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
| Interpretations | Date |
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ID: aiam3306OpenMr. J. Bill Simpson, Simpson Sports, 22630 South Normandie Avenue, Torrance, CA 90502; Mr. J. Bill Simpson Simpson Sports 22630 South Normandie Avenue Torrance CA 90502; Dear Mr. Simpson: This responds to your May, 1980, letter asking whether the Departmen of Transportation preempts State approval programs designed to enforce State standards on equipment regulated by Federal safety standards. In a subsequent conversation with Roger Tilton of my staff, you indicated that several States require you to obtain advance approval from them prior to sale of your motorcycle helmets. You further stated that each of these advance approvals can be very costly.; The National Traffic and Motor Vehicle Safety Act of 1966 (the Act) (1 U.S.C. 138 *et* *seq*.) in section 1392(d) preempts States from having any safety standard applicable to the same aspect of performance as a Federal standard unless the State standard imposes a higher level of performance and applies only to vehicles or equipment purchased for the State's own use. The Act is silent with respect to the preemption of State enforcement procedures, such as approval schemes that require State permission prior to the sale of vehicles or equipment in their jurisdictions.; We note that the issue of advance approval schemes was litigated i *Truck Safety Equipment Inst. v. Kane*, 466 F.Supp. 1242 (D.C., Pa. 1979). In that case (copy enclosed) the court held that a State advance approval scheme was preempted by the Act. We suggest that you bring this case to the attention of the appropriate officials in the States in question. If either you or officials from those States have further questions, you can contact Mr. Tilton at 202-426-9511.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam5378OpenMr. J. L. Steffy Triumph Designs Ltd. Jacknell Road Dodwells Bridge Industrial Estate Hinckley, Leics. LE10 3BS England; Mr. J. L. Steffy Triumph Designs Ltd. Jacknell Road Dodwells Bridge Industrial Estate Hinckley Leics. LE10 3BS England; Dear Mr. Steffy: This responds to your FAX of May 5, 1994, to Taylo Vinson of this Office, requesting an interpretation of Motor Vehicle Safety Standard No. 108. You describe a motorcycle lamp 'which comprises a headlight with high and low beams and 2 symmetrically (sic) flanking front auxillary (sic) lamps possessing low beam (sic) that augment the headlight.' You ask for our comments. Paragraph S5.1.3 of Standard No. 108 permits auxiliary lighting equipment provided that it does not impair the effectiveness of the lighting equipment that is required by Standard No. 108. The vehicle manufacturer's certification of compliance with Standard No. 108 includes certification to S5.1.3 and represents its determination that the supplementary equipment does not impair the effectiveness of other lighting equipment. Unless that determination appears clearly erroneous, NHTSA will not question it. Your letter contains too little information for us to comment further. For example, we do not know whether the candela of the auxiliary lower beam lamps is higher, lower, or the same as the main lower beam of the headlamp. Nor does the letter indicate whether the supplementary lower beam lamps are extinguished when the upper beam is activated. If you have further questions, we shall be pleased to answer them. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam0480OpenMr. E. Theodore Gunaris, Chief Deputy Registrar, Registry of Motor Vehicles, The Commonwealth of Massachusetts, 100 Nashua Street, Boston, MA, 02114; Mr. E. Theodore Gunaris Chief Deputy Registrar Registry of Motor Vehicles The Commonwealth of Massachusetts 100 Nashua Street Boston MA 02114; Dear Mr. Gunaris: Thank you for your letter of September 17, 1971, asking if presen Federal regulations would preempt the Massachusetts requirement that certain outside rearview mirrors be provided with reflective material over the rear surface.; Section 103(d) of the National and Motor Vehicle Safety Act, 15 U.S.C 1392(d), states in pertinent part:; >>>'Whenever a Federal motor vehicle safety standard . . . is i effect, no State . . . shall have any authority . . . to establish . . . with respect to any motor vehicle or item of motor vehicle equipment any safety standard applicable to the same aspect of performance of such vehicle or item of equipment which is not identical to the Federal standard.'<<<; Federal Motor Vehicle Safety Standard No. 108, *Lamps, Reflectiv Devices, and Associated Equipment*, establishes requirements for reflective materials used on motor vehicles. The NHTSA considers this standard to include within its scope all reflective materials required to be used on motor vehicles to which it applies. Any State requirements that have the effect of regulating such reflective materials must therefore be identical to the relevant provisions of Standard No. 108. The Massachusetts statute that you have brought to our attention is not identical to the Federal standards relating to that aspect of performance, and must therefore be considered to be invalidated by the operation of the National Traffic and Motor Vehicle Safety Act.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam4990OpenMr. John W. Phillips Project Engineer Transportation Research Center of Ohio East Liberty, OH 43319; Mr. John W. Phillips Project Engineer Transportation Research Center of Ohio East Liberty OH 43319; Dear Mr. Phillips: This responds to your letter to this office date March 20, 1992, in which you inquired whether the Hybrid III large male test dummy, Model No. H3-95-R with 1992 pelvis upgrade, manufactured by First Technology Safety Systems, is an 'approved equivalent test device' for conducting the Federal Motor Vehicle Safety Standard (FMVSS) 202 test. I am sorry we could not respond to you on or before April 2 as you requested. Standard 202, Head Restraints (49 CFR Part 571.202), specifies requirements for head restraints to reduce the frequency and severity of neck injury in rear-end and other collisions. S4.3 of the standard requires that 'a head restraint that conforms to either (a) or (b) shall be provided' for certain seating positions. In Standard 202's demonstration procedures relating to the compliance option set forth in S4.3(a), S5.1(a) specifies use of a 'dummy having the weight and seated height of a 95th percentile adult male with an approved representation of a human, articulated neck structure, or an approved equivalent test device.' The Model H3-95-R dummy is marketed by First Technology Safety Systems as a '95th Percentile Male Hybrid III Test Dummy.' We therefore assume that it has the weight and seated height of a 95th percentile adult male. The only remaining issue of whether the dummy can be used under S5.1(a) is whether it has 'an approved representation of a human, articulated neck structure.' In the preamble to the final rule establishing Standard No. 202, NHTSA provided clarification of the term 'approved representation of a human articulated neck structure.' The agency stated that a neck structure of a test device would be approved if it could be demonstrated by technical test data that the articulation of the neck structure represented that of a human neck. NHTSA indicated that approval could only be given to a structure sufficiently described in performance parameters to ensure reliable and reproducible test data. See 33 FR 2945-2946, February 14, 1968. You did not provide any specifications or test data concerning the Hybrid III 95th percentile male dummy (Model H3-95-R). However, NHTSA conducted an extensive evaluation of the Hybrid III 50th percentile male dummy, including its neck, in the context of specifying its use (as one of two alternative 50th percentile male dummies) in Standard No. 208, Occupant Crash Protection, dummy. The specifications for the Hybrid III test dummy, for purposes of Standard No. 208, are set forth in Subpart E of 49 CFR Part 572. The specifications for the other 50th percentile male dummy used in Standard No. 208 are set forth in Subpart B of 49 CFR Part 572. We understand that the Hybrid III 95th percentile male dummy is essentially a scaled version of the Hybrid III 50th percentile male dummy. We therefore approve a Hybrid III 95th percentile male dummy for purposes of Standard 202, so long as its neck structure is essentially the same as that of the Part 572 Hybrid III test dummy, other than minor differences related to adjustments for length. For the same reasons, we approve use of a 95th percentile male version of the dummy specified in Subpart B of 49 CFR Part 572, so long as its neck structure is essentially the same as that specified in Part 572, other than minor differences related to adjustments to length. I hope the above information will be of assistance to you. If you have any further questions with regard to this matter, please feel free to contact Walter Myers of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel; |
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ID: aiam2147OpenRobert S. Raymond, Esq., Assistant Attorney General, Criminal Divison (sic), State of Maine, Department of the Attorney General, Augusta, ME 04333; Robert S. Raymond Esq. Assistant Attorney General Criminal Divison (sic) State of Maine Department of the Attorney General Augusta ME 04333; Dear Mr. Raymond: We have received copies of correspondence between you and Leonard A Fink, Washington counsel for Bombardier/Puch motorized bicycles, concerning requirements of the State of Maine for motor driven cycle headlamps. I understand that Mr. Fink as provided you with a copy of my letter of September 17, 1975 to him. Mr. Fink has asked that I write you directly concerning our views on Federal preemption of State motor vehicle safety standards.; At issue is whether the State of Maine may continue to requir motorcycles of 5 horsepower or less to be equipped with multiple beam headlamps. In my letter to Mr. Fink I stated:; >>>'Any motorcycle with 5 horsepower or less manufactured on or afte January 1, 1969, may be equipped with either a single or multiple beam headlamp (Table III, Standard No. 108, incorporating by reference SAE Standard J584, *Motorcycle and Motor Driven Cycle Headlamps*, April 1964. See Table I of J584. This means, pursuant to 15 U.S.C. 1392(d) that a State is preempted from requiring a motorcycle with 5 horsepower or less to be equipped with a multiple beam headlamp if its manufacturer has equipped it with a single beam one'.<<<; You replied to Mr. Fink on November 7, 1975 that >>>'Table I appears to be inconclusive . . . . The most reasonabl interpretation . . . is that motor driven cycles at high beam frequently utilize both the upper beam of the multiple beam light and a additional single beam light, whereas motor driven cycles at low beam may use the lower beam of the multiple lights (Table II of J584). At any rate, I have not found any clear preemptive language such as we find with regard to turn signal lamps in Standard No. 108 S 4.1.1.26.'<<<; There are actually four different permissible lighting configuration available for motor driven cycles. The 'multiple beam light and an additional single beam light' to which you refer is one of them, specifically the 'one 5 3/4 inch Type 1 and one 5 3/4 inch Type 2 sealed beam units' referred to in SAE J584's *General Requirement*. But the photometrics of Table I do not refer to this configuration, whose photometrics are those of J579. As a practical matter motor driven cycles will rarely if ever be equipped with more than one headlamp because of the severe drain on their low power reserve. In recognition of the limited generating capability of motor cycles with 5 horsepower or less, J584 does allow use of a single beam headlamp as the sole forward lighting source. The texts of the sections on *Beam Aim During Photometric Test* and *At-Focus Tests* refer specifically to test methods for single beam headlamps, and while the standard could be even more specific, its requirements appear to be generally understood by manufacturers and law enforcement officials. It is not a prerequisite for preemption that there be language in the body of Standard No. 108 specifying allowable headlamp systems for motor driven cycles. Where, as here, the area of motor driven cycles. Where, as here, the area of motor driven cycle headlighting is clearly covered by Standard No. 108, a State must allow all four headlighting systems and cannot require only one of them.; If Maine officials would like the NHTSA to consider changing thes existing Federal requirements for motor-driven cycles, they should submit a petition for rulemaking pursuant to 49 CFR Part 552 for an amendment to Standard No. 108.; If you have any further questions I would be pleased to answer them. Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam2517OpenMr. Richard Hadley, Chief Product Engineer, Harman International Industries, Inc., P.O. Box 329, Bolivar, Tennessee 38008; Mr. Richard Hadley Chief Product Engineer Harman International Industries Inc. P.O. Box 329 Bolivar Tennessee 38008; Dear Mr. Hadley: This responds to your February 2, 1977, request for approval of Harma Industries procedure for measuring the average reflectance value of its 'Nite-Ban' rearview mirror. You describe the 'Nite-Ban' as a mirror glass having a band of low reflectance horizontal to the horizon and centered between the top and bottom of the glass. You request confirmation that the 'Nite-Ban' mirror conforms to the requirements of Standard No. 111, *Rearview Mirrors*.; Paragraph S11 of Standard No. 111, 49 CFR 571.111, specifies that th *average* reflectance value of any mirror required by the standard shall be at least 35 percent, determined in accordance with SAE Recommended Practice J964a. If the average reflectance value of the reflective surface of a 'Nite-Ban' mirror is at least 35 percent, the mirror is acceptable under Standard No. 111. However, it is the responsibility of the manufacturer to determine if an item of motor vehicle equipment complies with applicable safety standards. The agency cannot grant prior approval.; Further, the agency cannot approve a manufacturer's test procedures i advance. Therefore, we cannot confirm that your proposed procedure for measuring the average reflectance value of 'Nite-Ban' mirrors is an acceptable procedure. It is the manufacturer's responsibility to exercise sound engineering judgement in determining that its vehicle meet the performance levels prescribed in the safety standards.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam2560OpenMr. R. W. Hildebrandt, Group Director of Engineering, Heavy Vehicle Systems Group, The Bendix Corporation, 901 Cleveland Street, Elyria, OH 44035; Mr. R. W. Hildebrandt Group Director of Engineering Heavy Vehicle Systems Group The Bendix Corporation 901 Cleveland Street Elyria OH 44035; Dear Mr. Hildebrandt: This responds to Bendix Corporation's March 29, 1977, request fo confirmation that the manual adjustment of automatic adjusters is acceptable following the burnish procedures of Standard No. 121, *Air Brake Systems*, at the option of the manufacturer.; The procedure that you recommend is not permitted by any provision o Standard No. 121. The NHTSA would consider some provision to deal with the overadjustment of automatic adjusters upon receipt of technical data showing justification for such action. Based on consideration of the data received and a petition for amendment, the agency could commence a rulemaking proceeding in accordance with established procedures.; I have enclosed a copy of a similar interpretation made to Rockwel International.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam2130OpenMr. Bruce J. Smith, Engineering Services Department, Bucyrus- Erie Company, South Milwaukee, WI 53172; Mr. Bruce J. Smith Engineering Services Department Bucyrus- Erie Company South Milwaukee WI 53172; Dear Mr. Smith: This responds to Bucyrus-Erie's October 8, 1975, suggestion that th terms 'unloaded vehicle weight' and 'passenger-carrying capacity' be defined in 49 CFR S 571.3 to reflect explanations of them that appeared in the preamble of recent NHTSA rulemaking on Standard No. 121, *Air Brake Systems*. (40 FR 38160, August 27, 1975). You believe that removable portions of a vehicle that are essential to its function (e.g., the boom on a mobile crane) should not be considered part of the vehicle's 'cargo' as that term is used in the present definition of unloaded vehicle weight.; The NHTSA explained in the preamble to which you refer that th unloaded vehicle weight is easily determined by, in most cases, subtracting the weight of cargo and occupants from the gross vehicle weight rating (GVWR) assigned to the vehicle by the manufacturer. We believe that the term 'cargo' clearly indicates that the manufacturer must only subtract the weight of commodities or freight that the vehicle is designed to carry as a transportation function. Presumably the manufacturer of a mobile crane would have no difficulty in concluding under the present definition of 'unloaded vehicle weight' that its vehicle does not transport 'cargo' and that no value must be subtracted from the GVWR on this account.; It does appear that the term 'passenger-carrying capacity' used i Standard No. 121 could be expanded to reflect the exclusion of the operating crew from consideration as passengers. In response to your request we are considering an amendment of S3 to make this concept clearer.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam3371OpenMr. Stephen E. Mulligan, International Harvester, 401 North Michigan Avenue, Chicago, IL 60611; Mr. Stephen E. Mulligan International Harvester 401 North Michigan Avenue Chicago IL 60611; Dear Mr. Mulligan: This is in response to your letter of October 1, 1980, in which you as whether compliance with 49 CFR 567, Certification, will satisfy the requirements of S4.3 of Federal Motor Vehicle Safety Standard No. 115, 49 CFR 571.115.; Section 4.3 of Federal Motor Vehicle Safety Standard No. 115 require that the vehicle identification number (VIN) 'appear clearly and indelibly upon either a part of the vehicle other than the glazing that is not designed to be removed except for repair or upon a separate plate or label which is permanently affixed to such a part.' S4.3.1 requires each character to appear in a capital, sans serif typeface. In the case of passenger cars and trucks of 10,000 pounds or less GVWR, each character must have a minimum height of 4 mm. S4.4 specifies that the VIN for passenger cars and trucks of 10,000 pounds or less GVWR shall be located within the passenger compartment.; Section 567.4 of Part 567, Certification (49 CFR 567), requires tha the certification label be permanently affixed to the vehicle, and display the vehicle identification number. Consequently, for all vehicles except passenger cars and trucks of 10,000 pounds or less GVWR, compliance with S 567.4 of Part 567 would also effect compliance with S4.3 of Standard No. 115 so long as capital, sans serif typeface was used.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2999OpenMr. R. M. Premo, Vehicle Safety Activities, Sheller-Globe Corporation, 3555 St. Johns Road, Lima, OH 45804; Mr. R. M. Premo Vehicle Safety Activities Sheller-Globe Corporation 3555 St. Johns Road Lima OH 45804; Dear Mr. Premo: This is in response to your letter of February 15, 1979, concerning th definition of 'forward control' vehicle contained in 49 CFR 571.3. Your specific concern is how to measure a vehicle's length to determine if 'the steering wheel hub is in the forward quarter of the vehicle length.'; Overall vehicle length should be determined by measuring the maximu longitudinal distance between the foremost point on the front bumper face bar and the rearmost point on the rear bumper face bar. In the context of the Part 581 Bumper Standard (49 CFR 581), the agency considers bumper guards to be part of the bumper face bar if they are contacted by the impact ridge of the pendulum test device used in compliance testing (43 F.R. 20804, May, (sic) 15, 1978). For the purposes of determining vehicle length, the agency will consider bumper guards as a part of the vehicle bumper face bar and thus included in the measurement of vehicle length. Components such as a permanent or fold-down step which are not associated with the bumper system's function are not considered part of the bumper face far for the purposes of Part 581 Bumper Standard (43 F.R. 40230, Sept. 11, 1978). Therefore, the agency will not consider a permanent or fold-down step as a part of the bumper face bar for the purposes of determining vehicle length.; I have enclosed for your information a notice of proposed rulemakin which would extend Standards No. 201, 203 and 204 to forward control vehicles. The notice also states the agency's intention to eliminate the forward control exemption found in other Federal motor vehicle safety standards.; If you have any further questions, please let me know. Sincerely, Frank Berndt, Acting Chief Counsel |
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.