Interpretation ID: nht76-2.41

DATE: 10/29/76

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Department of California Highway Patrol

TITLE: FMVSS INTERPRETATION

TEXT: This is a reply to your letter of September 16, 1976, referencing an opinion letter to you dated October 21, 1969, and asking whether it conflicts with an opinion letter to Ford Motor Company dated "December 5, 1975". (The true date of the letter is July 7, 1975, we do not know why your copy is dated otherwise).

The 1969 letter informed you that "if one compartment or lamp [in a multicompartment lamp] meets the photometric requirements [of Standard No. 108] the additional compartments or lamps are considered as additional lamps and are, therefore not regulated by . . . Standard No. 108 except by S3.1.2.". The letter also stated that "lamps on a vehicle and not required by this standard are generally subject to regulation by the States." Our 1975 letter to Ford, on the other hand advised the company in effect that the performance of the entire multicompartment assembly was covered by Standard No. 108, and that section 25950(b), of the California Vehicle Code was preempted by it. You have asked whether our letter to Ford conflicts with our earlier letter to you.

There is no present conflict. In an amendment to Standard No. 108 effective January 1, 1973, (copy enclosed) the agency adopted paragraph S4.1.1.12 and figure 1 which established minimum photometric requirements that must be met by multicompartment tail, stop, and turn signal lamps. The act of establishing requirements for the additional compartments in a multicompartment lamp thus voided the 1969 letter to you and the interpretation to Ford is the correct one.

The Monarch taillamp, therefore, must meet the requirements of Table 1 of standard No. 108 and is not a lamp that is "in addition to the minimum required number" as that term is used in California Vehicle Code section 25950(b), which appears to have been amended in an effort to include it.

We appreciate your suggestion on an amendment to Standard No. 108 on lens color.

SINCERELY,

DEPARTMENT OF CALIFORNIA HIGHWAY PATROL

September 16, 1976

File No.: 61.A218.A3107

Frank Berndt Acting Chief Counsel National Highway Traffic Safety Administration

We recently received a copy of Mr. James C. Schultz's opinion of December 3, 1975, to Ford Motor Company regarding the color of unlighted taillamps. This interpretation appears to conflict with the enclosed interpretation of October 21, 1969, we requested from NHTSA on a similar subject.

In answer to a question we raised on multicompartment lamps, Dr. Robert Brenner informed us that, "if one compartment or lamp meets the photometric requirements, the additional compartments or lamps are considered as additional lamps and are, therefore, not regulated by Motor Vehicle Safety Standard No. 108 except by S3.1.2". He also stated that "lamps on a vehicle, and not required by this standard, are generally subject to regulation by the states". These statements appear to mean that once a manufacturer meets the minimum requirements for taillamps for FMVSS No. 108, any additional lamps he chooses to add do not fall under that standard. With respect to the unlighted color of the minimum required lamps, we agree that we are preempted. However, in the case of the Ford lamp, the taillamp section in question was an additional one to which Ford, as an afterthought, attached an amber filter. This lamp was not needed to comply with the federal standards for taillamps, and was an additional lamp not governed by the federal standards as stated in the October 21, 1969, NHTSA interpretation. We, therefore, request that you reconsider whether the interpretation in your letter to Ford Motor Company was overly broad.

The color requirements of the Vehicle Code were amended last year and Section 25950(b) referred to in Ford Motor Company's letter now reads as follows:

"All lamps and reflectors visible from the rear of a vehicle shall be red, except that stop lamps, turn signal lamps and front side-marker lamps required by Section 25100 may show amber to the rear."

"This section applies to the color of a lamp whether lighted or unlighted, and to any reflector exhibiting or reflecting perceptible light of 0.05 candlepower or more per foot-candle of incident illumination, except that taillamps, stop lamps, and turn signal lamps that are visible to the rear may be white when unlighted () and, with respect to vehicles manufactured after January 1, 1974, only such lamps that are in addition to the minimum required number and are visible to the rear may be white or amber when unlighted."

Until 1961, the Vehicle Code color requirements applied to all lamps, whether lighted or unlighted. In that year, the Legislature amended the Code to permit rear lamps to be white when unlighted in view of the General Motors and Chrysler taillamps which, for styling purposes, had white lenses to blend in with the chrome trim on the rear fenders and bumpers. At that time, the visibility problem with the white lenses was not initially apparent. It was then found that, in at least one design, the white lens reflected so much sunlight during the daytime that it washed out much of the effectiveness of the red stoplamp and turn signal. The white lenses were not objectionable on lamps that supplemented the regular red lensed rear lamps, but they were not satisfactory as a total replacement for those lamps.

Even though we recognize NHTSA's preemption in allowing a manufacturer to use any unlighted lens color he wishes for the minimum required rear lamps, we have a strong objection to that position. Observations of stoplamps in the daytime have shown that those with white lenses are less effective in attracting another person's attention than a lamp of the same output with a red lens. It might be argued that this problem of reduced signal effectiveness does not apply to taillamps, since they are only lighted at nighttime. However, during high brightness day-time fog when lights were required on vehicles, the red taillamps are so dim that the white or amber lens covers become a safety hazard due to the high brightness masking of the red light.

We have no technical objection to a rear lamp lens being any color darker than red, because this would improve the contrast of the red signal against its background. We are highly concerned about the use of lenses that are lighter than the required red because of their effect in washing out the signal in daylight. Standard No. 108 already acknowledges this difference with respect to turn signals where amber is required to have more candlepower output than red for equivalent daytime effectiveness. You might wish to make observations yourself in comparing the daylight effectiveness of the red lens on the Monarch with that of the amber lens when the taillamps are turned on. Daytime observations of the white lens on the various Cadillac year models illustrate varying degrees of effectiveness depending upon the slant of the lens and the taillamp intensity.

We would appreciate hearing from you with respect to a clarification of the two interpretations. We also ask that NHTSA consider amending Standard No. 108 to prohibit taillamps and stoplamps from having a lens cover of white, amber, or any other color that has a lighter contrast with the signal than the red lens.

WARREN M. HEATH Commander Engineering Section