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: aiam5271OpenMr. Jack McIntyre Vice President Tie Tech Inc. Post Office Box 5226 Lynnwood, WA 98046-5226; Mr. Jack McIntyre Vice President Tie Tech Inc. Post Office Box 5226 Lynnwood WA 98046-5226; "Dear Mr. McIntyre: This responds to your letter in which you withdre your petition for rulemaking of August 18, 1993, and requested an agency interpretation instead. You referred to the final rule issued by this agency on January 15, 1993 (58 FR 4585), which amended Federal Motor Vehicle Safety Standard (FMVSS) 222. Specifically, paragraph S5.4.2.(a)(1) of the amendment provides that wheelchair securement devices composed of webbing or straps must meet the requirements for Type I safety belt systems specified in S4.2, among others, of FMVSS 209. You stated that there is no need to specify a minimum width for wheelchair securement belts and that the current industry standard for securement belts is a 1-inch polyester belt. Finally, you stated that the 1-inch polyester belts have less stretch than the 1.8-inch nylon belts and that the 1-inch belts are easier and less cumbersome to connect to a wheelchair. Paragraph S4.2(a), FMVSS 209, provides that seat belt webbing cannot be less than 1.8 inches wide, 'except for portions that do not touch a 95th percentile adult male with the seat in any adjustment position and the seat back in the manufacturer's nominal design riding position . . . .' That means that seat belt webbing must be at least 1.8 inches wide whenever it touches the person of the seat occupant. The width of webbed wheel chair securement belts that do not touch the persons of the chair occupants is not specified in any standard. Therefore, wheel chair securement belts can be 1 inch or some other width, so long as they do not touch the persons of the chair occupants and meet the other requirements of applicable standards. I hope this clarifies this matter for you. If you have any further questions or need any further information, please feel free to contact Walter Myers of my staff at this address or at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam4876OpenMs. Vicki Haudler 4636 S. Cedar Lake Rd. St. Louis Park, MN 55416; Ms. Vicki Haudler 4636 S. Cedar Lake Rd. St. Louis Park MN 55416; "Dear Ms. Haudler: This responds to your letter seeking furthe information about a possible determination to be made by the Secretary of Transportation under Federal Motor Vehicle Safety Standard No. 208 (49 CFR 571.208). S4.1.4.1 of Standard No. 208 provides that cars manufactured on or after September 1, 1989 must be equipped with automatic crash protection. Vehicles equipped with automatic crash protection protect their occupants by means that require no action by vehicle occupants. Compliance with the minimum performance requirements of Standard No. 208 is determined in a dynamic crash test. That is, a vehicle must comply with specified injury criteria, as measured on a test dummy, when tested by this agency in a 30 mph barrier crash test. The two types of automatic crash protection currently offered on new passenger cars are automatic safety belts (which help to assure belt use) and air bags (which supplement safety belts and offer some protection even when safety belts are not used). As you noted in your letter, S4.1.5 of Standard No. 208 provides that: 'If the Secretary of Transportation determines, by not later than April 1, 1989, that state mandatory safety belt usage laws have been enacted that meet the criteria specified in S4.1.5.2 and that are applicable to not less than two-thirds of the total population . . ., the automatic restraint requirements will not go into effect .' You asked whether the Secretary ever made a determination under S4.1.5 regarding State safety belt use laws. The answer is no. Under S4.1.5, the Secretary was not required to make any determination about any State safety belt laws. In fact, the Secretary never did so. Because no determination was made under S4.1.5, the automatic restraint requirements went into effect as of September 1, 1989 for all passenger cars. I have returned the self-addressed, stamped envelope you enclosed in your letter. Good luck in your legal career. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam0246OpenMr. Fred C. Zimmer, Evans, Gentithes and Meermans, 220 East Market Street, Warren, Ohio 44481; Mr. Fred C. Zimmer Evans Gentithes and Meermans 220 East Market Street Warren Ohio 44481; Dear Mr. Zimmer: Pursuant to the National Traffic and Motor Vehicle Safety Act of 1966 15 USC 1381 et. seq., the National Highway Safety Bureau issued Federal Motor Vehicle Safety Standard 109 (FMVSS-109). This standard set forth strength, bead unseating, endurance, high speed and labeling requirements for passenger car tires manufactured on or after January 1, 1968, for use on cars manufactured after 1948. This standard does not apply to other types of tires. A copy of FMVSS-109 is enclosed. A manufacturer self-certifies that the tire meets the minimum requirements of the standard by molding the symbol 'DOT' into the tire. Subsequent identification of the tire as a 'second' would not negate the certification.; The National Highway Safety Bureau is currently testing many bran /size tires to verify their conformance to Federal Motor Vehicle Safety Standard No. 109. The tests are conducted at independent laboratories under contract to the Government. Results of these tests are released to the public in a monthly summary.; The test results does not reflect the Bureau's position on the matter Favorable test results should not be interpreted as necessarily establishing that a specific tire is in conformity with the standard, similarly, unfavorable test results should not be interpreted as establishing nonconformance.; Copies of individual test reports con be obtained, for a fee of $3.0 per publication, from the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. Should sufficient data be left remaining on the tire in question for proper identification you may wish to avail yourself of this service.; There is an organization which could possibly furnish you with the nam of an individual capable of analyzing the causes of tire failures. Their name and address is: America Council of Independent Laboratories, Incorporated. 1714 West Capitol Avenue, Houston, Texas 77007.; I trust this information will be useful to you, and I appreciate thi opportunity to be of assistance.; Sincerely, Francis Armstrong, Director, Office of Compliance, Moto Vehicle Programs; |
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ID: aiam2807OpenMs. Susan H. Soodek, 1025 Connecticut Avenue, N.W., Washington, DC 20036; Ms. Susan H. Soodek 1025 Connecticut Avenue N.W. Washington DC 20036; Dear Ms. Soodek: This responds to your recent letter asking whether Federal Safet Standard No. 205 specifies requirements limiting the reflectivity of glazing materials. You are concerned with the lack of uniformity in state laws that prohibit nontransparent or reflective windows in motor vehicles.; The stated purpose of Safety Standard No. 205, *Glazing Materials*, i to reduce injuries resulting from impact to glazing surfaces, to ensure a necessary degree of transparency in motor vehicle windows for driver visibility, and to minimize the possibility of occupants being thrown through the vehicle windows in collisions. The standard does not prohibit reflective glazing, nor does it specify requirements that would limit the degree of reflectivity of glazing materials.; Since reflectivity is not an aspect of performance governed by Federa safety standards, state laws concerning glazing reflectance would not be preempted by Standard No. 205. Safety Standard No. 205 does, however, specify requirements for the luminous transmittance of glazing materials for use in motor vehicles. Therefore, state laws prohibiting nontransparent windows would be preempted if they attempted to regulate the glazing manufacturer or the vehicle manufacturer (15 U.S.C. 1392(d)). State regulations applicable to the vehicle owner or user would not be preempted, on the other hand, since the Federal regulation is only applicable to the manufacturer. Therefore, a state law could prohibit the application of a nontransparent decal on a window by a vehicle owner, for example.; I am enclosing a copy of the California Highway Patrol petition fo rulemaking regarding glazing abrasion requirements and glazing reflectivity. A notice concerning this petition will be issued at some time in the near future.; I must point out that our statutory authority requires all safet standards to be reasonable, objective and to meet the need for motor vehicle safety. The agency cannot, therefore, regulate an aspect of motor vehicle performance or design if there is no data or evidence indicating that a safety problem exists.; I hope this has been responsive to your inquiry. Please contact Hug Oates of my office if you have any further questions.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1378OpenHonorable Charles H. Percy, United States Senate, Washington, DC 20015; Honorable Charles H. Percy United States Senate Washington DC 20015; Dear Senator Percy: This is in reply to your communication of January 3, 1974, forwardin to us correspondence dated November 29, 1973, from Mr. Bruce Motyka of Des Plaines. Mr. Motyka requests information regarding laws relating to pickup truck and camper weight limits, laws or studies relating to the sale of trucks exceeding GVW (Gross Vehicle Weight) rate minimums, and regulations or studies regarding maximum weights for tires.; The NHTSA has issued regulations relating to the installation o campers onto pickup trucks. Motor Vehicle Safety Standard No. 126 'Truck camper loading' (49 CFR S 571.126) requires each camper to bear a permanent label containing information on its maximum loaded weight. The standard also requires each camper to be furnished with an owner's manual that contains information on total camper weight, the selection of an appropriate pickup truck, appropriate methods of camper loading, how to determine the camper's center of gravity and where it should be placed in the truck cargo area. A companion 'Consumer Information' regulation, 'Truck camper loading' (49 CFR S 575.103) requires that written information be provided at the sale of each truck capable of being equipped with a slide-in camper that deals with the correct installation of a slide-in camper in that vehicle. This information is also required to be available in dealers' showrooms for retention by prospective purchasers of such trucks.; Other NHTSA regulations (49 CFR Part 567, 'Certification') requir every motor vehicle, including pickup trucks, to be labeled, usually on the driver's door or door jam, with its gross vehicle weight rating, and the gross axle weight rating for each axle. Each of these ratings is intended to be based on the weight of a fully loaded vehicle, as determined by the vehicle's manufacturer. While it is possible for manufacturers proposed course of action appears to have the aim of generating dissatisfaction with Federal tire regulations among dealers and distributors, and could, by lessening cooperation at the retail level, interfere with your client's ability to fulfill its obligations under the regulations.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam1380OpenHonorable Charles H. Percy, United States Senate, Washington, DC 20015; Honorable Charles H. Percy United States Senate Washington DC 20015; Dear Senator Percy: This is in reply to your communication of January 3, 1974, forwardin to us correspondence dated November 29, 1973, from Mr. Bruce Motyka of Des Plaines. Mr. Motyka requests information regarding laws relating to pickup truck and camper weight limits, laws or studies relating to the sale of trucks exceeding GVW (Gross Vehicle Weight) rate minimums, and regulations or studies regarding maximum weights for tires.; The NHTSA has issued regulations relating to the installation o campers onto pickup trucks. Motor Vehicle Safety Standard No. 126 'Truck camper loading' (49 CFR S 571.126) requires each camper to bear a permanent label containing information on its maximum loaded weight. The standard also requires each camper to be furnished with an owner's manual that contains information on total camper weight, the selection of an appropriate pickup truck, appropriate methods of camper loading, how to determine the camper's center of gravity and where it should be placed in the truck cargo area. A companion 'Consumer Information' regulation, 'Truck camper loading' (49 CFR S 575.103) requires that written information be provided at the sale of each truck capable of being equipped with a slide-in camper that deals with the correct installation of a slide-in camper in that vehicle. This information is also required to be available in dealers' showrooms for retention by prospective purchasers of such trucks.; Other NHTSA regulations (49 CFR Part 567, 'Certification') requir every motor vehicle, including pickup trucks, to be labeled, usually on the driver's door or door jam, with its gross vehicle weight rating, and the gross axle weight rating for each axle. Each of these ratings is intended to be based on the weight of a fully loaded vehicle, as determined by the vehicle's manufacturer. While it is possible for manufacturers proposed course of action appears to have the aim of generating dissatisfaction with Federal tire regulations among dealers and distributors, and could, by lessening cooperation at the retail level, interfere with your client's ability to fulfill its obligations under the regulations.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam0945OpenMrs. Lewis Polin, 1912 Nester Street, Philadelphia, PA 19115; Mrs. Lewis Polin 1912 Nester Street Philadelphia PA 19115; Dear Mrs. Polin: This is in reply to your letter to our Region III office in which yo requested information on infant car seats and regulations affecting the manufacture of such seats.; Enclosure 1 is a copy of Federal Motor Vehicle Safety Standard No. 213 Child Seating Systems, along with a recent amendment to the standard. The effective date of this standard was April 1, 1971. All child car seats which both seat and restrain a child in a motor vehicle are now required by law to comply with the requirements of this standard. This regulation requires the date of manufacture to be placed on each seat along with recommendations for its use. Child seating systems are recommended for use by children from approximately eight to nine months to three to four years of age.; The National Highway Traffic Safety Administration is presentl developing a proposed amendment to the existing standard which will require dynamic tests of all child restraints and will regulate infant restraints which are not presently covered by Standard No. 213. However, it is not anticipated that this amendment will become effective in the near future.; Enclosures 2 and 3 are copies of press releases notifying consumers o devices which have failed to pass Standard No. 213, and of the action the manufacturers are taking to correct the situation. Additionally, we are enclosing a copy of a consumer information booklet entitled, 'What To Buy In Child Restraint Systems.' We hope this information will assist you.; We do not endorse or advocate any specific product, but rather develop issue, and enforce minimum safety standards for consumer protection. In the final analysis, the consumer should select a restraint which best fits his particular needs. Many practical considerations may affect the usage of a device, for example, the activity level of the child, portability of the device, and ease of attachment. These are all factors which the buyer of a child restraint system should consider in making his selection.; Thank you for your interest in motor vehicle safety. Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam4526OpenMr. Paul Scully Vice President Peterson Manufacturing Co. 4200 East 135th St. Grandview, MO 64030; Mr. Paul Scully Vice President Peterson Manufacturing Co. 4200 East 135th St. Grandview MO 64030; Dear Mr. Scully: This is in reply to your letter of April 22, l988 asking for a clarification of a letter that this Office sent Wesbar Corporation on March 16, 1988, with respect to the term 'effective projected luminous area.' Wesbar had asked whether it could include the 'illuminated (by the turn signal bulb) reflex reflector portion of the turn signal lens' (Wesbar's language) in its calculation of the l2 square inch minimum effective projected luminous area required by S4.1.1.7 of Safety Standard No. 108. We replied that it could, assuming that the light shines through the reflector. You have pointed out that although a small amount of light escapes through a reflex reflector, the reflector is designed to return light from an outside source, rather than to direct light from a source inside the lamp, and that heretofore agency interpretations (e.g. on October 28, 1970, and October 28, 1979) had expressly excluded reflex reflectors from areas included in the calculation of effective projected luminous area. Reflex reflectors are also excluded from the term by SAE J387 Terminology. We appreciate your calling this matter to our attention. Previous interpretations by this Office clearly indicate that a 'reflex reflector' is not to be included in the calculation of effective projected luminous area. We also note that the SAE definition (paragraph 2, SAE J594f, January l977) is incorporated by reference into Standard No. 108, stating that this item of equipment is one that provides an indication of vehicle presence by reflected light (rather than projected light). We are providing a copy of this letter to Wesbar so that it will be apprised of our reevaluation, and our conclusion that the reflex reflector portion of a lens cannot be included in the calculations of the projected luminous lens area. I hope this clarifies the matter for you. Sincerely, Erika Z. Jones Chief Counsel; |
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ID: aiam4242OpenMr. Tim O. Edwards, Safety Specialist, Kansas Department of Transportation, Bureau of Personnel Services, 7th Floor, State Office Building, Topeka, KS 66612; Mr. Tim O. Edwards Safety Specialist Kansas Department of Transportation Bureau of Personnel Services 7th Floor State Office Building Topeka KS 66612; Dear Mr. Edwards: I am writing in response to your recent inquiry concerning interio over-head luggage racks on school buses. Your first question seeks this Agency's opinion on whether interior luggage racks on school buses should be considered 'projections likely to cause injury' under the National Minimum Schoolbus Standards. These standards are recommendations by the National Conference on School Transportation (NCST), and are not developed by NHTSA. Requests for interpretation of these Standards should be mailed to the Interpretation Committee, addressed to:; >>>Mr. Norman Loper, Coordinator of Pupil Transportation, Alabam Department of Education, 304 Dexter Avenue, Montgomery, AL 36130<<<; Requests for modification to these Standards and development of ne Standards should be directed to the chairman of the Interim Committee, addressed to:; >>>Mr. Bill G. Loshbough, Asst. State Supt. for Transportation, Dept of Education, Education Bldg., Santa Fe, NM 87501-2786<<<; In response to your second question, there are no federal standards o regulations which specifically address the issue of over-head luggage racks on school buses. However, Federal Motor Vehicle Safety Standard No. 222, 49 Code of Federal Regulations (CFR) S571.222 addresses the issue of school bus passenger seating and crash protection. Specifically, S5.3.1 of that standard establishes the head protection zones. As defined in S5.3.1.1, that zone extends up to a horizontal plane 40 inches above the seating reference point. If the luggage rack were to be located within the head protection zone, the rack would have to meet the head form impact requirement in S5.3.1.2 and the head form force distribution requirement in S5.3.1.3.; Please feel free to contact this office if you have any othe questions.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam3758OpenMr. H. Nakaya, Office Manager, Mazda (North America), Inc., 23777 Greenfield Road, Suite 462, Southfield, MI 48075; Mr. H. Nakaya Office Manager Mazda (North America) Inc. 23777 Greenfield Road Suite 462 Southfield MI 48075; Dear Mr. Nakaya: This responds to your letter of August 25, 1983, requesting a interpretation of the requirements of Standard No. 201, *Occupant Protection in Interior Impact*. Your specific questions concern the application of the requirements of S3.5.1(b) of the standard to an armrest.; The answers to your four questions are as follows: A) The requirements of S3.5.1(b), as with the requirements o S3.5.1(a), apply to the whole area of an armrest. In contrast, the requirements of S3.5.1(c) only apply to a part of an armrest (i.e., the portion of the armrest within the pelvic impact area).; B) See answer to A. C) The agency does not give prior approval to specific designs. I appears, however, that your design would not comply, since apparently the armrest will not deflect or collapse to within 1.25 inches of a rigid test panel surface without permitting contact with any rigid material, in this case the power window switch. In addition, the power window switch apparently does not have a minimum vertical height of not less than one inch. It is difficult to provide you with a definitive answer since section A-A of your drawing appears to be drawn to a different scale than the scale shown in the lower left corner of your drawing.; D) It appears from your drawing that even if the requirements o S3.5.1(b) were amended, as you suggested, to limit their application to the pelvic impact area of the armrest, the design would not comply since the power window switch area of the armrest is within the pelvic impact area. Rather than seeking an amendment to the standard, you may want to consider modifying your design so that it will comply with either 3.5.1(a) or (c) of the standard.; If you have any further questions, please let me know. Sincerely, Frank Berndt, 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.