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NHTSA Interpretation File Search

Overview

NHTSA's Chief Counsel interprets the statutes that the agency administers and the standards and regulations that it issues. Members of the public may submit requests for interpretation, and the Chief Counsel will respond with a letter of interpretation. These interpretation letters look at the particular facts presented in the question and explain the agency’s opinion on how the law applies given those facts. These letters of interpretation are guidance documents. They do not have the force and effect of law and are not meant to bind the public in any way. They are intended only to provide information to the public regarding existing requirements under the law or agency policies. 

Understanding NHTSA’s Online Interpretation Files

NHTSA makes its letters of interpretation available to the public on this webpage. 

An interpretation letter represents the opinion of the Chief Counsel based on the facts of individual cases at the time the letter was written. While these letters may be helpful in determining how the agency might answer a question that another person has if that question is similar to a previously considered question, do not assume that a prior interpretation will necessarily apply to your situation.

  • Your facts may be sufficiently different from those presented in prior interpretations, such that the agency's answer to you might be different from the answer in the prior interpretation letter;
  • Your situation may be completely new to the agency and not addressed in an existing interpretation letter;
  • The agency's safety standards or regulations may have changed since the prior interpretation letter was written so that the agency's prior interpretation no longer applies; or
  • Some combination of the above, or other, factors.

Searching NHTSA’s Online Interpretation Files

Before beginning a search, it’s important to understand how this online search works. Below we provide some examples of searches you can run. In some cases, the search results may include words similar to what you searched because it utilizes a fuzzy search algorithm.

Single word search

 Example: car
 Result: Any document containing that word.

Multiple word search

 Example: car seat requirements
 Result: Any document containing any of these words.

Connector word search

 Example: car AND seat AND requirements
 Result: Any document containing all of these words.

 Note: Search operators such as AND or OR must be in all capital letters.

Phrase in double quotes

 Example: "headlamp function"
 Result: Any document with that phrase.

Conjunctive search

Example: functionally AND minima
Result: Any document with both of those words.

Wildcard

Example: headl*
Result: Any document with a word beginning with those letters (e.g., headlamp, headlight, headlamps).

Example: no*compl*
Result: Any document beginning with the letters “no” followed by the letters “compl” (e.g., noncompliance, non-complying).

Not

Example: headlamp NOT crash
Result: Any document containing the word “headlamp” and not the word “crash.”

Complex searches

You can combine search operators to write more targeted searches.

Note: The database does not currently support phrase searches with wildcards (e.g., “make* inoperative”). 

Example: Headl* AND (supplement* OR auxiliary OR impair*)
Result: Any document containing words that are variants of “headlamp” (headlamp, headlights, etc.) and also containing a variant of “supplement” (supplement, supplemental, etc.) or “impair” (impair, impairment, etc.) or the word “auxiliary.”

Search Tool

NHTSA's Interpretation Files Search



Displaying 13941 - 13950 of 16514
Interpretations Date
 search results table

ID: nht93-8.14

Open

DATE: November 16, 1993

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Ray Paradis -- Manufacturing Manager, Dakota Mfg. Co., Inc.

TITLE: None

ATTACHMT: Attached to letter dated 8/31/93 from Ray Paradis to Pat Boyd (OCC-9151)

TEXT:

This responds to your letter of August 31, 1993, to Pat Boyd of this agency with respect to the trailer conspicuity requirements of Federal Motor Vehicle Safety Standard No. 108. You have enclosed literature and photos of several of your trailers, and ask for our comments in several areas.

Your first remark is "Deck heights are from 22" to 39 1/2"." We understand this to ask whether these are acceptable heights for mounting conspicuity treatments. Standard No. 108 was amended on October 6, 1993, to specify a mounting range as close to 375 to 1525 mm as practicable, i.e. approximately 15 to 60 inches. Your "deck heights" are within this range.

Your second remark is "(t)he rear design does not allow for continuous tape all models." Standard No. 108 requires a horizontal strip of retroreflective sheeting across the full width of the trailer. Paragraph S5.7.1.3(b) anticipates that the length of the color segments may have to be modified to facilitate using material near rear lamps. In the worst cases of trailers with rear surfaces no wider than the minimum required for lamps, breaks in the rear treatment are unavoidable to clear the lamps. But NHTSA expects the manufacturer to minimize the breaks by using red material adjacent to red lamps.

Your third remark is (t)he side extension model has fold-up sides #2." We understand this to ask whether striping must be applied so as to be visible only when the extension is folded, or whether striping must also be visible when the extension is in use, i.e., whether striping must be applied to both surfaces of the extension so that it is visible regardless of the position of the extension. Although Standard No. 108 does not directly address this question, we believe that motor vehicle safety requires visibility of conspicuity treatment at all times. The standard does require that striping not be obscured by other motor vehicle equipment or trailer cargo, reflecting the agency's intent that striping be visible when the trailer is performing its intended work-related functions. This means that side extension model trailers should be equipped with conspicuity treatment that is visible both when the extensions are folded and unfolded.

Your final remark is "((d)oes the front require any stripe." Under the assumption that you refer to the front side of a trailer and not the front that is hidden behind the towing vehicle, the answer is yes. Standard No. 108, in pertinent part, requires conspicuity treatment to be applied as close to the front of a trailer as practicable. Goosenecks and tongues are part of the trailer front and are portions of a trailer requiring conspicuity treatment if practicable.

I hope that this answers your questions.

ID: nht93-8.15

Open

DATE: November 16, 1993

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Larry Grabsky -- VML and Colonna Corp.

TITLE: None

ATTACHMT: Attached to letter dated 10/01/93 Est. from Larry Grabsky to John Wilman

TEXT:

This is reply to your recent letter asking our views on the use of decorative neon lamps, or of oscillating or revolving ones.

This agency establishes the Federal motor vehicle safety standards which must be met from the time a motor vehicle is manufactured up until its sale to its first purchaser for purposes other than resale. The new car dealer is responsible for ensuring that any lighting equipment that it adds before the sale of the vehicle does not impair the effectiveness of lighting equipment that is required by the standard. The determination of whether an impairment exists is made by the person responsible for adding the equipment. If this determination appears clearly erroneous, NHTSA will question it. In addition, all lighting equipment added before the vehicle's first sale must be steady burning when it is used.

If the lighting equipment is added after the vehicle's sale by a manufacturer, dealer, distributor, or motor vehicle repair business, it is subject to the restriction that it not "render inoperative, in whole or in part" any lamp that has been installed in accordance with Standard No. 108.

Supplementary motor vehicle lighting equipment, whether added before or after initial sale of the vehicle, is subject to the laws of States in which the vehicle is operated, even if the equipment is not prohibited under Federal law.

With respect to neon lights, we are aware of aftermarket installations on the underside of vehicles that illuminate the pavement below. If such lamps create glare that distracts another motorist from perceiving, for example, the turn signals in use we would consider that an impairment and a partially rendering inoperative within the meaning of those terms. We are unable to advise you on State laws regarding the use of neon lights on vehicles, and suggest that you write for an opinion to the American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203.

We are unsure what you mean by "oscillating" but Standard No. 108, in general, requires lamps added before a vehicle's initial sale to be steady burning in use, unless otherwise permitted (such as turn signals and hazard warning signals, and automatic flashing of headlamps for signalling purposes). Installation of a non steady burning lamp by a manufacturer, dealer, distributor, or motor vehicle repair business after initial sale could be viewed as a rendering inoperative depending upon the circumstances. Standard No. 108 does allow a motorcycle to be equipped with a modulating headlamp for daytime use. The modulation permitted is 240 +/- 40 cycles per minute. When NHTSA proposed to allow the modulating headlamp, some commenters were concerned that the flashing might trigger a photic reaction

akin to an attack of epilepsy, in onlookers. We believe that the reaction is most likely to occur at a frequency of 10 hz against a very dark background. Thus, care should be taken in the use of supplementary lamps that are not steady burning.

As for revolving lamps, we believe that these are generally found on police and emergency vehicles such as ambulances and tow trucks. Whether it is permissible to equip a vehicle with these lamps and to use them is a question to be answered under State law.

ID: nht93-8.16

Open

DATE: November 16, 1993

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Dennis G. Moore -- President, Sierra Products Inc.

TITLE: None

ATTACHMT: Attached to letter dated 9/29/93 from Dennis G. Moore to John Womack

TEXT:

We have received Your letter of September 29, 1993, with reference to the location requirements of Standard No. 108 for identification (i.d.) lamps.

Table II of the standard in pertinent part specifies the following location for i.d. lamps: "On the rear - 3 lamps as close as practicable to the top of the vehicle at the same height, as close as practicable to the vertical centerline...." You reference at least two instances in the past 20 years or longer in which "NHTSA has allowed the slight misalignment of I.D. lights because of 'Practical' circumstances," and have asked for copies of these interpretations.

We are unaware of these interpretations. In their absence, you have asked for an interpretation of the phrase "at the same height" that would permit the mounting height of the center lamp to deviate slightly from the height of the two lamps that flank it, as shown in your letter. You depict two other possible configurations in which the three lamps are mounted at identical heights. In one configuration, the lower edges of the outboard lamps hang below the frame "making them vulnerable to being damaged or knocked off" in your opinion. In the second configuration, the lamps are raised and protected, but the center lamp is somewhat obscured by the "typical roller or protective pad." You deem these configurations undesirable for safety reasons.

The question to be answered is whether the configuration you prefer is "as close as practicable to the top of the vehicle at the same height" (note the absence of a comma between "vehicle" and "at"). The determination of practicability is initially that of the manufacturer. Unless it is clearly erroneous, NHTSA will not question it. In the absence of a superstructure, the frame location may be regarded as being "as close as practicable to the top of the vehicle..." Because "at the same height" is part of the same phrase, practicability also governs placement of the lamps at the same height. A manufacturer may determine that, for the sake of practicability, i.d. lamps may be mounted at a height sufficient to protect them from breakage (the outboard lamps) and to ensure compliance with photometric requirements (the center lamp). The configuration you depict is sufficiently close to the literal reading of the phrase "at the same height" that NHTSA would not question the manufacturer's determination of practicability with respect to the mounting height of the center i.d. lamp.

ID: nht93-8.17

Open

DATE: November 16, 1993

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: James E. Walker -- Manager, LSI Laboratories, Lighting Sciences, Inc.

TITLE: None

ATTACHMT: Attached to letter dated 10/4/93 from James E. Walker to John Womack

TEXT:

We are replying to your letter of October 4, 1993, with respect to the requirements of Federal Motor Vehicle Safety Standard No. 108 for taillamps.

You believe that a discrepancy exists because paragraph S5.1.1 "requires equipment to be designed to Tables I, II (you mean III), and S7, which references SAE J585e for the Tail lamp," whereas paragraph S5.1.1.11 "requires Table 1 of this specification to be substituted for the values achieved by Figures 1a and 1b, and in addition, to substitute Table 1 of SAE J585e by the values achieved by multiplying the percentages of Figure 1a by Table 1 and 3 of SAE J588 NOV84 Turn Signal Lamps."

You assume that the photometric requirements are those of Figure 1a, 1b, and 1c. Your assumption is correct. However, there is no discrepancy in the standard. The requirements for motor vehicle lighting equipment are set forth in section S5. Paragraph S5.1.1 requires lighting equipment to comply with the SAE materials contained in the tables, except as may be provided in succeeding paragraphs of Paragraph S5.1.1. Tables I and III incorporate by reference SAE Standard J585e, Tail Lamps, September 1977. However, on March 3, 1993, NHTSA redesignated Paragraph S5.1.1.11 (with references to Figures 1a and 1b) as S5.1.1.6, and revised it to include, among other things, the reference in paragraph S5.1.1.12 to Figure 1c. The same notice removed paragraph S5.1.1.12 from the standard. New Paragraph S5.1.1.6 states that instead of the photometric values specified in Table 1 of SAE J585e, taillamps shall comply with those of Figures 1a, 1b, and 1c.

I enclose a copy of the amendment for your information, and hope that this answers your question.

ID: nht93-8.18

Open

DATE: November 16, 1993

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Dennis G. Moore -- President, Sierra Products, Inc.

TITLE: None

ATTACHMT: Attached to letter dated 8/12/93 from Dennis G. Moore to John Womack (OCC-8992)

TEXT:

We have received your letter of August 12, 1993, "requesting a legal clarification detailing where FMVSS 108 requires a Clearance Light to be mounted." It is clear from your letter that it is the lateral spacing of clearance lamps that concerns you as you believe that it is not uncommon to see them mounted as much as 6 to 8 inches "'inside' the side extremities of huge vehicles."

With respect to lateral spacing, Table II of Standard No. 108 requires clearance lamps to be mounted "to indicate the overall width of the vehicle...." The standard does not require the lamps to be mounted at the widest point of the vehicle, nor does it require them to be mounted as far apart as practicable. We believe that manufacturers generally try to mount clearance lamps to "indicate" the overall width of the vehicle, but we recognize that there may be certain circumstances and/or configurations that require mounting of the lamps at something less than the widest point.

ID: nht93-8.19

Open

DATE: November 16, 1993

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Michinori Hachiya -- Director and General Manager, Nissan Research and Development, Inc.

TITLE: None

ATTACHMT: Attached to letter dated 10/12/93 from Michinori Hachiya to John Womack (OCC-9190)

TEXT:

This responds to your letter of October 12, 1993, asking several questions concerning the labeling requirements of the recent final rule mandating the installation of air bags in passenger cars and light trucks (58 FR 46551, September 2, 1993). Your questions concern the labeling requirements in this final rule.

As you may know, NHTSA has received two petitions for reconsideration of the September 2 final rule. The petitions raise issues concerning the labeling requirements. We will address your first, second, and fourth questions in the notice responding to the petitions for reconsideration.

Your other questions and the response to each follow.

The mandatory air bag rule establishes type size and format requirements for the air bag maintenance label (section 4.5.1(a)), but no similar requirements for the air bag warning label in section 4.5.1(b). Are we correct in understanding that the lettering of the warning label may be of any size or format, so long as the letters are legible? May different type size and formats be used if the two labels are combined?

You are correct that there are not any size requirements for the air bag warning label. Therefore, so long as the information on the label is legible, the lettering may be of any size. It is unclear what you mean by format, but the warning label must contain the exact words, in the exact order, as specified in section 4.5.1(b). The issue of combining warning and maintenance labels will be addressed in the notice responding to the petitions for reconsideration.

It is our understanding that warning labels that do not refer to air bags or seat belts may continue to be placed on the side of the sun visor opposite from the air bag warning label. Nissan currently places a label on the sun visor of a convertible model which provides instructions regarding the use of the convertible top. May this type of label continue to be placed on the sun visor, so long as it is on the side of the visor opposite from the air bag warning label?

Section S4.5.1(b)(2) specifies (1) that no other information shall be on the same side of the sun visor as the air bag warning label, and (2) that no other information concerning air bags or seat belts shall appear anywhere on the sun visor. Therefore, you are correct that information concerning the operation of a convertible top could be placed on the side of the sun visor opposite the side with the air bag warning label.

I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992.

ID: nht93-8.2

Open

DATE: November 8, 1993

FROM: Andrew Tweddle -- AV Technology Corporation

TO: Walter K. Myers -- Attorney-Advisor, Office of the Chief Counsel, NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 3/17/94 from John Womack to Andrew Tweddle (A42; Part 571.7(c))

TEXT:

AV Technology is in the process of responding to a Department of the Army draft specification for an armored security vehicle. AV Technology will be proposing its combat vehicle, the Dragoon ASV. Our fully armored vehicle will be equipped with the AV Technology manufactured UGWS weapons station, which carries a 40mm grenade launching machine gun, a .50 caliber machine gun, as well as a matched bank of smoke grenade launchers. The Dragoon is capable of being fitted with weapons as heavy as a 105mm anti-tank gun. The dragoon has the capability to defeat Main Battle Tanks, with more agility, and speed than many MBTs in service today. Based on the capabilities of the Dragoon ASV combat vehicle we would like to request that the National Highway Traffic Safety Administration consider it for exclusion from federal motor vehicle safety standard and requirements.

The Dragoon is constructed of high hardness armor, and includes a permanently mounted weapons station. In addition to its armor and weapons capabilities, the Dragoon features a powerpack system, a configuration usually found only on main battle tanks. Because of these features, as well as the army's own definition of this vehicle as a combat vehicle rather than a tactical vehicle, (ref: Tacom Specification, Sept. 20, 1993 Pg. 12, 21), we feel there are sufficient grounds for exemption.

In a letter addressed to Verne Corporation, a division of AV Technology, dated August 7, 1989 your office stated, "If the vehicle is a motor vehicle that has been manufactured for and sold directly to the armed forces in conformity with contractual specifications, it is not required to conform to the Federal motor vehicle safety standards." In reference to past vehicles sold to the U.S. Armed Forces, the letter states, "This means that the ASVs sold to the armed forces have not been required to conform to the federal standards." Because of the limited number of the Dragoon ASVs to be manufactured for this contract, its role as a combat vehicle, and past precedent set by Verne Corporation, AV Technology expects compliance with MIL-STD-1180, which mirrors the federal motor vehicle specifications in many respects, is adequate to meet the need for on road safety.

If you require any additional information or details on our combat vehicle please don't hesitate to contact us. Thank you for considering the Dragoon armored combat vehicle for exclusion from federal safety standards and regulations, we look forward to hearing from you soon.

ATTACHMENT Dragoon Armored Security Vehicles (ASV) brochure. (Text omitted.)

ID: nht93-8.20

Open

DATE: November 16, 1993

FROM: Jim Davis -- President, Russell Performance Products

TO: David Elias -- DOT

COPYEE: Bill Collins -- Titeflex

TITLE: None

ATTACHMT: Attached to letter dated 5/12/94 from John Womack to Jim Davis (A42; Std. 106), letter dated 10/22/93 from Jim Davis to David Elias (OCC-9249), and letter dated 10/22/93 from Jim Davis to NHTSA Office of Vehicle Safety Standards, Crash Avoidance Division

TEXT:

After our recent phone conversation I re-read my copy of NHTSA's 49 CFR Ch. V (10-1-88 Edition) covering the marking of brake hose assemblies. Unless I am reading this incorrectly, it seems that we do not need marking on the hose once it has been made into an assembly.

S5.2.2 says that "Each hydraulic brake hose shell be labelled or cut from bulk brake hose that is labelled, etc." But then it goes on to say that "The formation need not be present on hose once it has become part of a brake hose assembly or after it is installed in a motor vehicle." It would seem to me that the phrase "once it has become a part of a brake hose assembly" would relieve us of the necessity to mark the hose.

The copy that I am reading this from is a very indistinct Xerox that I may be misinterpreting.

I can understand the need for interim marking if the hose is placed in commerce in an unassembled state. But that is not the case here where we are the ONLY customer with Titeflex for this particular hose and we make it into assemblies which otherwise meet all the specifications required by NHTSA.

I will call you in a few days to discuss this with you.

ID: nht93-8.21

Open

DATE: November 17, 1993

FROM: David Shapiro -- RV Designer Collection, Woodbridge, Inc.

TO: Chief Counsel -- NHTSA

TITLE: Motor Vehicle Safety Standard No. 302

ATTACHMT: Attached to letter dated 2/10/94 from John Womack to David Shapiro (A42; Std. 302)

TEXT:

We are in the process of preparing a line of decorative products for sale in the recreational vehicle aftermarket.

Products will include drapes and other fabric window coverings, and bedspreads and other fabric bedding.

The products will be designed for use in motorhomes, travel trailers and similar multipurpose passenger vehicles.

All of these products will be sold in the recreational vehicle aftermarket, to consumers who already own recreational vehicles.

We have been told by your department that motor vehicle safety standard 302 does not apply to aftermarket products. We would appreciate receiving a letter from you confirming this.

ID: nht93-8.22

Open

DATE: November 18, 1993

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Jason Backs -- Engineering Department, Travis Body and Trailer, Inc.

TITLE: None

ATTACHMT: Attached to letter dated 10/19/93 from Jason Backs to Taylor Vinson

TEXT:

We have received your FAX of October 19, 1993, to Taylor Vinson of this Office, asking for an interpretation of the trailer conspicuity requirements of Federal Motor Vehicle Safety Standard No. 108 as it applies to a dump trailer manufactured by your company.

With respect to the location of the horizontal side conspicuity treatment, you prefer not to place it on the rubrail because "our present extrusions have raised ridges on the outer surface." You propose to apply the conspicuity treatment between each side stake, resulting in 58% coverage of the trailer side. The tape is "in full view" from a point perpendicular to the side of the trailer, but at approximately 30 degrees from perpendicular, the edge of the tape begins to be obstructed by the side stake. You ask for our concurrence that your proposed treatment is in accordance with Standard No. 108.

We are pleased to provide our concurrence. The mounting height requirements of Paragraph S5.7.1.4.2 are specified in terms of practicability. The rule was amended on October 6, 1993, to specify a mounting height of "as close as practicable to not less than 375 mm and not more than 1525 mm above the road surface." The determination of practicability, in the first instance is that of the manufacturer certifying compliance with Standard No. 108. NHTSA will not question that determination unless it appears clearly erroneous. Because of raised ridges, you deem the rubrail not as practicable a location as the slightly higher area. Paragraph S5.7.1.4.2 allows discontinuities in the side treatment as long as not less than half the side is covered and the spaces are distributed as evenly as practicable.

Although the sheeting itself must meet the performance indicated at the observation angles specified in Figure 29, there are no visibility requirements that apply to it once it is installed on a trailer. This means that the obscuring of the conspicuity treatment that begins at about 30 degrees from perpendicular under your proposed treatment is not prohibited by Standard No. 108.

Request an Interpretation

You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:

The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590

If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.

Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.