Interpretation ID: nht76-2.31
DATE: 03/05/76
FROM: AUTHOR UNAVAILABLE; S. P. Wood; NHTSA
TO: Department of California Highway Patrol
TITLE: FMVSS INTERPRETATION
TEXT: This is in reply to your letter of March 10, 1976, asking whether S4.6(b) of Motor Vehicle Safety Standard No. 108 allows a flashing side marker lamp "in any location on the side of a motor vehicle without having to comply with State law pertaining to side-mounted turn signals."
S4.6(b) allows side marker lamps to flash for signalling purposes. Since a flashing side marker lamp is in essence a side turn signal lamp, any State regulation specifically addressed to location and flash rate of side turn signals would appear to be preempted by Standard No. 108, if the side marker lamp is combined with a side turn signal lamp. If the side turn signal lamp is a separate lamp, then it would be subject to State regulation.
Your inquirer wishes to install "a side marker lamp on each side near the middle of the trailer to flash with the turn signal lamps." If the lamp to be added is not the intermediate side marker lamp required by Standard No. 108 for trailers whose length is 30 feet or more, it would be governed by the California Vehicle Code and not preempted.
We intend to address the issues of side mounted turn signal lamps, flashing side marker lamps, and flashing headlamps in a rulemaking proposal whose publication is imminent, and I will include your letter in the Docket as a comment to be considered.
YOURS TRULY,
DEPARTMENT OF CALIFORNIA HIGHWAY PATROL
March 10, 1976
File No.: 61.A218.A4343
James C. Schultz Chief Counsel National Highway Traffic Safety Administration
We have a question concerning an interpretation of Section S4.6(b) of FMVSS No. 108. This paragraph states that "means may be provided to flash headlamps and sidemarker lamps for signaling purposes".
We have had an inquiry from a supplier to a major trailer manufacturer as to whether or not he can install a sidemarker lamp on each side near the middle of the trailer to flash with the turn signal lamps. The California Vehicle Code provides that "side-mounted turn signal lamps of an approved type projecting a flashing amber light to either side may be used to supplement the front and rear turn signals. Side-mounted turn signal lamps mounted to the rear of the center of the vehicle may project a flashing red light no part of which shall be visible from the front." The Administrative Regulations require the approved side turn signal lamps to meet the same requirements as SAE Standard J914a.
These standards were adopted to assure that lamps installed on a vehicle as a side turn signal lamp had sufficient performance to be of value to other motorists both day and night, whether mounted on a passenger car, a truck or a trailer. A range of mounting heights was established in our regulations so that the side turn signal lamp would be near the eye height of drivers alongside the vehicle.
In the past, the only vehicles flashing the sidemarker lights as allowed by your standard were passenger cars. In these cases, we had read your standard as permitting the minimum number of sidemarker lamps required by your standard to flash but not giving authority for the indiscriminate addition of numerous other sidemarker lamps in other locations on the side of the vehicle.
We do not see any particular problem with allowing a required sidemarker lamp to flash simultaneously with a required turn signal lamp on the same side and on the same end of the vehicle. Unfortunately, one major passenger car manufacturer selected a system that caused the sidemarker lamps to flash alternately with the turn signals which, in our opinion, detracts from the signal value of the required turn signal instead of adding to it, particularily when both signals are seen to flash alternately at certain angles from the front or rear of the vehicle.
We now come to the question. Does Section S4.6(b) permit a manufacturer to install and flash with the turn signal any sidemarker lamp in any location on the side of a motor vehicle or trailer without having to comply with State law pertaining to side-mounted turn signals?
If the answer is "yes", we ask that you consider an appropriate revision to FMVSS No. 108 within the near future. We suggest that an amendment be proposed to require the side turn signals to flash simultaneously and in unison with the appropriate turn signal rather than alternately with the signal. In addition, we request that:
1. Only the minimum required sidemarker lamps on the each end of the vehicle be allowed to flash with the turn signal lamps.
2. Only sidemarker lamps near the eye height of passenger car drivers alongside the vehicle be allowed to flash. Sidemarker lamps at the extreme tops of trucks and trailer lamps are so far removed from the turn signal that another driver seeing them blink would likely be distracted by them instead of relating them to a turn being signaled.
3. New provisions be worded so attempts of various state laws to require higher-performing side mounted turn signals that are effective in the daytime are not placed in limbo because the Federal Standard allows a far less effective lamp of only 0.25 to 0.62 candlepower to flash in its place.
4. High mounted sidemarker lamps on buses not be allowed to flash as part of the turn signal system, because transit buses are permitted in this State to simultaneously flash all clearance and sidemarker lamps as a crime warning signal when driver or passengers are accosted. These signals are visible both from police patrol cars and police helicopters. Before-and-after surveys have shown that they are quite effective in making substantial increases in the rate of apprehension of suspects.
5. Headlamps not be allowed to flash with the turn signal lamps as now permitted. It is more important that a driver of a vehicle be able to see a lighted roadway in the direction in which he is going rather than using the headlamps to supplement an already effective front turn signal.
We would appreciate receiving your interpretation of the flashing headlamp and sidemarker lamp provisions. If you wish, we will be pleased to send you copies of our regulations on side turn signal lamps, alternately flashing headlamps for emergency vehicles, and data on the reduction in crime on buses following the installation of flashing crime warning lamps.
WARREN M. HEATH Commander Engineering Section