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: aiam2596OpenMr. Eric E. Gough, Staff Assistant (Technical), Lucas Industries North America, Inc., Two Northfield Plaza, Troy, MI 48084; Mr. Eric E. Gough Staff Assistant (Technical) Lucas Industries North America Inc. Two Northfield Plaza Troy MI 48084; Dear Mr. Gough: This is in reply to your letter of May 13, 1977, to the Administrato asking whether the circuitry diagram that you enclosed would allow compliance with S4.5.2 of Federal Motor Vehicle Safety Standard No. 108.; Paragraph S4.5.2 requires that 'each vehicle shall have a means fo indicating to the driver when the upper beams of the headlamps are on that conforms to SAE Recommended Practice J564a, April 1964 ....' Your diagram appears to meet the specifications of J564a allowing compliance of the system with S4.5.2 when installed in a motor vehicle. The entity legally responsible for compliance with S4.5.2, of course, is the vehicle manufacturer who must certify that its products meet all applicable Federal motor vehicle safety standards.; Yours truly, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam5253OpenMr. Milford R. Bennett, Head Safety Affairs and Operations NAO Engineering Safety Center General Motors Corporation 30200 Mound Road/S3-N27 Warren, MI 48090-9010; Mr. Milford R. Bennett Head Safety Affairs and Operations NAO Engineering Safety Center General Motors Corporation 30200 Mound Road/S3-N27 Warren MI 48090-9010; "Dear Mr. Bennett: This is in reply to your letter of October 7, 1993 to Howard Smolkin concerning information labels for vehicles covered by NHTSA temporary exemptions (49 CFR Part 555). Paragraph 555.9(b) requires that a windshield or side window label containing an advisory statement be affixed securely to each exempted vehicle. You have concluded that this label is intended to notify prospective purchasers that the vehicle has been exempted from compliance with certain Federal motor vehicle safety standards. Because General Motors (GM) does not intend to sell its recently exempted GMEV, it believes that it is not required to place the label on its vehicles. Section 123(b) of the National Traffic and Motor Vehicle Safety Act (the Act) (15 U.S.C. 1410(b)) specifies that ' t he Secretary may require that written notification of an exemption be delivered to the dealer and first purchaser for purposes other than the resale of such exempted motor vehicle in such manner as he deems appropriate.' NHTSA chose to exercise this discretionary power through promulgating paragraph 555.9(b) requiring windshield and side window labels on exempted vehicles, commenting that ' t he window label appears to be the most appropriate way of providing written notification of exemptions to dealers and first purchasers' (37 FR 25534). We read in The New York Times on October 14, 1993, that GM will build 50 Impacts (presumably the exempted GMEVs) 'and lend them for two to four weeks to 1,000 drivers around the country over the next two years, with the help of 14 utilities.' If these cars are made available through GM's dealer network, then we believe that the label should nevertheless be provided even if the vehicle is not sold, and that it should remain affixed until the vehicle is first lent or leased through the dealer. Although subsequent users of the GMEV will not have access to the temporary label in order to evaluate the risk they assume by accepting temporary use of a nonconforming motor vehicle, the permanently affixed exemption certification label will furnish this information should they care to consult it. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam0051OpenMr. O. Weinreich, Staff Engineer, Bayerische Motoren Werke, c/o Hoffman Motors Corporation, 50 Louis Street, South Hackensack, NJ 07606; Mr. O. Weinreich Staff Engineer Bayerische Motoren Werke c/o Hoffman Motors Corporation 50 Louis Street South Hackensack NJ 07606; Dear Mr. Weinreich: Thank you for your letter of February 21, 1968, to Mr. J. E. Leysath o this Bureau, concerning the use of tubular type bulbs in license plate lamps.; Motor Vehicle Safety Standard No. 108 requires that license plate lamp conform to Society of Automotive Engineers (SAE) Standard J587b. SAE J587b in turn requires that bulbs and bulb sockets conform to SAE Standards J573b and J567b, respectively. Since tubular type bulbs and sockets for these bulbs do not conform to these SAE Standards, their use in license plate lamps would not be permitted under the requirements of Standard No. 108.; Thank you for writing. Sincerely, David A. Fay, Office of Standards on Accident Avoidance Motor Vehicle Safety Performance Service; |
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ID: aiam4012OpenMr. W.S. Deason, Development Manager, IMI Norgren Enots Ltd., Enots Works, P.O. Box 22, Eastern Avenue, Lichfield, Staffordshire WS 13 6SB, ENGLAND; Mr. W.S. Deason Development Manager IMI Norgren Enots Ltd. Enots Works P.O. Box 22 Eastern Avenue Lichfield Staffordshire WS 13 6SB ENGLAND; Dear Mr. Deason: This responds to your June 14, 1985 letter to the National Highwa Traffic Safety Administration (NHTSA), Office of Vehicle Safety Standards, regarding Federal Motor Vehicle Safety Standard No. 106, *Brake Hoses*. Your letter has been referred to my office for reply.; You asked about 'DOT Certification' of your air brake hose and fittin assemblies. Our agency does not certify or approve in advance motor vehicles or motor vehicle equipment. Instead, under the National Traffic and Motor Vehicle Safety Act of 1966 (copy enclosed), each manufacturer of motor vehicles or motor vehicle equipment is responsible for certifying that its products meet all applicable safety standards. This 'self-certification' process requires each manufacturer to determine in the exercise of due care that its products meet all applicable requirements. This determination can be made by product testing. The tests in Standard No. 106 are performance requirements that your products must meet when tested by the agency for compliance.; The data forming the basis for your certification is retained by you and does not have to be submitted to NHTSA for approval. Our agency investigates safety-related defects and noncompliances with safety standards in motor vehicles and items of motor vehicle equipment. If a question should arise as to the compliance of your product with NHTSA requirements, you will be requested to produce records to show how you determined compliance. If you or the agency determines that a safety-related defect or noncompliance exists, you are obligated to notify purchasers of your product and remedy the problem without charge.; Paragraph S4 of Standard No. 106 defines 'brake hose' as: >>>a flexible conduit, other than a vacuum tubing connector manufactured for use in a brake system to transmit or contain the fluid pressure or vacuum used to apply force to a vehicle's brakes.<<<; We wish to emphasize that the definition of 'brake hose' include flexible conduits manufactured out of nylon tubing that transmit or contain the pressure or vacuum used to apply force to a vehicle's brakes. To be sold in the United States, your brake hose assemblies consisting of nylon tubing and 'push-in' type tube fittings must be certified as meeting all applicable requirements of Standard No. 106.; Under Standard No. 106, certification is accomplished when you mark on component of each of your reusable fittings with the 'DOT' symbol, pursuant to paragraph S7.2.2. The DOT symbol is your representation that your products were manufactured in compliance with applicable Federal motor vehicle safety standards. You are also required by the standard to mark your products with a designation, identifying you as the manufacturer, that is filed in writing with the Office of Vehicle Safety Standards. The designation is intended to identify the manufacturer or assembler of brake hoses in the event of a safety-related defect or noncompliance necessitated recall.; You asked whether there are standard forms for manufacturers t register their designation. The answer is no. Standard No. 106 describes the procedures for designation registration. NHTSA will accept any designation consisting of letters, numerals, or a symbol, or a combination of these. If your chosen designation has not been selected previously by another manufacturer, it is accepted and recorded by NHTSA.; I am enclosing copies of two procedural rules which apply to al manufacturers subject to the regulations of this agency. The first is 49 CFR Part 566, *Manufacturer Identification*. This rule requires your company to submit your name, address, and a brief description of the items of equipment you manufacture to the agency within 30 days after you import your products into the United States.; The other rule is 49 CFR Part 551, *Procedural Rules*. Subpart D o this regulation requires all manufacturers headquartered outside of the United States to designate a permanent resident of the United States as the manufacturer's agent for service of all process, notices, orders and decisions. This designation should be mailed to the Chief Counsel, National Highway Traffic Safety Administration, 400 Seventh Street, S.W., Washington, D.C. 20590, and must include the following information:; 1. A certification that the designation of agent is valid in form an binding on the manufacturer under the laws, corporate by-laws, or other requirements governing the making of the designation at the time and place where it is made,; 2. The full legal name, principal place of business and mailing addres of the manufacturer,; 3. Marks, trade names, or other designations of origin of any of th manufacturer's products which do not bear its name,; 4. A statement that the designation shall remain in effect unti withdrawn or replaced by the manufacturer,; 5. A declaration of acceptance duly signed by the agent appointed which may be an individual, a firm or a U.S. corporation, and; 6. The full legal name and address of the designated agent. In addition, the designation must be signed by a person with authorit to appoint the agent. The signer's name and title should be clearly indicated beneath his or her signature.; In addition to the copies of the materials described above, I have als enclosed a copy of Standard No. 106 with amendments to the standard. You will also find an information sheet describing Federal statutes and regulations affecting manufacturers of motor vehicle equipment, and information on how you can obtain copies of NHTSA's standards and regulations.; I hope this information is of assistance to you. Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam1210OpenMr. A. R. Woodroof, Assistant Attorney General, Supreme Court Building, 1101 East Broad Street, Richmond, VA 23219; Mr. A. R. Woodroof Assistant Attorney General Supreme Court Building 1101 East Broad Street Richmond VA 23219; Dear Mr. Woodroof: This is in response to your letter of July 31, 1973, concerning th effect of our Standard 208 on State laws requiring vehicles to be equipped with sear belts.; Section 103(d) of the National Traffic and Motor Vehicle Safety Act, 1 U.S.C. 1392(d), reads:; >>>Whenever a Federal motor vehicle safety standard established unde this title is in effect, no State or political subdivision of a State shall have any authority either to establish, or to continue in effect, with respect to any motor vehicle or item of motor vehicle equipment any safety standard applicable to the same aspect of performance of such vehicles or item of equipment which is not identical to the Federal standard. . . .<<<; Standard 208 (49 CFR 571.208) permits passenger cars to be manufacture under any one of several options for occupant crash protection. One of these options is 'complete passive protection', under which the vehicle must undergo a series of rigorous crash tests in which instrumented dummies without belt restraints show force levels that would not create serious injury to a human occupant in most cases. Manufacturers are not required by the standard to have seat belts at any position that meets the requirements of this option.; The NHTSA considers that Section 103(d), quoted above, clearly render void any State laws or regulations to the extent that they would require a vehicle to be equipped with seat belts at seating positions that comply with the complete passive protection option. Any State requirements that are not 'identical' to those of an applicable standard are preempted by that section, under basic Constitutional principles of the supremacy of Federal law.; I am enclosing some information on the efficacy of air cushio restraints, as you requested. We are pleased to be of assistance.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam4442OpenThe Honorable Harris W. Fawell House of Representatives Washington DC 20515; The Honorable Harris W. Fawell House of Representatives Washington DC 20515; "Dear Mr. Fawell: I have been asked to respond to your recent lette asking the Department of Transportation to provide you with information concerning the use of safety belts on school buses. You ask for this information on behalf of your constituent, Mr. Wayne Mann, in the Illinois Palos Community Consolidated Schools. Mr. Mann specifically seeks 'factual information relative to seat (lap) belts on school buses,' and information on funding for traffic safety programs involving hazardous conditions outside the school bus. I would like to begin with some background information on our school bus regulations. The National Highway Traffic Safety Administration (NHTSA) is responsible for developing safety standards applicable to all new motor vehicles, including school buses. In 1977, we issued a set of motor vehicle safety standards regulating various aspects of school bus performance. Among those standards is Standard 222, School Bus Passenger Seating and Crash Protection. Standard 222 requires large school buses (those with a gross vehicle weight rating over 10,000 pounds) to have passenger crash protection through a concept called 'compartmentalization.' Compartmentalization requires large school buses to incorporate certain protective elements into the vehicles' interior construction, thereby reducing the risk of injury to school bus passengers without the need for safety belts. These elements include high seats with heavily padded backs and improved seat spacing and performance. (Our regulations require a safety belt for the school bus driver because the driver's position is not compartmentalized. Further, because small school buses experience greater force levels in a crash, passengers on these vehicles need the added safety benefits of the belts.) School buses continue to have one of the lowest fatality rates for any class of motor vehicle. Large school buses are among the safest motor vehicles because of their size and weight (which generally reduce an occupant's exposure to injury-threatening crash forces), the drivers' training and experience, and the extra care other motorists take when they are near a school bus. For these reasons, NHTSA has not required safety belts in large school buses. I enclose a copy of a June 1985 NHTSA publication titled 'Safety Belts in School Buses,' which discusses many of the issues relative to this subject. I think your constituent may find this information helpful. With respect to hazardous conditions outside the school bus, the agency realizes that there are special problems of driver visibility associated with transporting students. NHTSA has addressed these problems in Federal Motor Vehicle Safety Standard 111, Rearview mirrors, paragraph S9. In 1975, NHTSA established special mirror requirements for school buses 'to reduce the danger of death or injury to school children (by giving) the school bus driver the fullest possible view of all sides of the vehicle...' (The proposed rule, including this preamble quotation, appears at 40 FR 33828, 33829, August 12, 1975. The final rule was published originally at 41 FR 36023, August 26, 1976.) One of these special requirements is that manufacturers equip a school bus with a crossview mirror that permits the driver to see the area in front of the bus. These special school bus mirror requirements help contribute to the low number of fatalities associated with school bus travel. Your constituent also mentions funding to implement a program to address hazardous conditions outside the school bus. The agency believes that its school bus regulations effectively address the safety of school bus design and performance, and contribute to occupant safety. We note, however, that /402 of the Highway Safety Act, provides funds to each State for its use in conducting a highway safety program. Some of these funds are distributed by the State to local governments or organizations within the State. To get information on Illinois' /402 funds, I suggest that your constituent contact the Illinois Governor's Representative for Highway Safety, Mr. Melvin H. Smith, Director, Division of Traffic Safety, 319 Administration Bldg., 2300 South Dirksen Pkwy., Springfield, IL 62764. If you or Mr. Mann have further questions, I encourage you to contact our agency. Sincerely, Erika Z. Jones Chief Counsel Enclosure"; |
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ID: aiam3387OpenMr. Kenneth C. Lenz, Jr., Hendrickson Mfg. Co., Mobile Equipment Division, 8001 West 47th Street, Lyons, IL 60534; Mr. Kenneth C. Lenz Jr. Hendrickson Mfg. Co. Mobile Equipment Division 8001 West 47th Street Lyons IL 60534; Dear Mr. Lenz: This responds to your November 25, 1980, letter asking whether an safety standards have been violated by a truck modification that you perform. In your modification, you alter a chassis to provide right-hand controls. The vehicle is then sent to a final-stage manufacturer for completion.; As an incomplete vehicle manufacturer, you are required to attach th appropriate label to the vehicle in accordance with Part 567, *Certification*. That label makes certain statements about the compliance of the vehicle with safety standards as a result of your modifications.; You ask whether any safety standards have been violated by you modifications. It is impossible for the agency to determine compliance without testing one of your vehicles. You list several changes that you make to the vehicle, including the addition of: a foot throttle, foot service brake, hand spring brake, turn signal, transmission selector, and steering wheel. The agency has safety standards that govern many of these devices. These standards are found in Volume 49 of the Code of Federal Regulations, in Part 571. It is a manufacturer's responsibility to ensure that its vehicles comply with these standards. The only advice that we can offer is that nothing precludes the type of modifications that you propose. The installation of right-hand controls is permissible as long as the compliance with all safety standards is maintained.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0952OpenMr. Richard H. Hardesty, III, Marketing Specialist-Lighting, Plastics Department, E. I. Dupont De Nemours & Company, Wilmington, DE, 19898; Mr. Richard H. Hardesty III Marketing Specialist-Lighting Plastics Department E. I. Dupont De Nemours & Company Wilmington DE 19898; Dear Mr. Hardesty: This is in reply to your letter of October 11, 1972, concerning th application of Motor Vehicle Safety Standard No. 302, 'Flammability of Interior Materials'. You ask whether the following components are subject to the requirements of the standard: horn buttons, decorative medallions, control knobs and handles, instrument dials and faces, break resistant mirrors, and lighting fixture lenses or diffusers.; The components that must meet the requirements of the standard ar listed in Paragraph S4.1. None of the components you have asked about are specifically listed in Paragraph S4.1, and normally will not be subject to the requirements. However, components may nevertheless be covered to the extent that they contain materials 'that are designed to absorb energy on contact by occupants in the event of a crash,' or to the extent that they form part of a component listed under Paragraph S4.1. For example, we might consider a decorative medallion that forms part of the surface of a front or side panel to be incorporated into the panel and therefore subject to the standard.; In answer to your request for 'the text of the proposed amendment...i preparation which will establish numerical size...and some information on when it will be incorporated into MVSS- 302.' I have no public information on this subject at this time.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1640OpenMr. Jack M. Dubard, Dubard & Vail, P.O. Box 38, Bonneville, MS 38829; Mr. Jack M. Dubard Dubard & Vail P.O. Box 38 Bonneville MS 38829; Dear Mr. Dubard: This responds to your October 11, 1974, letter (JAH:nh) asking whethe a truck body manufactured in part before and in part after the effective date of Standard No. 121, *Air brake systems*, must conform to the requirements of that standard. Standard No. 121 becomes effective for trailers on January 1, 1975, and for trucks and buses on March 1, 1975.; Standard No. 121 applies to air brake-equipped trucks, buses, an trailers, but not to truck bodies, which we consider to be items of motor vehicle equipment. Therefore, if your client only makes and sells truck bodies, his products are not subject to Standard No. 121.; If your client combines a chassis-cab with a truck body, he may in man cases be manufacturing a new motor vehicle, and as such, be responsible for compliance with Federal motor vehicle safety standards. I have enclosed 49 CFR Parts 567, *Certification*, and 568, *Vehicles manufactured in two or more stages*, which set out the certification responsibilities of persons who manufacture vehicles in stages.; Section 568.8 states that a 'final-stage manufacturer' (frequently thi will be one who installs a truck body on a chassis cab) must certify the vehicle as conforming with all standards effective as of the date of manufacture of the 'incomplete vehicle,' the date of final completion, or any date between those two dates. The manufacturer makes this certification based both on documentation furnished by the incomplete vehicle manufacturer under S 568.4, and on the changes he has made to complete the vehicle.; Therefore, if your client completes a truck by adding a truck body t it, he must certify that the vehicle meets all applicable standards as of a date chosen by him within the specified period. For example, a vehicle completed by the addition of a body on March 15, 1975, which used a chassis-cab manufactured on February 1, 1975, could be certified as complying with all standards as of February 1, 1975. In this case, the vehicle would not be subject to Standard No. 121.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam3368OpenMr. G. Montgomery Spindler, Uniroyal, Inc., 1700 K Street, N.W., Washington, DC 20006; Mr. G. Montgomery Spindler Uniroyal Inc. 1700 K Street N.W. Washington DC 20006; Dear Mr. Spindler: This is in response to your letter of October 10, 1980, requestin clarification of the explanation of Treadwear grading in Figure 2 of the Uniform Tire Quality Grading (UTQG) Standards (49 CFR S 575.104). You ask whether the explanation can be interpreted to mean that the relative treadwear performance of different tires on the UTQG test course in San Angelo, Texas will be consistent with the relative performance of the tires when driven under comparable conditions on other roads.; In experimental testing leading to promulgation of the UTQG regulation the National Highway Traffic Safety Administration (NHTSA) tested the treadwear of various tire lines not only on the San Angelo course but on roads in other parts of the country. The agency concluded that the UTQG grades established for different tires in testing on the San Angelo course accurately represent the relative performance of the tires obtainable on roads elsewhere in the United States, assuming that the tires to be compared are run under identical conditions.; The statement in Figure 2 of the UTQG regulation that a tire graded 15 would wear one and one-half times as well on the government course as a tire graded 100 was not intended to suggest that the tire would not wear one and one-half times as well on another course, if conditions of use were controlled. The term 'relative performance' in Figure 2 refers to the performance of tires in comparison to other tires, and the term 'norm' refers to the consistently obtainable relative performance of tires when tested under controlled conditions. Thus, the explanation indicates that, although the relative performance of different tires will be consistent when the tires are tested under controlled conditions, this relative performance may not be obtainable in actual use, if one tire is subjected to more severe road or weather conditions, abusive driving or improper maintenance.; NHTSA will provide confidential treatment for your October 10, 1980 letter.; Sincerely, Frank Berndt, Chief Counsel |
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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.