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: aiam4249OpenMs. Barbara J. Kelleher, CRS Research, P.O. Box 313, Buffalo, NY 14226; Ms. Barbara J. Kelleher CRS Research P.O. Box 313 Buffalo NY 14226; Dear Ms. Kelleher: This responds to your letter to Stephen Kratzke of my staff, seeking a interpretation of Standard No. 213, *Child Restraint Systems* (49 CFR S571.213). Specifically, you stated that a client planned to produce two child restraint models whose harness and crotch straps would be integral parts of a movable shield. You stated your belief that these straps were an integral part of the shield within the meaning of section S6.1.2.3.1(c) of Standard No. 213. Accordingly, you asked that this agency permit these straps to be attached during the Configuration II testing required by section S6.1.2.1.2. You stated that a similar request for harness attachment was 'granted' to the Collier-Keyworth Company.; First, I would like to make clear that this agency does not gran requests by manufacturers to avoid following the compliance test procedures specified in Standard No. 213. We interpret the requirements of Standard No. 213 as they apply to particular factual situations. When those same factual situations arise again, our interpretation of the requirements is the same, regardless of which manufacturer is involved.; For your information, I have enclosed a copy of a July 3, 1985, lette this agency sent to Mr. Frederick Locker, addressing whether a proposed Collier-Keyworth child restraint could attach its belts during the Configuration II testing. We concluded that belts that are attached to and not easily removed from a movable shield are integral parts of the shield, within the meaning of section S6.1.2.3(c). This conclusion means that those belts may be attached during the Configuration II testing.; Judging by the pictures enclosed with your letter, it appears that eac of the two child restraint models designed by your client also has belts that are attached to and not easily removed from the movable shield. If our belief is correct, those belts could be attached during the Configuration II testing.; If you have any further questions or need more information on thi subject, please contact Mr. Kratzke at this address or by telephone at (202) 366-2992.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam4641OpenCONFIDENTIAL; CONFIDENTIAL; Dear: With respect to the interpretation furnished you on July 21 l989, you have requested the following clarification in your letter of the 28th: that the provisions of paragraph S7.4 of Standard No. 108 that relate to filament usage do not apply to the headlamp system previously described. You have also confirmed that this system is designed to conform to all other requirements of Standard No. 108 'including photometric, special wiring, mechanical aim, environmental and marking requirements. Paragraph S7.4 describes a variety of headlighting systems which come under the heading of 'integral beam systems.' The beams in these systems will be produced by 'beam contributors' (S7.4(a)(3)), headlamps containing 'two light sources' (S7.4(b)), or headlamps containing 'a single filament' (S7.4(c)). The arc tubes in the system you describe would appear to be 'beam contributors' within the meaning of S7.4, and the filament language of paragraph S7.4 would not apply to this particular type of integral beam headlighting system. We will honor your continuing request that your name and those of your firm and client be deleted from the copy made publicly available. Sincerely, Stephen P. Wood Acting Chief Counsel; |
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ID: aiam2594OpenMr. Kenneth R. Brennan, Hendrickson Mfg. Co., 8001 West Forty-Seventh Street, Lyons, IL 60534; Mr. Kenneth R. Brennan Hendrickson Mfg. Co. 8001 West Forty-Seventh Street Lyons IL 60534; Dear Mr. Brennan: This responds to your May 17, 1977, letter asking for an interpretatio of 'unloaded vehicle weight.' You are interested specifically in whether cranes and drill rigs are included in the computation of a vehicle's 'unloaded vehicle weight.'; 'Unloaded vehicle weight' is defined in the Code of Federa Regulations, Title 49, Part 571.3 to mean; >>>the weight of a vehicle with maximum capacity of all fluid necessary for operation of the vehicle, but without cargo or occupants.<<<; Through a previous interpretation (copy enclosed), the National Highwa Traffic Safety Administration (NHTSA) has determined that the 'weight of the vehicle' includes the weight of those accessories that are installed on a vehicle before delivery and are not ordinarily removed.; From the description of the apparatus to which you refer in you letter, it would appear that the cranes or drilling rigs are not normally removed from the vehicle when not in use. Further, the removal of these pieces of equipment appears to be a cumbersome task. Accordingly, it is the opinion of the NHTSA that the weight of the equipment to which you refer would be part of the 'weight of the vehicle' and, therefore, would be included in the computation of the 'unloaded vehicle weight.'; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3100OpenMr. Daniel I. Borovik, Director of Development and Planning, Essex Group, Wire Assembly Division, 6233 Concord Avenue, Detroit, MI 48211; Mr. Daniel I. Borovik Director of Development and Planning Essex Group Wire Assembly Division 6233 Concord Avenue Detroit MI 48211; Dear Mr. Borovik: This is in reply to your letter of August 7, 1979, asking whethe 'trailer warning lamps [should] flash or be steady-burning' when the towing vehicle's hazard warning system is actuated and the service brakes are applied.; Federal Motor Vehicle Safety Standard No. 108 does not require trailer to be equipped with hazard warning signal lamps, and you may design your trailer tow electrical package without reference to it. Lack of Federal regulation in this area, however, means that each State may set its own requirements, and you should ascertain whether such exist before finalizing your design.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0275OpenMr. James O. Blakenship, Director of CentiMile Programs, Long Mile Rubber Company, 155 South Court - Exchange Park, P.O. Box 45228, Dallas, Texas 75235; Mr. James O. Blakenship Director of CentiMile Programs Long Mile Rubber Company 155 South Court - Exchange Park P.O. Box 45228 Dallas Texas 75235; Dear Mr. Blakenship: This is in reply to your letter to Mr. Van Orden dated May 20, 1971. Tires retreaded prior to the effective date of the retreaded standar (January 1, 1972) are not permitted to contain the DOT symbol on the tire. If you have marked your matrices with the symbol, I suggest you buff the letters off the tire after it is retreaded, or remove the symbol from the matrix, or fill in that portion of the matrix.; The retreading of tires without the DOT markings before the effectiv date of the standard is permissible.; Sincerely, Lawrence R. Schneider, Acting Chief Counsel |
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ID: aiam2138OpenMr. Robert L. Webber, Vice President, American Sports Co. Inc., P. O. Box 5603, 2970 East Maria Street, Compton, CA 90221; Mr. Robert L. Webber Vice President American Sports Co. Inc. P. O. Box 5603 2970 East Maria Street Compton CA 90221; Dear Mr. Webber: This is in response to your request of November 21, 1975, for a opinion regarding requirements for certifying universal sized helmets pursuant to Federal Motor Vehicle Safety Standard No. 218.; The requirements of Standard No. 218, *Motorcycle Helmets*, apply t helmets that fit headform size C. This includes the case where, by means of an adjusting mechanism supplied by the manufacturer for the purpose of permitting adjustment to headform size C, the helmet can readily be made to fit headform size C. Thus, any helmet that the manufacturer intends for use by persons with heads in the size C range must meet the requirements of the standard, including the requirement to affix the label required by section 5.6.1 of the standard.; The 'universal' helmet described in your letter seems to fall withi these guidelines in that it is intended to fit, *inter* *alia*, the size C headform. Therefore, notwithstanding the fact that it may also be adjusted to fit other size headforms, it should meet the requirements of FMVSS No. 218, including the labeling requirements.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2139OpenMr. Robert L. Webber, Vice President, American Sports Co. Inc., P. O. Box 5603, 2970 East Maria Street, Compton, CA 90221; Mr. Robert L. Webber Vice President American Sports Co. Inc. P. O. Box 5603 2970 East Maria Street Compton CA 90221; Dear Mr. Webber: This is in response to your request of November 21, 1975, for a opinion regarding requirements for certifying universal sized helmets pursuant to Federal Motor Vehicle Safety Standard No. 218.; The requirements of Standard No. 218, *Motorcycle Helmets*, apply t helmets that fit headform size C. This includes the case where, by means of an adjusting mechanism supplied by the manufacturer for the purpose of permitting adjustment to headform size C, the helmet can readily be made to fit headform size C. Thus, any helmet that the manufacturer intends for use by persons with heads in the size C range must meet the requirements of the standard, including the requirement to affix the label required by section 5.6.1 of the standard.; The 'universal' helmet described in your letter seems to fall withi these guidelines in that it is intended to fit, *inter* *alia*, the size C headform. Therefore, notwithstanding the fact that it may also be adjusted to fit other size headforms, it should meet the requirements of FMVSS No. 218, including the labeling requirements.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4148OpenMr. Roland L. Lafleur, 1155 W. Grolee St., Opelousas, LA 70570; Mr. Roland L. Lafleur 1155 W. Grolee St. Opelousas LA 70570; Dear Mr. Lafleur: This is in reply to your letter of May 5, 1986, to our former Chie Counsel, Jeffrey Miller, asking about comparative costs of a center high-mounted stop lamp. You read that the cost of such a lamp was $4 to $7, but in fact it cost you $136.18, tax included, to have one installed on your 1984 Cadillac.; The figures of $4 to $7 represent the agency's conclusions as to th cost to a vehicle manufacturer to install the new lamp as standard equipment when its installation became mandatory for new vehicles. As the new requirement does not extend to aftermarket equipment such as the lamp you bought for your 1984 Cadillac, the agency's cost estimates should not be read as applying to it. Also, our estimate was for the 'average' vehicle. Costs will vary by manufacturer and by carline within a given manufacturers' (sic) fleet according to the particular design and placement chosen. In spite of your dissatisfaction over the cost you have nevertheless wisely equipped your car with a safety device which should lessen the likelihood of expensive rear end collisions and the injuries to passengers that can occur. We appreciate your interest in the lamp.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1989OpenMr. Manuel M. Ellenbogen, Supervisor, Export Sales & Licensing, International-Automotive, The Budd Company, 2450 Hunting Park Avenue, Philadelphia, PA 19132; Mr. Manuel M. Ellenbogen Supervisor Export Sales & Licensing International-Automotive The Budd Company 2450 Hunting Park Avenue Philadelphia PA 19132; Dear Mr. Ellenbogen: This is in response to your letter of July 8, 1975, asking whic standards might be affected by the mounting of a tail lamp in the elastic skin of a bumper.; Motor Vehicle Safety Standard No. 215, *Exterior Protection* prescribes barrier and pendulum impact tests to which vehicles must be subjected without incurring certain types of damage. Included in the list of safety systems that must remain undamaged are lamps and reflective devices. S5.3.1 of Standard 215 states that each lamp or reflective device, except license plate lamps, must remain free of cracks and comply with the applicable visibility requirements of S4.3.1.1 of Standard No. 108, *Lamps, Reflective Devices, and Associated Equipment*.; The manufacturer should be aware that placement of a tail lamp in th elastic skin of a bumper might expose it to damage during Standard 215 compliance testing.; For your information, I have enclosed copies of the current Standar No. 215, the proposed Part 580 bumper damageability standard, and Standard No. 108.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4847OpenMr. Chris Lawrence Chang & Lawrence P.O. Box 105-55 Taipei Taiwan R.O.C.; Mr. Chris Lawrence Chang & Lawrence P.O. Box 105-55 Taipei Taiwan R.O.C.; Dear Mr. Lawrence: This is in reply to your letter to Dr. Burgett o this agency. Though dated January 5, 1991, we did not receive it until March 7. With respect to your wish to produce an electronic sign board for installation in the rear window area, or on the rear, of a passenger car, I enclose a copy of an interpretation of this Office dated August 17, l989, regarding such a device. Although the interpretation is restricted to an interior-mounted electronic sign board, our conclusion would not be changed were the device to be mounted on the outside of the rear of the vehicle. In that location, and as an item of original equipment, we believe that it would impair the effectiveness of the required rear lighting equipment by its potential to distract following drivers from the signals sent by the rear lamps when they and the sign board are operated simultaneously. Although the considerations for aftermarket devices are expressed differently, as explained in the August l989 letter, the potential for distraction would appear to create a partial inoperability of the rear lamps within the meaning of the prohibition. Sincerely, Paul Jackson Rice Chief Counsel Enclosure; |
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.