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: aiam0006OpenMr. William A. Batten Eaton Corporation Truck Components Operations P.O. Box 4013 Kalamazoo, MI 49003; Mr. William A. Batten Eaton Corporation Truck Components Operations P.O. Box 4013 Kalamazoo MI 49003; Dear Mr. Batten: This responds to your letter and telephon conversation with Ms. Fujita of my staff concerning Federal Motor Vehicle Safety Standard (FMVSS) No. 124, Accelerator Control Systems. You asked about the standard's 'applicable mileage requirement or time domain' for a truck with a gross vehicle weight rating greater than 10,000 pounds. You informed Ms. Fujita that, stated differently, your question is whether NHTSA requires a used vehicle to continue to meet an FMVSS, and if the answer is yes, for what mileage or amount of time the vehicle must meet the standard. Generally speaking, the answer is no. NHTSA is authorized by the National Traffic and Motor Vehicle Safety Act (Safety Act) to regulate the manufacture and sale of new motor vehicles and motor vehicle equipment. The Safety Act requires a vehicle to comply with applicable FMVSS's until its first purchase in good faith for purposes other than resale. However, you should be aware that manufacturers, distributors, dealers, or motor vehicle repair businesses modifying a vehicle (new or used) are prohibited by section 108(a)(2)(A) of the Safety Act from knowingly rendering inoperative any device or element of design installed on or in a motor vehicle in compliance with an applicable FMVSS. Thus, in the context of Standard No. l24, a person in the aforementioned categories is prohibited from rendering inoperative an accelerator control system that has been installed in compliance with that standard. In addition, if the in-use deterioration of the performance of a vehicle or one of its components creates a safety risk, it could constitute a safety-related defect. Pursuant to sections l5l-l54 of the Safety Act, manufacturers are required to notify NHTSA and owners of such safety-related defects and to remedy such defects without charge. Thus, if the accelerator control systems on your vehicles deteriorate such that they no longer would comply with Standard No l24 and create an unsafe situation, that could be the basis for a defect determination, even though the vehicles met all applicable safety standards when they were new. I also note that our sister agency in the Department, the Federal Highway Administration (FHWA), has operational and equipment requirements for trucks used in interstate commerce. If you are interested in that agency's requirements, you can write to them at the following address: Office of Motor Carrier Standards Federal Highway Administration 400 Seventh Street, S.W. Washington, D.C. 20590 I hope this information is helpful. Sincerely, Paul Jackson Rice Chief Counsel; |
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ID: aiam5204OpenMr. Bob Davis Quality Control Manager Horton Emergency Vehicles 500 Industrial Mile Road Columbus, OH 43228; Mr. Bob Davis Quality Control Manager Horton Emergency Vehicles 500 Industrial Mile Road Columbus OH 43228; Dear Mr. Davis: This is in response to your letter of April 13, 1993 requesting an interpretation of Federal Motor Vehicle Safety Standard (FMVSS) No. 206 as it affects the rear doors of ambulances that your company manufactures. I apologize for the delay in responding. You state that your ambulances have two rear doors, and that each has locking mechanisms that can be operated both from the outside and inside of the doors. Your specific question is whether you can eliminate the inside locking mechanism on one of the rear doors without violating Standard No. 206. The language in S4.1.3 of Standard No. 206 that you noted in your letter (i.e., 'Each door shall be equipped with a locking mechanism with an operating means in the interior of the vehicle.') refers to side doors, but not to rear doors. Thus, your company's ambulances need not be equipped with locking mechanisms on each rear door. I hope this information has been helpful. If you have any further questions feel free to contact David Elias of my office at the above address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam0456OpenMr. Davis Piper, Vice President, Forse Cleanamation, 1500 West Second Street, Anderson, IN 46011; Mr. Davis Piper Vice President Forse Cleanamation 1500 West Second Street Anderson IN 46011; Dear Mr. Piper: This is in reply to your letter of September 29, 1971, to Mr. J.E Leysath of this Office requesting information relative to the lighting requirements applicable to your E-Z Tow towing unit.; The E-Z Tow unit is a 'motor vehicle' as defined by the Nationa Traffic and Motor Vehicle Safety Act of 1966 since it is a 'vehicle . . . drawn by mechanical power manufactured primarily for use on the public streets, roads, and highways.' However, since it is designed to 'tow' rather than to 'carry' property, the E-Z Tow unit is not a 'trailer' as defined for purposes of the Federal Motor Vehicle Safety Standards. Since it is an unclassified 'motor vehicle,' the lighting requirements of Federal Motor Vehicle Safety Standard No. 108 are not applicable, therefore, you need only to comply with the lighting requirements of the States in which you sell or use the unit.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam4946OpenThomas A. Gerke, Esq. Smith, Gill, Fisher & Butts 1200 Main St., Suite 3500 Kansas City, MO 64105-2152; Thomas A. Gerke Esq. Smith Gill Fisher & Butts 1200 Main St. Suite 3500 Kansas City MO 64105-2152; "Dear Mr. Gerke: This responds to your December 23, 1991 lette concerning Safety Standard 107, Reflecting Surfaces. You asked us to confirm the interpretation of the standard set forth in my September 3, 1991 letter to Mr. Thomas Steinhagen. The interpretation is correct. My letter to Mr. Steinhagen was about the applicability of Standard 107 to a replacement windshield wiper arm and blade, a type of motor vehicle equipment that your client, Rally Manufacturing, seeks to sell. You state that Rally ceased producing certain windshield wiper arms and blades after NHTSA's Enforcement office notified Rally that it appeared the products did not meet the requirements of Standard 107. My letter to Mr. Steinhagen clarified the requirements of Standard 107 and the Vehicle Safety Act. I emphasized the following points in the letter: 1. Standard 107 applies to new motor vehicles, and not to items of motor vehicle equipment, such as a replacement wiper arm and blade. Replacement wiper arms and blades may be sold to consumers without violating Federal law, even if the component does not conform to the requirements of Standard 107. 2. Section 108(a)(2)(A) of the Safety Act prohibits any manufacturer, distributor, dealer or motor vehicle repair business from 'rendering inoperative' any device or element of design installed in or on a vehicle in compliance with an applicable safety standard. If a person in the aforementioned categories installed a wiper arm and blade that did not conform to the requirements of Standard 107, the person would violate 108(a)(2)(A). 3. The prohibition of 108(a)(2)(A) does not apply to individual vehicle owners who alter their own vehicles. Thus, individual owners may install any item of motor vehicle equipment regardless of its effect on compliance with Federal motor vehicle safety standards. However, NHTSA encourages vehicle owners not to tamper with vehicle safety equipment if the modification would degrade the safety of the vehicle. 4. Regardless of whether Standard 107 applies to the replacement arm and blade, the device is subject to the requirements in 151-159 of the Safety Act concerning the recall and remedy of products with safety defects. If the manufacturer or NHTSA determines that a safety-related defect exists either in an arm and blade that conforms to Standard 107 or in one that does not, the manufacturer must notify purchasers of the product and remedy the problem free of charge. In your letter, you specifically ask about the sale of a replacement wiper blade 'by a wholesaler/distributor to retail stores and other similar customers without any installation service by the wholesaler/distributor.' The sale is not prohibited by Standard 107 or 108(a)(2)(A). However, the retail store or 'other similar customer' would be considered a dealer under 102(7) of the Safety Act, and thus subject to the 'render inoperative' prohibition of 108(a)(2)(A). While the dealer may sell the replacement blade, the dealer would be prohibited from installing it on a motor vehicle. I regret any confusion resulting from NHTSA's letters to your client. If you have further questions, please do not hesitate to contact my office. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam5654OpenFred H. Pritzker, Esq. Pritzker & Meyer, P.A. Suite 1275 Peavey Building 730 Second Avenue South Minneapolis, Minnesota 55402; Fred H. Pritzker Esq. Pritzker & Meyer P.A. Suite 1275 Peavey Building 730 Second Avenue South Minneapolis Minnesota 55402; "Dear Mr. Pritzker: This concerns your August 29, 1995 letter about th replacement of a rear seat in a 1993 GEO Tracker with a speaker box. In response to your request that we speak with you about the issues raised in that letter, Mr. Edward Glancy of my staff spoke with you by telephone. In that conversation, you requested a written opinion. Our opinion is set forth below. According to your letter, the son of the Tracker owner took the vehicle to the local outlet of a national electronics 'super store' to upgrade the vehicle's automobile stereo equipment. An employee of that store removed the rear seat and replaced it with a speaker box. As part of this process, the female portion of the seat belt buckle was removed. You stated that the speaker box has a ledge not unlike a bench-type seat, the speaker box was strong enough for a person to sit on, and was carpeted. You represent a person who was sitting on this speaker box when the vehicle was involved in a serious collision, and believe that the electronics company violated the 'make inoperative' provision of Federal law, 49 U.S.C. 30122(b). As Mr. Glancy explained to you by telephone, NHTSA cannot make a determination as to whether a company violated the 'make inoperative' provision outside a compliance proceeding. I can, however, provide general information on how this provision applies in such a situation. By way of background information, the National Highway Traffic Safety Administration (NHTSA) is authorized to issue Federal motor vehicle safety standards applicable to the manufacture and sale of new motor vehicles and items of motor vehicle equipment. NHTSA has exercised this authority to establish Federal Motor Vehicle Safety Standard No. 208, Occupant Crash Protection (49 CFR 571.208), which specifies performance requirements for the protection of vehicle occupants in crashes. Standard No. 208 required model year 1993 passenger cars and other light vehicles to have a Type 2 (lap/shoulder) seat belt assembly at each forward-facing rear outboard designated seating position, and either a Type 1 (lap) or Type 2 seat belt assembly at all other rear designated seating positions. NHTSA's safety standards apply only to new motor vehicles and new motor vehicle equipment. However, section 30122(b) applies in the case of used as well as new vehicles. That section reads as follows: A manufacturer, distributor, dealer, or motor vehicle repair business may not knowingly make inoperative any part of a device or element of design installed on or in a motor vehicle or motor vehicle equipment in compliance with an applicable safety standard prescribed under this chapter unless the manufacturer, distributor, dealer, or repair business reasonably believes the vehicle or equipment will not be used (except for testing or a similar purpose during maintenance or repair) when the device or element is inoperative. I can offer the following thoughts concerning how section 30122(b) would apply in the context of a manufacturer, distributor, dealer or motor vehicle repair business removing rear seat belts. First, electronics companies which install stereo equipment in motor vehicles are subject to section 30122(b), given the broad language 'manufacturer, distributor, dealer or motor vehicle repair business.' Second, some specific examples will illustrate how answering the question of whether a particular action makes inoperative a device installed in compliance with a Federal safety standard depends on the underlying factual circumstances. As noted above, under Standard No. 208, seat belts were required to be installed at the rear designated seating positions in the Tracker. The definition of 'designated seating position,' set forth in 49 CFR 571.3, reads as follows: Designated seating position means any plan view location capable of accommodating a person at least as large as a 5th percentile female, if the overall seat configuration and design and vehicle design is such that the position is likely to be used as a seating position while the vehicle is in motion, except for auxiliary seating accommodations such as temporary or folding jump seats. . . . The simple removal of rear seat belts from designated seating positions, without other modifications to a vehicle, would obviously make inoperative a device, i.e., seat belts, installed in compliance with Standard No. 208. Similarly, the removal of rear seat belts, coupled with replacing the rear seat with another rear seat, would make the seat belts inoperative (assuming the rear seat belts were not replaced). However, if rear seat belts were removed as part of permanently converting a passenger van to a cargo van by removing the rear seat, the removal of the seat belts would not make inoperative a device installed in compliance with a safety standard. This is because Standard No. 208 would not have required rear seat belts in the absence of rear designated seating positions. Your letter raises the question of whether a speaker box of the type installed by the electronics company would be considered to provide designated seating positions. I have enclosed a copy of the final rule establishing the designated seating position definition (44 FR 23229, April 19, 1979). As discussed in that notice, any position likely to be used while the vehicle is in motion will be considered a designated seating position. The notice includes several discussions which are relevant to the issue of whether a position is likely to be used while the vehicle is in motion. Included is a discussion that a manufacturer would not be responsible for abusive or unorthodox use of a particular position. If you have further questions, please feel free to call Mr. Glancy at (202) 366-2992. Sincerely, Samuel J. Dubbin Chief Counsel Enclosure"; |
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ID: aiam2191OpenHonorable Robin Beard, Member of Congress, 710 North Garden Street, Columbia, TN 38401; Honorable Robin Beard Member of Congress 710 North Garden Street Columbia TN 38401; Dear Mr. Beard: This responds to your January 29, 1976, question whether an owner of vehicle manufactured to comply with Standard No. 121, *Air Brake Systems, may legally disconnect portions of the brake system after a vehicle has been delivered for use in his business.; Section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safet Act (15 U.S.C. S 1397(a)(2)(A)) prohibits, with one exception, knowing disconnection of safety components by manufacturers, distributors, dealers, or repair businesses. Thus, there is no prohibition on disconnection by an owner of his own vehicle's system under the Traffic Safety Act. However, State statutes, or the regulations of the Bureau of Motor Carrier Safety may prohibit disconnection. In any case, the NHTSA urges that owners not disconnect safety devices without consultation with the vehicle manufacturer with regard to the safest configuration of the vehicle.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam0821OpenMr. Louis C. Lundstrom, Director, Automotive Safety Engineering, General Motors Corporation, General Motors Technical Center, Warren, MI 48090; Mr. Louis C. Lundstrom Director Automotive Safety Engineering General Motors Corporation General Motors Technical Center Warren MI 48090; Dear Mr. Lundstrom: This is in reply to your letter of August 21, 1972, on the subject o the operation of the seat belt warning system when the vehicle is in one of the free start modes allowed by S7.4.3 and S7.4.4 of Standard No. 208.; You are correct in your understanding that S7.3.5.4 does not requir the warning to operate when the ignition switch is in the 'start' position if the conditions described in S7.4.3 and S7.4.4 exist. Under those conditions, the interlock system continues to act as if the operation of the belt systems had not been followed by their release. By the same logic, the warning system activation required by S7.3.5.4 is in abeyance until the ending of the free start conditions.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1699OpenMr. Scott B. Miller, Hadco Engineering, 2000 Camfield Avenue, Los Angeles, CA 90040; Mr. Scott B. Miller Hadco Engineering 2000 Camfield Avenue Los Angeles CA 90040; Dear Mr. Miller: This responds to your November 13, 1974, question whether a combinatio vehicle which consists of an air braked truck tractor and an electrically-braked trailer would be subject to the requirements of Standard No. 121, *Air brake systems*, effective January 1, 1975, for trailers and March 1, 1975, for trucks and buses. The electric brakes on the trailer would be actuated by a Warner Electric brake controller that is designed to be mounted in the truck's air control line and to respond to air brake signals generated by the truck's service brake control.; Standard No. 121 applies to trucks, buses, and trailers equipped wit air brake systems. Therefore, the trailer which is electrically-braked is not required to comply with the standard.; It appears from the Warner literature that you enclosed that the truc tractor would be equipped with air brakes and would therefore have to comply with the standard. I would like to point out that air-braked truck tractors manufactured after March 1, 1975, must be certified to comply with the requirements of the air brake standard. If a person modifies the air brake lines on such a truck tractor before the first retail purchase by the addition of the Warner controller, that person must certify that the truck still meets the standard as modified.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam4161OpenMr. Gary D. Clark, John Deere Tractor Works, P.O. Box 3500, Waterloo, IA 50704-3500; Mr. Gary D. Clark John Deere Tractor Works P.O. Box 3500 Waterloo IA 50704-3500; Dear Mr. Clark: This responds to your letter dated February 27, 1986, concerning you projected sale of a strip chassis for the class A motor home industry. The identifying information submitted in your letter is being referred to the Office of Vehicle Safety Standards which keeps records of manufacturer identification in accordance with 49 CFR Part 566.; Under S114 of the National Traffic and Motor Vehicle Safety Act o 1966, as amended, each manufacturer is responsible for certifying that its motor vehicles and motor vehicle equipment comply with all applicable safety standards. This agency does not require that a manufacturer's documents and test data, which form the basis for this certification, be submitted unless requested by the agency.; I hope this information is helpful to you. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1363OpenMr. Evan Hammond, Manager - Central Engineering, Trailmobile Technical Center, 5570 Creek Road, Cincinnati, OH, 45242; Mr. Evan Hammond Manager - Central Engineering Trailmobile Technical Center 5570 Creek Road Cincinnati OH 45242; Dear Mr. Hammond: This is in reply to your letters of October 25, and December 14, 1973 I regret that your earlier letter did not arrive.; You stated that your customer wishes to mount rear identification lamp at the same height from the ground as the rear turn signal, stop, tail and clearance lamps, and that, because of the shallowness of the rear header area it is not 'practicable' to mount them there.; Although it may not be 'practicable' to mount the Grote 272 lamp, specified by your customer, in the header area, there may b other conforming lamps that it would be 'practicable' to mount in that location in a three-lamp identification array. If such lamps are available, then Standard No. 108 takes priority over contractual specifications, especially since the clearance lamps will be mounted at a point other than 'as close as practicable to the top of the vehicle'.; Yours truly, Richard By. Dyson, Assistant 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.