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: aiam4543OpenMr. Davis Thekkanath Sr. Supervising Engineer Oshkosh Truck Corporation P.O. Box 2566 2307 Oregon Street Oshkosh, WI 54903-2566; Mr. Davis Thekkanath Sr. Supervising Engineer Oshkosh Truck Corporation P.O. Box 2566 2307 Oregon Street Oshkosh WI 54903-2566; "Dear Mr. Thekkanath: This responds to your letter requesting a interpretation of Safety Standard No. l2l, Air Brake Systems. Section S5.l.l of the standard requires trucks and buses to have an air compressor of sufficient capacity to bring the pressure in the supply and service reservoirs from 85 psi to l00 psi within a specified time. You inquired about the meaning of this requirement in the context of a truck with a trailer behind it. You particularly asked whether the air compressor capacity requirement includes the volume of service reservoirs for the trailer. As discussed below, only the truck reservoirs need to be considered for this requirement. By way of background information, the National Highway Traffic Safety Administration does not provide approvals for motor vehicles or motor vehicle equipment. Under the National Traffic and Motor Vehicle Safety Act, it is the responsibility of the manufacturer to ensure that its vehicles and equipment meet applicable standards. The following represents our opinion based on the facts provided in your letter. Sections S5.l and S5.l.l of Standard No. l2l read as follows: S5.l Required equipment--trucks and buses. Each truck and bus shall have the following equipment: S5.l.l Air Compressor. An air compressor of sufficient capacity to increase air pressure in the supply and service reservoirs from 85 pounds per square inch (p.s.i.) to l00 p.s.i. when the engine is operating at the vehicle manufacturer's maximum recommended r.p.m. within a time, in seconds, determined by the quotient (Actual reservoir capacity x 25)/Required reservoir capacity. The reference in section S5.l.l to 'supply and service reservoirs' refers only to the supply and service reservoirs in the truck or bus subject to the requirement. Similarly, the term 'actual reservoir capacity' refers only to the actual reservoir capacity of that truck or bus, and the term 'required reservoir capacity' refers only to the reservoir capacity required for that truck or bus. Thus, for a truck designed to tow an air-braked trailer, only the truck's reservoirs need to be considered for this requirement. For purposes of testing, the towing vehicle protection system would be activated. While Standard No. l2l does not specify air compressor capacity for towing vehicles in terms which address towed vehicles, we assume that manufacturers of vehicles designed to tow air-braked vehicles will design them to have sufficient air compressor capacity to ensure safe braking performance under conditions of reasonably forseeable use, including when they are towing air-braked vehicles. Sincerely, Erika Z. Jones Chief Counsel"; |
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ID: aiam3286OpenMr. Tom Spencer, John Evans Mfg. Co., P.O. Box 669, Sumter, SC 29150; Mr. Tom Spencer John Evans Mfg. Co. P.O. Box 669 Sumter SC 29150; Dear Mr. Spencer: This responds to your May 6, 1980, telephone conversation with Roge Tilton of my staff in which you asked about the certification responsibilities for an incomplete trailer manufacturer. You indicated in your conversation that you manufacture chassis for trailers and supply them to final- stage manufacturers who complete them by the addition of a body. In particular, you asked whether you are required to comply with the provisions of Part 568.4, *Vehicles Manufactured in Two or More Stages*.; Part 568 places certain certification responsibilities upon incomplet vehicle manufacturers. The term 'incomplete vehicle' is defined in section 568.3, as an assemblage including, at a minimum, the frame, chassis structure, power train, steering system, suspension and braking system to the extent that these systems are to be part of the completed vehicle. If a chassis that you manufacture is completed to the extent that it has the above-listed components and merely needs the addition of a body by a final-stage manufacturer, it would be considered an incomplete vehicle and would be required to comply with the incomplete vehicle document requirements of Part 568. Please note that your incomplete trailer need not have all of the components listed above to be considered an incomplete vehicle subject to Part 558 (sic). It need only have those components in the list that will be found in the completed vehicle. Since your trailer is an incomplete vehicle but not a chassis-cab as that term is defined in Part 567, *Certification*, it would not be required to have a chassis-cab manufacturer's certification label attached to it.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0853OpenMr. W.G. Milby, Project Engineer, Blue Bird Body Company, Fort Valley GA 31030; Mr. W.G. Milby Project Engineer Blue Bird Body Company Fort Valley GA 31030; Dear Mr. Milby: This is in reply to your letter of August 24, 1972, requesting a opinion as to appropriate steps to take in certifying vehicles you complete when the chassis, as delivered to you, are equipped with tires which are inadequate for the loads the vehicles are intended to carry. You state you are presently certifying the vehicles on the basis of the load ratings of correct tires, arranging for these tires to be installed by the dealer, and requesting a notarized statement from him to that effect. As a basis for this procedure, you refer to our previous correspondence to you dated March 24, 1972, in which we authorized a somewhat similar procedure involving certain school buses.; As stated to you in our letter of March 24, the procedure outline therein 'is allowed only as to chassis that have already been received by Blue Bird as of the receipt of this letter . . .' Blue Bird is the final-stage manufacturer, and is responsible for the weight ratings applied to the vehicles presently in question. These ratings must be consistent with the definitions of those terms in the regulations, and must reflect the characteristics of the vehicles at the time of their sale to the consumer, assuming further manufacturing does not occur. Although you receive assurances from a dealer that he will change the tires, this will not absolve you from responsibility under the regulations should the dealer fail to do so. We are of the opinion that the best procedure for Blue Bird to follow is to replace the tires before delivery to the dealer.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1741OpenMs. Anita L. Mead, Secretary, Mead's East Side Wheel & Frame Co., P.O. Box 1367, Garden City, KS 67846; Ms. Anita L. Mead Secretary Mead's East Side Wheel & Frame Co. P.O. Box 1367 Garden City KS 67846; Dear Ms. Mead: This is in reply to your letter of December 6, 1974, asking whether yo must certify or recertify vehicles when you install new tag axles or extend truck frames, thereby changing the truck's gross vehicle weight rating.; NHTSA Certification regulations apply to manufacturers and alterers o new vehicles. A new vehicle is a vehicle which has not yet been sold to a user. If you perform these particular operations on new vehicles before they are 'completed' (49 CFR S568.3) and certified, and they are completed by you, then you will be responsible for certification. If you perform these operations on a new vehicle that has been completed and previously certified, then you will in all likelihood be a vehicle alterer, and subject to specific requirements applicable to alterers.; I have enclosed a copy of NHTSA's Certification regulations (49 CFR S 567,568) which contain the requirements for certification by manufacturers and alterers. Also enclosed is information on where you may obtain copies of other NHTSA standards and regulations. If you have further questions regarding these materials, please write to me.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam4810OpenMr. Paul G. Scully Vice President Peterson Manufacturing Company 4200 East 135th Street Grandview, MO 64030; Mr. Paul G. Scully Vice President Peterson Manufacturing Company 4200 East 135th Street Grandview MO 64030; "Dear Mr. Scully: This is in reply to your letter of August l4, l99 (postmarked September l9), asking that we notify the police department of Tuscon, Arizona, that reflex reflectors are not required to have SAE markings 'in order to be perfectly legal reflectors.' You also state that another agency of the Department of Transportation, the Federal Highway Administration's Office of Motor Carrier Safety, 'still retain(s) these marking requirements in their publication' and appeal for 'a uniform set of regulations between the two government agencies involved.' Because this matter has not been brought to our attention by the police department of Tuscon, we are responding directly to you so that you may furnish copies to whomever you deem it most advisable. We confirm your understanding that 49 CFR 571.108, Federal Motor Vehicle Safety Standard No. 108, Lamps, Reflective Devices, and Associated Equipment, does not require that reflex reflectors bear SAE markings. Although they must meet the requirements of SAE Standard J594f, Reflex Reflectors, January 1977, there is no requirement that they bear SAE markings according to SAE Recommended Practice J759c, Lighting Identification Code, January l975. Although the Federal Highway Administration's Office of Motor Carrier Safety (OMCS) has amended most of its vehicle lighting regulations to conform to Standard No. 108, up until now that agency has required, under 49 CFR 393.26(c), that reflectors bear (among other markings), the letters 'SAE-A'. However, OMCS has informed us that it will amend its regulation to conform to Standard No. 108 as early as convenient, and in the meantime will notify its field office that the marking requirement is no longer to be enforced. Therefore, failure to mark reflectors with the letters 'SAE-A' may be inconsistent with current OMCS requirements, but it is not a failure to comply with Standard No. 108. Further, to the extent that Arizona law itself may require marking of reflectors with the letters 'SAE-A', that provision is inconsistent with Standard No. 108 and is subject to the preemption provisions of l5 U.S.C. 1392(d). Under the preemption provisions, no State or political subdivision thereof may enact or continue in effect a standard covering the same aspect of performance as a Federal motor vehicle safety standard, unless it is identical to the Federal standard. Thus, any State or local requirement for SAE markings on reflex reflectors is one that is not identical to Standard No. 108, and subject to the preemption provisions. Other than the reference to OMCS regulations, we do not know under what authority the Tuscon police are acting. Certainly, a local official cannot enforce a Federal standard per se. If Arizona law requires vehicles in interstate commerce to comply with regulations of the OMCS, and the Tuscon police are attempting to enforce State law, we conclude that the State law is subject to the preemption provisions discussed above, and that such enforcement action has been precluded under Federal law. I hope that this responds to your concerns. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam0500OpenMr. Robert W. Etter, G & D Communications Corporation, 12997 Merriman Road, Livonia, MI 48150; Mr. Robert W. Etter G & D Communications Corporation 12997 Merriman Road Livonia MI 48150; Dear Mr. Etter: This is in reply to your letter of October 22, 1971, and your phon call to Michael Peskoe of November 15, 1971, requesting a copy of the Consumer Information regulations and asking what penalties may be imposed on manufacturers if their vehicles cannot perform as well as the figures they provide pursuant to the regulation. You stated in the above conversation that you have obtained the volume entitled 'Performance Data for New 1971 Passenger Cars and Motorcycles' which contains a copy of the Consumer Information requirements. I have enclosed certain amendments to the Consumer Information regulations which will bring the regulations as they appear in this volume up to date.; With reference to your question regarding penalties for violations o the Consumer Information requirements, Sections 108 and 109 of the National Traffic and Motor Vehicle Safety Act of 1966 (15 U.S.C. SS 1397, 1398) authorize the imposition of civil penalties of up to $1,000 per violation, and up to $400,000 for any related series of violations, against manufacturers whose vehicles cannot perform at least as well as the data they supply indicates. In addition, injunctive proceedings may be utilized pursuant to section 110 of the Act (15 U.S.C. S 1399).; I trust this answers your question. We regret that it was overlooked i our first response to your letter.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam2497OpenMr. Emilio Noriega, 3745 Winston Drive, El Monte, CA 91731; Mr. Emilio Noriega 3745 Winston Drive El Monte CA 91731; Dear Mr. Noriega: This responds to your November 3, 1976, question whether Standard No 121, *Air Brake Systems*, prohibits the installation in a towing vehicle of a service brake control that is designed to permit separate, sequential, or simultaneous actuation of the service brake systems of the towing vehicle and any towed vehicle.; Assuming that the valve for the towing vehicle represents a 'split service brake system as specified in S5.7 of Standard No. 121, such a service brake control design would not conflict with the Standard's requirements. Of course, the actual compliance of any vehicle with Standard No. 121 depends on the actual installation and performance of the system as well as its design.; I would like to note that the agency is not endorsing the service brak control in question by the issuance of this interpretation letter. In fact, the agency is unsure about the effect the control may have on safe braking in a panic situation. Any test information that you or a vehicle manufacturer may care to provide would be appreciated.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam5352OpenMr. Peter Drymalski Investigator Montgomery County Government Office of Consumer Affairs 100 Maryland Avenue Rockville, MD 20850; Mr. Peter Drymalski Investigator Montgomery County Government Office of Consumer Affairs 100 Maryland Avenue Rockville MD 20850; "Dear Mr. Drymalski: This responds to your letter and telephon conversations with David Elias, formerly of this office, asking about a situation you term as the 'cannibalization' of new, unsold vehicles. I apologize for the delay in our response. The situation involves motor vehicle dealers who remove equipment (e.g., a power steering pump) from new vehicles to repair or replace malfunctioning equipment on previously-sold vehicles. The new vehicles are 'cannibalized' to expedite repairs when replacement equipment for the repair is temporarily unavailable. The new vehicles have their cannibalized equipment replaced when the parts become available, before the vehicles are sold. You ask whether the National Highway Traffic Safety Administration (NHTSA) permits dealers to cannibalize parts. As explained below, the answer is yes, provided that certain requirements are met. By way of background, the National Traffic and Motor Vehicle Safety Act ('Safety Act') authorizes NHTSA to issue Federal motor vehicle safety standards ('FMVSS's') applicable to new motor vehicles and items of motor vehicle equipment. Section 108(a)(1)(A) of the Safety Act prohibits any person from manufacturing or selling a new vehicle manufactured on or after the effective date of any applicable FMVSS that does not comply with each of those standards. Under 114 of the Safety Act, each motor vehicle must be certified as conforming to the FMVSS's. NHTSA's certification regulations (49 CFR Part 567) require any person altering (i.e., performing extensive manufacturing operations on) a certified vehicle before the first purchase of the vehicle by the consumer to certify that the vehicle, as altered, conforms to all applicable standards affected by the alteration. 49 CFR 567.7. However, persons altering a certified vehicle only by the addition, substitution, or removal of 'readily attachable components' (e.g., mirrors or tires and rim assemblies) or by performing minor finishing operations (e.g., painting), are not considered alterers, and need not re-certify the vehicle. Whether modifications involve 'readily attachable' components depends on the intricacy of the installation of those components. 'Simple tools, a relatively short installation time, and the ability to install the device without extensively modifying the vehicle would all be factors pointing to a decision that a component is readily attachable.' NHTSA letter to Fred Cords, March 4, 1975. Applying these considerations to the situation you present, we conclude that a power steering pump is a readily attachable component. A power steering pump can be installed with extraordinary ease. The pump can be replaced on the dealer's lot in minutes, simply by opening the hood and popping the old pump out and inserting the new one, with no need to use special tools or have special expertise. The pump can be replaced without extensively modifying the vehicle in any manner. Since the power steering pump is a readily attachable component, the dealer described in your letter is not an alterer under 567.7. The dealer can 'cannibalize' the new unsold cars for power steering pumps and install new pumps when they arrive without applying its own new certification label. I emphasize that a dealer would not be considered an alterer only in the narrow circumstances in which the component being 'cannibalized' is readily attachable. If the component is not readily attachable, the dealer could 'cannibalize' the new cars and later repair and sell them if the following requirements are met. First, the dealer would be responsible under 108(a)(1)(A) of the Safety Act for ensuring that each new vehicle it sells complies with the applicable FMVSS's. Thus, the new vehicle must comply with the FMVSS's. Second, the dealer would be responsible, as an 'alterer,' for certifying the new vehicles from which it removed and replaced the equipment. The dealer would be an alterer since the work performed would be more extensive than 'the addition, substitution, or removal of readily attachable components' or the 'minor finishing operations' described in 567.7. The dealer would certify the vehicle by allowing the original certification label to remain on the vehicle and affixing an additional label of the type and form specified in 567.7. In all cases, including where the dealer is replacing a readily attachable component, the dealer must also adhere to 108(a)(2)(A) of the Safety Act, which provides that: No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard, unless such manufacturer, distributor, dealer, or repair business reasonably believes that such vehicle or item of equipment will not be used... during the time such device or element of design is rendered inoperative. The effect of 108(a)(2)(A) is to limit the modifications that a dealer may make to a new or used vehicle. If, in making the temporary repair affecting a new vehicle, the dealer 'renders inoperative' a device or design installed on the new vehicle pursuant to an FMVSS, the dealer must return the vehicle to compliance before the new vehicle can be sold to the public, or even test- driven by a member of the public. Section 108(a)(2)(A) also applies to the used vehicles into which the cannibalized equipment is installed. The dealer must ensure that it does not violate the Safety Act by 'rendering inoperative' equipment or designs on the vehicles in the process of repairing them. I hope this information has been helpful. If you have any further questions, please contact Deirdre Fujita of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam0150OpenMr. Warren M. Heath, Commander, Engineering Section, Department of California Highway Patrol, P.O. Box 898, Sacramento, CA 95804; Mr. Warren M. Heath Commander Engineering Section Department of California Highway Patrol P.O. Box 898 Sacramento CA 95804; Dear Mr. Heath: Thank you for your letter of January 24, 1969, to Dr. William Haddon Jr., former Director, National Highway Safety Bureau, concerning the installation of front identification lamps on various vehicles manufactured in more than one stage.; Motor Vehicle Safety Standard No. 108 specifies that multipurpos passenger vehicles, trucks, truck tractors, and buses of 80 inches or more in overall width shall be equipped with three identification lamps on the front of the completed vehicle. This standard is applicable to the completed vehicle and it is the responsibility of the final assembler to certify that such vehicle conforms to the standard. A manufacturer of a chassis-cab is not required to mount identification lamps on the chassis-cab. However, if he does so, the manufacturer who adds a body to the chassis-cab is not required to add identification lamps to the front of the body.; Sincerely, Charles A. Baker, Office of Standards on Accident Avoidance Motor Vehicle Safety Performance Service; |
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ID: aiam0445OpenMr. W.R. Kittle, Director, Vehicle Safety and Advance, Quality Control, Chrysler Corporation, P.O. Box 1919, Detroit, MI 48231; Mr. W.R. Kittle Director Vehicle Safety and Advance Quality Control Chrysler Corporation P.O. Box 1919 Detroit MI 48231; Dear Mr. Kittle: This is in reply to your letter of September 10, 1971, concerning th Defects Reports regulations, 49 CFR Part 573. You ask whether S 573.6 (Owner Lists) requires that the list 'show only the latest quarterly status of inspection and defect correction', or whether all prior quarterly lists must also be retained.; Section 573.6 of the regulation requires the owner list to be 'update as of the end of each quarterly reporting period,' with the list being retained for five years after the date on which the defect information report is initially submitted.; We do not consider this section to require all prior quarterly lists t be retained. Therefore if you maintain a list that shows only the latest quarterly status of inspection and defect correction you will be in compliance with the requirements.; We are pleased to be of assistance. Sincerely, Lawrence R. Schneider, 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.