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
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ID: aiam4972OpenD. E. Dawkins, Acting Director Automotive Safety Planning and Compliance Product Strategy and Regulatory Affairs Office Chrysler Corporation CIMS 414-01-22 12000 Chrysler Drive Highland Park, MI 48288-0857; D. E. Dawkins Acting Director Automotive Safety Planning and Compliance Product Strategy and Regulatory Affairs Office Chrysler Corporation CIMS 414-01-22 12000 Chrysler Drive Highland Park MI 48288-0857; "Dear Mr. Dawkins: This responds to the petition dated September 30 1991, that Mr. Kittle submitted on behalf of Chrysler Corporation seeking temporary exemption for the TEVan from several Federal motor vehicle safety standards on the basis that the exemption would facilitate the development and field evaluation of low emission motor vehicles. The petition indicates (page 4) that exemption is sought for four l989 Dodge Caravans, converted to electric power, that 'were manufactured for test and evaluation'. We understand that this conversion occurred after completion of the manufacture of the vans, and that the conversion was performed by a subsidiary of Chrysler. If an exemption is granted, the petition states that 'one or more of the vehicles will be titled and sold for ongoing endurance evaluation.' Finally, we understand that the TEvans are currently in the possession of the Electric Power Research Institute in California for evaluation, and that presumably they are being driven on the public roads. We regret the delay in responding to Mr. Kittle's letter. The petition represents a rare instance in which a manufacturer has petitioned for an exemption for a vehicle whose manufacture has been completed, and which has been in use. The purpose of an exemption is to allow a manufacturer to engage in conduct that would otherwise be prohibited by the National Traffic and Motor Vehicle Safety Act, specifically, the manufacture for sale, sale, offer for sale, or introduction or delivery for introduction, or importation into the United States of a motor vehicle that does not conform to all applicable Federal motor vehicle safety standards, and which does not bear a certification of compliance with those standards. With respect to the four TEVans for which petition has been made, it appears that they have already been introduced into interstate commerce without a certification of compliance (or, if bearing the certification of the original vehicle, a certification that is false and misleading in a material respect, a further violation of the Act). Any exemption by the Administrator could not cover conduct violative of the Act that has already occurred. However, we have concluded that the Administrator may grant an exemption to vehicles, which would apply to conduct that would violate the Act, but which has not occurred. As Chrysler seeks an exemption in order to sell the TEVans, or to offer them for sale, the Administrator's exemption authority may be exercised to permit Chrysler to do so, after the procedural requirements have been followed. The petition meets our requirements for form and content, and a notice requesting public comment is being prepared for publication in the Federal Register. We shall notify you when the Administrator has reached a decision. If you have any questions, you may discuss them with Taylor Vinson of this Office (202-366-5263). Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam5660OpenErika Z. Jones, Esq. Mayer, Brown & Platt 2000 Pennsylvania Ave. NW Washington, DC 20006-1882; Erika Z. Jones Esq. Mayer Brown & Platt 2000 Pennsylvania Ave. NW Washington DC 20006-1882; Dear Ms. Jones: This responds to your letter of November 27, 199 concerning the requirement in S4.4 of Standard No. 207, Seating Systems. That section provides that: Seats not designated for occupancy while the vehicle is in motion shall be conspicuously labeled to that effect. You requested confirmation that this requirement would not apply to a seat that was equipped with a folding seat back to convert the seat to a bed. You are correct. NHTSA interprets this requirement as applying only to positions that do not qualify as designated seating positions under 49 CFR 571.3. Therefore, 'designated seating positions' that convert to a non-seating use do not have to comply with the labeling requirement of S4.4. I hope this information has been helpful. If you have other questions or need some additional information, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely, Samuel J. Dubbin Chief Counsel; |
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ID: aiam0198OpenMr. Yoshio Horii, Manager, Lighting Engineering Department, Ichikoh Industries, Ltd., 5-10-18, Higashi-Gotanda, Shinagawa-Ku, Tokyo 141, Japan; Mr. Yoshio Horii Manager Lighting Engineering Department Ichikoh Industries Ltd. 5-10-18 Higashi-Gotanda Shinagawa-Ku Tokyo 141 Japan; Dear Mr. Horii: Thank you for your letter of December 16, 1969, concerning th relationship between performance requirements of Standard No. 108 and the referenced and subreferenced SAE standards in Standard No. 108.; Public Law 89- 563 requires that the motor vehicle safety standards b stated in terms of what is to be accomplished rather than in terms of specific designs, and that they be objective, reasonable, practicable, and meet the need for motor vehicle safety. In addition, the law required that the initial safety standards be based on *existing* standards.; Initial Federal Motor Vehicle Safety Standard No. 108 was based on th *existing* SAE standards as specified in Tables I and III of Standard No. 108. In some instances, these specified SAE standards in turn subreference other SAE standards that are design oriented, particularly the subreferenced standards on bulbs, bulb sockets and sealed beam headlamp units.; As provided by an interpretation (copy enclosed) issued on August 12 1968, entitled, 'Bulbs and Bulb Sockets,' bulbs conforming to Table I of subreferenced SAE J573 and bulb sockets conforming to subreferenced SAE J567 *need not* be used in lamp assemblies meeting the requirements of Standard No. 108. Therefore, as an example, tail lamps need meet only the requirements of SAE J585c (including color test in accordance with SAE J578a) when tested in accordance with the specified Sections of subreferenced SAE J575c.; The above interpretation does not apply to sealed beam headlamps Paragraph S3.1.1 and Tables I and III of Standard No. 108 specify that headlamps shall be designed to conform to SAE J579a and J580a. These specified standards in turn subreference SAE J573b and J571b. The dimensional requirements of SAE J571b serve a need for safety in that replacement sealed beam units are readily available, and standardization of inspection equipment and procedures is possible.; In summary, the referenced and subreferenced SAE standards ar applicable except as specifically provided by the enclosed interpretation.; With reference to the last paragraph in your letter, it is recognize that a manufacturer of motor vehicles may, as part of his contractual relationship with a supplier, require that the supplier certify conformance of the items provided by the supplier. Currently Public Law 89-563 does not require Ichikoh to certify conformance to Standard No. 108 of the lighting equipment it provides. However, an amendment to the standard has been proposed which would make the standard directly applicable to certain items of lighting equipment. This proposal would require Ichikoh to certify conformance, but only if Ichokoh (sic) were shipping such items directly to distributors and dealers in the United States. I enclose a copy of this proposal for your information.; Sincerely, Charles A. Baker, Office of Standards on Accident Avoidance Motor Vehicle Safety Performance Service; |
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ID: aiam1744OpenMr. J. W. Kennebeck, Manager, Emissions, Safety & Development Dept., Volkswagen of America, Inc., Englewood Cliffs, NJ 07632; Mr. J. W. Kennebeck Manager Emissions Safety & Development Dept. Volkswagen of America Inc. Englewood Cliffs NJ 07632; Dear Mr. Kennebeck: This responds to Volkswagen's December 11, 1974, request fo confirmation that the deletion of the ignition interlock requirement from Standard No. 208, *Occupant crash protection*, does not have the effect of prohibiting installation of an interlock device in a vehicle which meets the requirements of S4.1.2.; Volkswagen will utilize a passive belt system in satisfaction of th requirements of S4.1.2. Passive belts are subject to specific belt assembly requirements of S4.5.3.3. These requirements were recently modified by deletion of the requirement for a belt interlock system (39 FR 38380, October 31, 1974), and passive belt assemblies must now conform to S7.1 (Adjustment), S7.2 (Latch mechanism), and S7.3 (Seat belt warning system).; Your interpretation of these requirements is correct. The Federal moto vehicle safety standards are minimum performance requirements with which each vehicle to which they are applicable must comply. They do not, however, prohibit installation of additional safety devices. As a practical matter, of course, additional devices could not be installed if that installation had the effect of causing the required systems not to comply.; The NHTSA agrees than (sic) an interlock system is important fo ensuring use of a passive belt system.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam3779OpenMr. Vincent L. Lobascio, Senior Investigator, Motor Carriers, State of New Jersey, Department of Transportation, Motor Carrier Inspection, Box 10009, Newark, NJ 07101; Mr. Vincent L. Lobascio Senior Investigator Motor Carriers State of New Jersey Department of Transportation Motor Carrier Inspection Box 10009 Newark NJ 07101; Dear Mr. Lobascio: This responds to your letter to Mr. Kratzke of my staff, in which yo questioned a prior interpretation of Safety Standard No. 217, *Bus Window Retention and Release* (49 CFR S 571.217). You noted that you disagree with an August 18, 1983 interpretation addressed to Champion Home Builders, which stated that doors may be considered as emergency exits for the purposes of section S5.2.1, provided that those doors meet the requirements applicable to emergency exits. I have enclosed a copy of this interpretation for your information.; You stated in your letter that you agree that doors may be counted a emergency exits, but only if the requirements of S5.2.1.1 are met. In other words, the only time doors can be counted as emergency exits in your opinion is when a bus has at least one side door for every three designated seating positions. That statement reflects an incorrect interpretation of the requirements of section S5.2.; Section S5.2 of Standard No. 217 sets forth requirements for th provision of emergency exits in buses. Section S5.2.1 contains the requirements applicable to buses with a gross vehicle weight rating in excess of 10,000 pounds. This is the group of vehicles your letter addresses. Section S5.2.1 requires that all buses provide side exits *and* at least one rear exit (a roof exit may be substituted for the rear exit). S5.2.1 places no limit on the types of openings that may be used as exits. As noted in my August 18 interpretation, the agency has never stated that doors could not be counted as side exits, provided that they met all other requirements applicable to emergency exits. Section S5.2.1.1 allows, as an alternative to complying with the requirements for side exits and a rear exit, the exclusive use of side doors as emergency exits. Under section S5.2.1.1, buses may be equipped with one side door for every three designated seating positions. This section in no way limits the availability of side doors as side exits under section S5.2.1, it merely adds a special case for buses not equipped with a rear exit or roof exit.; You went on to state your opinion that a particular manufacturer's bu does not comply with the requirements of section S5.2, because the door designated as an emergency exit does not satisfy the requirements applicable to emergency exits. I am sure that you understand it is impossible for this agency to determine, based on photographs and a description of the bus, whether a bus certified as complying with those requirements in fact does not comply. Our enforcement personnel will specifically check one of these buses to ensure that they do comply with Standard No. 217.; I thank you for your efforts to ensure the safety of bus passengers and hope that you will contact us again if you believe that some model of bus fails to comply with the requirements of a Federal standard. The cooperation of State officials is essential to this agency's efforts to improve safety on the public roads.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0856OpenProfessor Ralph W. Zimmer, Assistant Professor, Department of Civil Engineering & Engineering Mechanics, Montana State University, Bozeman, MT 59715; Professor Ralph W. Zimmer Assistant Professor Department of Civil Engineering & Engineering Mechanics Montana State University Bozeman MT 59715; Dear Professor Zimmer: Thank you for your letter of September 6, 1972, and the suggestions fo improving motor vehicle safety.; The National Highway Traffic Safety Administration is aware of the hor problem described in your letter and recognizes that a driver's inability to quickly locate it can result in accidents, especially during panic situations. We have not issued any standard specifying the location of horn rim buttons or rings at this time, but we have initiated research to determine the best location and type of horn switches. Data from this research will be used for possible future rulemaking action.; We are preparing to issue in the near future a notice of propose rulemaking to amend Federal Motor Vehicle Safety Standard No. 108 'Lamps, Reflective Devices and Associated Equipment'. This notice will propose that stop lamps be separate from other rear lamps, and, if the proposal is adopted, simultaneous operation of the stop and hazard warning signals will then be possible.; The four-wheel drive recreational vehicle described in your letter i classified under the Federal motor vehicle safety standard as a multipurpose passenger vehicle, and some of our present safety standards are not applicable to it. We are however monitoring the type and frequencies of all types of accidents and, if it appears the applicability of these standards should be extended to multipurpose passenger vehicles, we will propose such amendments. Enclosed for your review and further information is a summary description of all the safety standards and their applicability, revised as of June 1972.; Most of the late model cars now have a self-cancelling feature on thei turn signals which has eliminated most of the problems described in your letter. Standard No. 108 mandates self- cancelling turn signals on most motor vehicles manufactured on or after January 1, 1973. We have no immediate plans to issue requirements for audible alarms in vehicles, but we do appreciate your comments. If future safety conditions should warrant, we will consider issuing such requirements.; Again, thank you for writing to us and, if we can be of any furthe service to you, please let us know.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam4546OpenMr. Robert Daugherty Quality Assurance Manager Safety Rehab Systems, Inc. 147 Eady Court Elyria, OH 44035; Mr. Robert Daugherty Quality Assurance Manager Safety Rehab Systems Inc. 147 Eady Court Elyria OH 44035; "Dear Mr. Daugherty: This is a response to your letter of February 5 1988, in which you sought an interpretation of Standard 213, Child Restraint Systems (49 CFR 571.213). I regret the delay in this response. Specifically, your letter stated that your company manufactures wheelchairs for severely handicapped children. Your letter stated that your company believes that Standard 213 does not apply to 'durable medical products (wheelchairs, positioning systems)' and asked if this belief is correct. As explained below, your belief is not entirely correct. Section S3 of Standard No. 213 specifies that 'this standard applies to child restraint systems for use in motor vehicles and aircraft.' Section S4 of the standard defines a child restraint system as 'any device except Type I or Type II seat belts, designed for use in a motor vehicle or aircraft to restrain, seat, or position children who weigh 50 pounds or less.' No exception is made for restraints designed for use by physically handicapped children who weigh 50 pounds or less. Further, paragraph S6.1.2.1.1 of Standard No. 213 includes the following language: 'A child harness, booster seat with a top anchorage strap, or a restraint designed for use by physically handicapped children shall be installed at the center seating position of the standard seat assembly in accordance with the manufacturer's instructions provided with the system pursuant to S5.6.' This language makes clear that restraints designed for use by physically handicapped children are subject to the requirements of Standard No. 213. Under these criteria, wheelchairs, strollers, and so forth would not be 'child restraint systems' within the meaning of Standard No. 213 because these devices are designed to transport children outside of a motor vehicle or aircraft. Therefore, wheelchairs, strollers, and similar devices are not child restraint systems within the meaning of S3 of Standard No. 213. Such devices may be subject to regulation by the Food and Drug Administration, under its authority to regulate medical 'devices.' However, the devices described in your letter as 'positioning systems' are child restraint systems subject to the requirements of Standard No. 213. Your 'Safety Plus Model 501' includes a 'removable positioning unit' that is designed to restrain and position a child riding in a motor vehicle. Your '900 Series Transporter' is designed so that the rear wheels can be folded under to allow the device to be used to restrain and position a child riding in a motor vehicle. Therefore, these devices are 'child restraint systems' within the meaning of S3 of Standard No. 213, and must be certified as complying with the requirements of the standard. NHTSA has said in the past that, since it is possible to offer handicapped children the same level of crash protection afforded to all other children, there is no reason to permit handicapped children to be offered a lesser degree of safety protection in the event of a crash. (See the enclosed October 16, 1986 letter I sent to Mr. Terry Woodman on this subject.) You also asked if there are any standards applicable to 'tie-downs' used on school buses. These 'tie-downs' are straps designed to restrain wheelchairs and their occupants in a motor vehicle in the event of a crash. Since wheelchairs are not subject to Standard No. 213 or any other of this agency's regulations, as explained above, we have no standard applicable to 'tie-downs' or other devices used to position wheelchairs in motor vehicles. I explained this in detail in the enclosed July 31, 1987 letter to Mr. Richard Maher. I hope this information is helpful. If you have further questions or need more information on this subject, please feel free to contact Ms. Joan Tilghman of my staff at this address or by telephone at (202) 366-2992. Sincerely, Erika Z. Jones Chief Counsel Enclosures"; |
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ID: aiam3283OpenMr. D. J. Hitt, Vice President, Safety and Security Consultants, 702 Candy Mountain road, Birmingham, AL 35217; Mr. D. J. Hitt Vice President Safety and Security Consultants 702 Candy Mountain road Birmingham AL 35217; Dear Mr. Hitt: This is in reply to your letters of April 11, and April 25, 1980 respectively to this agency and to Mr. Vinson of this office, (sic) These letters reference requirements for side marker reflectors and clearance lamps for trailers used to carry agricultural products over the public roads.; You say that your trailers travel 'as much as several hundred miles o the highways at all hours of the day and night'. Therefore, they are 'motor vehicles' subject to all applicable Federal Motor Vehicle Safety Standards.; I enclose a copy of Federal Motor Vehicle Safety Standard No. 10 (Title 49, Code of Federal Regulations, section 571.108). You will see that marker lamps and reflectors are required on all trailers, while rear clearance lamps need be added only if the overall width of a trailer is 80 inches or more. A clearance lamp facing to the rear may be combined with a rear side marker lamp, we assume that is what you mean by a 'side clearance lamp' as the standard speaks only in terms of 'front' and 'rear' clearance lamps.; You have also asked for the 'early history' of why these lamps ar required pursuant to 'Regulation No. 393.15.' As a matter of clarification that section of Title 49 is enforced by a different agency, the Bureau of Motor Carrier Safety Federal Highway Administration, and covers lighting equipment required for commercial vehicles being used in interstate commerce. Our lighting standard, essentially identical, must be met before the vehicle is used, i.e., from time of manufacture until time of sale. To answer your question, clearance lamps must indicate the overall width of the trailer, in order that other drivers may be alerted to the presence on the road of a large vehicle. Side markers help identify the presence of a vehicle whose head lamps or taillamps may not be seen by a driver approaching it from a 90 degree angle, such as at an intersection.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2538OpenMr. R.A. Bynum, Supervisor, Pupil Transportation Service, Commonwealth of Virginia, State Department of Education, Richmond, Virginia 23216; Mr. R.A. Bynum Supervisor Pupil Transportation Service Commonwealth of Virginia State Department of Education Richmond Virginia 23216; Dear Mr. Bynum: This responds to your February 18, 1977, letter asking whether Standar No. 222, *School Bus Passenger Seating and Crash Protection*, permits the use of a two-passenger front-row seat with a corresponding two-passenger front-row restraining barrier. Secondly, you ask whether the State of Virginia can require the use in joints of discrete fasteners and welding, and not adhesives, without conflicting with the requirements of Standard No. 221, *School Bus Joint Strength*. Finally, you ask who must certify that a vehicle complies with Standard no. 105, *Hydraulic Brake Systems*.; The NHTSA has issued an interpretation allowing the use of two-passenger front-row seat with a two-passenger restraining barrier. This can be accomplished by the use of a two-passenger seat cushion and a three-passenger seat back as you suggest. I am enclosing a copy of the NHTSA interpretation for your information.; Regarding your second question concerning the use of adhesives in a bu body joints, the Federal bus body joint standard requires only that joints meet a specified strength requirement. The NHTSA does not require any particular type of joint construction. Therefore, the purchaser and manufacturer can decide upon any method of joint construction as long as the joint meets Federal strength specifications.; Your final question asks who must certify that a small school bu (under 10, 000 pounds_ is in compliance with Standard No.105, *Hydraulic Brake System*. To assign responsibility for the certification of multi-stage vehicles, NHTSA has issued Part 568, *Vehicles Manufactured in Two or More Stages* (enclosed). The manufacturer of an 'incomple- te-vehicle' (such as a cab-chassis) must provide documentation to the intermediate- and final-stage manufacturer of the vehicle on how to complete it so that it complies with all applicable standards. it is the responsibility of the final-stage manufacturer to affix a certification label unless the incomplete- or intermediate-stage manufacturer assumes this responsibility.; On a related matter concerning small school buses, it is ou understanding that school buses weighing under 10, 000 pounds will be available after April 1, 1977.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam0505OpenMr. Richard H. Miehe, Vice President, Engineering, Seats, Inc., 350 N. Dewey, Reedsburg, WI 53959; Mr. Richard H. Miehe Vice President Engineering Seats Inc. 350 N. Dewey Reedsburg WI 53959; Dear Mr. Miebe: This is in reply to your letter of October 4, 1971, in which you aske our opinion as to whether Standard No. 207 permits a suspension type truck seat with fore and aft adjustment to be equipped with seat belt type webbing from the seat to the floor. It is our position that such webbing may be used to provide the strength required by Standard No. 207 and that a seat so equipped must conform to S4.2(c) of the standard (unless, as seems unlikely, the occupant's seat belt is anchored to the floor and not to the seat). Instructions for the adjustment of the seat to floor webbing are essential to the safe operation of such a system, however, and should be provided.; I apologize for any inconvenience that our delayed response may hav caused you.; Sincerely, Richard B. Dyson, Assistant 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.