor of The New York Times have appeared on this issue in the last month which suggest the use of existing lighting equipment to signal following drivers that their upper beams are on. I enclose these letters for your consideration.
I am sorry that we cannot be more encouraging in our remarks, but we do appreciate your interest in motor vehicle safety.
Sincerely yours,
Stephen P. Wood Acting Chief Counsel
Enclosure
/ref: 108 d:3/22/90