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: aiam4092OpenMr. Carl R. Walker, Manager, Technical Sales and Service, P.T. Brake Lining Company, Inc., P.O. Box 329, Lawrence, MA 01842; Mr. Carl R. Walker Manager Technical Sales and Service P.T. Brake Lining Company Inc. P.O. Box 329 Lawrence MA 01842; Dear Mr. Walker: This responds to your letter addressed to Mr. Richard Radlinski concerning a statement by International Transquip alleging that the National Highway Traffic Safety Administration (NHTSA) and the Bureau of Motor Carrier Safety (BMCS) 'agree' that the Mini-Max brake system produced by that company complies with Federal standards. You noted that International Transquip has referenced a June 6, 1984 letter from BMCS.; NHTSA does not provide approvals of motor vehicles or motor vehicl equipment. Under the National Traffic and Motor Vehicle Safety Act, it is the responsibility of the manufacturer to ensure that its vehicles or equipment complies (sic) with applicable safety standards. I would emphasize that NHTSA has not issued any statement that could be read as 'agreement' that the Mini-Max brake complies with FMVSS No. 121.; We are enclosing a copy of a letter addressed to Navistar whic discusses NHTSA's position concerning the June 6, 1984 letter from BMCS. The letter also notes that the California Highway Patrol (CHP) has raised a number of issues relating to the compliance and overall safety of Mini-Max brakes in connection with a petition for rulemaking, and that International Transquip has submitted comments on CHP's analysis. We have enclosed for your information a notice granting the CHP petition and two related interpretation letters, to International Transquip and the New Jersey Division of Motor Vehicles. The CHP and Mini-Max submissions have been placed in the Petitions for Rulemaking (PRM) Docket for FMVSS No. 121. If you desire copies of those submissions, please contact: Docket Section, National Highway Traffic Safety Administration, Room 5109, 400 Seventh Street, S.W., Washington, DC 20590 (202-426-2768).; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: nht76-4.36Open
DATE: 03/19/76 FROM: AUTHOR UNAVAILABLE; R. L. Carter; NHTSA TO: Almac Plastic Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of February 26, 1976, to Mr. Guy Hunter of my staff, concerning the use of Lucite AR (plastic) glazing materials in rear windows of buses. Your state that a rubber harness has been designed to allow the plastic glazing to be inserted into the rear window openings of the bus. You further state that once inserted into the rubber harness, the glazing can be easily pushed out and therefore would fall within the definition of readily removable windows. Thus, plastic glazing could be used in such windows. It is not clear whether the rear bus window you described in your letter would be classified as a readily removable window as defined in Federal Motor Vehicle Safety Standard (FMVSS) No. 205, Glazing Materials. However, if the glazing can be pushed out as easily as you say, it is clear that it would not meet the window retention requirements specified in FMVSS No. 217, Bus Window Retention and Release. Standard No. 205 specifies requirements for glazing and the vehicle locations in which various types of glazing may be used. The standard prohibits the use of plastic glazing in rear windows of buses unless they are readily removable as defined in the standard. However, in response to a petition submitted by General Motors Corporation, we are currently preparing a Notice of Proposed Rule Making (NPRM) that would amend the standard to permit the use of plastic glazing in all bus windows except windshields and windows to the immediate left and right of the driver. We anticipate that this NPRM will be published in the Federal Register in the near future. A copy of Standard No. 205 and Standard No. 217 were previously mailed to you. If you have any questions, please do not hesitate to contact me. Sincerely, ATTACH. February 26, 1976 Guy Hunter -- NHTSA Dear Mr. Hunter: This is to thank you for the courtesy shown to the writer on the phone. The subject of discussion that we had, was concerning the usage of Lucite AR material on the rear windows of buses. As discussed, the original window on the rear of most buses is quite expensive and due to vandalism, the windows are cracked by rocks and bottles are extremely dangerous to passengers due to the splintering. I am enclosing herewith a schematic brochure that we have created which will more clearly indicate this subject. To accommodate the AA, AC, AD, AB and AE windows a rubber harness has been designed that allows these windows to be inserted. These windows, once inserted into a rubber harness can be easily pushed out with pressure and therefore, can fall into the classification of readily removable windows. This is the major point that I tried to make over the phone. I feel that rear windows can comply with your regulation of usage of Lucite AR windows and are identical to the regulations that permit the usage of Lucite AR on your side windows. If any of this information need further clarification, feel free to call upon Mr. Russell H. Berry of DuPont, the manufacturers of Lucite AR, whose telephone number is 302-774-4639. Or feel free to call the writer Mr. Jack Manne, Engineering Department of Almac Plastics at 212-937-1300. Mr. Berry is extremely knowledgable on this total subject and I am sure that you would find him extremely helpful in any interpretation that is required. Either he or I would be pleased to visit with you in Washington, DC if a meeting would assist your decision in this subject. Thanking you kindly for any attention you give this matter, we beg to remain Very truly yours, Jack Manne -- Engineering Department, ALMAC PLASTICS INC. Enc. CC: R. H. Berry -- DuPont (Brochure Omitted) |
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ID: aiam0663OpenMr. Louis C. Lundstrom, Director, Automotive Safety Engineering, General Motors Technical Center, Warren, MI 48090; Mr. Louis C. Lundstrom Director Automotive Safety Engineering General Motors Technical Center Warren MI 48090; Dear Mr. Lundstrom:This is in reply to your letter of February 28 1972, in which you asked to be referred to the information on which we based our statement in the notice of February 24, 1972, that systems meeting the injury criteria of Standard 208 are available using current seat belt technology.; Research data on the capabilities of seat belts are found in severa places in the public docket, notably in the progress reports from our Safety Systems Laboratory and from Cornell Aeronautical Laboratory (69-7 General Reference Nos. 74, 75, 83, 96, 102, 117, 120 and 135). There are records of vehicle tests in which current lap and shoulder belt systems have met the injury criteria (see, e.g. N13-69-7-20, N13-69-7-37). Also, the record contains information on energy absorbing webbing and anchorages, both of which are improvements within the current state of the art (see, for example, the 6th progress report from Cornell, runs no. 625-630, 69-7 General Reference No. 135, the data from Toyota in N13-69-7-23, and the Takata Koyjo data in N16-69-7-1).; Although the behavior of the head seems to be a greater problem fo belt systems than the behavior of the chest, due in part to the effects of rebound, the changes in the head injury criteria proposed in Notice 17 should ease the problem considerably.; Sincerely, Douglas W. Toms, Administrator |
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ID: aiam0645OpenMr. Russell E. MacCleery, Vice President, Automobile Manufacturers Association, Inc., 1619 Massachusetts Avenue, N.W., Washington, DC 20036; Mr. Russell E. MacCleery Vice President Automobile Manufacturers Association Inc. 1619 Massachusetts Avenue N.W. Washington DC 20036; Dear Mr. MacCleery: This is in reply to your letter of March 3, 1972, in which you asked t be referred to the information on which we based our statement in the notice of February 24, 1972, that systems meeting the injury criteria of Standard 208 are available using current seat belt technology.; Research data on the capabilities of seat belts are found in severa places in the public docket, notably in the progress reports from our Safety Systems Laboratory and from Cornell Aeronautical Laboratory (69-7 General Reference Nos. 74, 75, 83, 96, 102, 117, 120 and 135). There are records of vehicle tests in which current lap and shoulder belt systems have met the injury criteria (see, e.g. N13-69-7-20, N13-69-7-37). Also, the record contains information on energy absorbing webbing and anchorages, both of which are improvements within the current state of the art (see, for example, the 6th progress report from Cornell, runs no. 625-630, 69-7 General Reference No. 135, the data from Toyota in N13-69-7- 23, and the Takata Koyjo data in N16-69-7-1).; Although the behavior of the head seems to be a greater problem fo belt systems than the behavior of the chest, due in part to the effects of rebound, we have proposed changes in the head injury criterion that should ease the problem considerably.; Sincerely, Douglas W. Toms, Administrator |
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ID: nht94-3.55OpenTYPE: INTERPRETATION-NHTSA DATE: July 5, 1994 FROM: Lawrence Farhat -- President/CEO, Neon Riders of America, Inc. TO: John Womack -- Acting Chief Counsel, NHTSA TITLE: NONE ATTACHMT: Attached to letter dated 8/9/94 from John Womack to Lawrence Farhat (VSA 108(a)(2)(A)) TEXT: Dear Mr. Womack: My name is Lawrence Farhat, President/CEO of NEON RIDERS of America, Inc., Jacksonville, Florida. Please accept this as an official written inquiry, regarding under-carriage neon lights, which we have been manufacturing and shipping, both nationally and internationally, for approximately three years. Unfortunately, there has been some confusion, on a state by state level, as to the acceptability and/or legality of the under-carriage neon lights. There are a very few local and state officers that have issued citations for "improper lighting." To the best of our knowledge, when fought in court, these citations have been dismissed by the judge. We offer 10 colors in our product line: purple, pink, green, aqua, orange, tangerine, yellow, white, red and blue. It has been deemed by the State of Florida, that displaying red or blue lights, even under the vehicle and concealed, to be illegal when v isible from the front. Granted, this is a gray area of the law, since most all police and rescue vehicles have blue and red lights. However, police and rescue/emergency vehicles display their lights mounted on top of the vehicle, always flashing and ve ry visible. Our product is mounted under the vehicle, and is concealed to the point where you cannot see the neon light bulb itself. Instead, all you see is the reflection of the light onto the ground. Please see the enclosed photograph, which shows e xactly what the lights look like when installed. There are four tubes, (front, rear and both sides), giving the vehicle the appearance of floating on a cloud of light! Hopefully, you have already seen at least one vehicle with these neon lights under it . Neon light ground effects are considered an accessory to all motor vehicle (cars, trucks, vans, tractor-trailers, motorcycles, boats, ATV's, snowmobiles, and even bicycles). These lights not only serve an aesthetic value, but also, and most important ly, as a safety feature. It is obvious that these neon lights are an innocuous accessory, when installed 2 correctly, under the vehicle. The Jacksonville Sheriff's office has installed blue neon on all of the motorcycles in the department, and their reports have been very, very favorable. A contact name and phone number is available at your request. The New Orleans Police Department, as well as several other city police departments, are also interested in putting neon on their vehicles for safety purposes. We do not feel that our product falls under the description in your Section 108. Neon is not a poisonous gas, nor can it explode . . . this is a fallacy. We consider our manufacturing process to be THE HIGHEST in the industry for quality and safety. I have enclosed a cut-away section of a tube for your inspection. This will give you an idea of how the tubes are assembled, and how well protected the neon bulb itself is. The tube fits inside a metal shield to conceal the tube from direct visual contact . The neon operates off any 12v battery system, with a transformer that produces 9000v, secondary for neon. This transformer, which is about the size of a beeper, has it's own safety factor built into each unit, causing it to automatically shut off if i t detects any problems. Every tube that we distribute is quality control tested prior to shipping. Please inquire with your colleagues as to the validity of our existance as a Florida Corp., manufacturing and distributing these neon light ground effects within the continental United States and abroad. I am looking forward to your response. If you ha ve any questions, or you need any additional information or technical data regarding the lights, please do not hesitate to contact me at the toll-free number printed below. Thank you in advance for your time and consideration. LF/klp |
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ID: aiam1408OpenMr. Elmer Rattner, Rebcor, Inc., P.O. Box 156, 3300 Dixie Highway, Fairfield, OH 45014; Mr. Elmer Rattner Rebcor Inc. P.O. Box 156 3300 Dixie Highway Fairfield OH 45014; Dear Mr. Rattner: This is in reply to your letter of January 11, 1974, and subsequen telephone conversation with Mr. Feldman of this office asking whether the motorcycle helmets you manufacture may be labeled with the DOT symbol before the March 1, 1974, effective date of Standard 218, *Motorcycle Helmets*.; The NHTSA's position is that it would be 'false and misleading,' withi the meaning of the statute, for a DOT symbol to appear without qualification on helmets manufactured before the effective date of the standard. We do, however, consider it permissible to have a DOT symbol on the helmet if it is covered by a label, not easily removable, that states in letters at least one-quarter of an inch high:; >>>NO FEDERAL MOTOR VEHICLE SAFETY STANDARD APPLIES TO THIS HELMET.<<< Further, since the requirements of the standard only apply to helmet that fit headform size C, manufactured on or after March 1, 1974, and will not apply to helmets that do not fit headform size C until extended to those sizes by a future amendment to the standard, the DOT symbol required for helmets that fit headform size C should not appear on any other helmets until the standard is made effective for those other sizes.; You also asked whether a manufacturer would be allowed to label helmet with a statement to the effect that, although no Federal motor vehicle safety standard applies to a helmet of that size, it meets all Federal performance requirements for helmets of other sizes. We would have no objection to such a statement, provided the manufacturer ensures that it is true.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam1406OpenMr. Elmer Rattner, Rebcor, Inc., P.O. Box 156, 3300 Dixie Highway, Fairfield, OH 45014; Mr. Elmer Rattner Rebcor Inc. P.O. Box 156 3300 Dixie Highway Fairfield OH 45014; Dear Mr. Rattner: This is in reply to your letter of January 11, 1974, and subsequen telephone conversation with Mr. Feldman of this office asking whether the motorcycle helmets you manufacture may be labeled with the DOT symbol before the March 1, 1974, effective date of Standard 218, *Motorcycle Helmets*.; The NHTSA's position is that it would be 'false and misleading,' withi the meaning of the statute, for a DOT symbol to appear without qualification on helmets manufactured before the effective date of the standard. We do, however, consider it permissible to have a DOT symbol on the helmet if it is covered by a label, not easily removable, that states in letters at least one-quarter of an inch high:; >>>NO FEDERAL MOTOR VEHICLE SAFETY STANDARD APPLIES TO THIS HELMET.<<< Further, since the requirements of the standard only apply to helmet that fit headform size C, manufactured on or after March 1, 1974, and will not apply to helmets that do not fit headform size C until extended to those sizes by a future amendment to the standard, the DOT symbol required for helmets that fit headform size C should not appear on any other helmets until the standard is made effective for those other sizes.; You also asked whether a manufacturer would be allowed to label helmet with a statement to the effect that, although no Federal motor vehicle safety standard applies to a helmet of that size, it meets all Federal performance requirements for helmets of other sizes. We would have no objection to such a statement, provided the manufacturer ensures that it is true.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam1978OpenClark Brown, Esq., Richards, Watson, Dreyfuss & Gershon, 615 South Flower Street, Los Angeles, CA 90017; Clark Brown Esq. Richards Watson Dreyfuss & Gershon 615 South Flower Street Los Angeles CA 90017; Dear Mr. Brown: This is in response to your letter of May 19, 1975, in which yo request an interpretation that roof vent covers in recreational vehicles are excluded from the coverage of Motor Vehicle Safety Standard No. 205. Further, you ask our interpretation of the extent to which States may procedurally regulate the conformity of motor vehicles and motor vehicle equipment with Federal safety standards.; We have reviewed the extensive brief you submitted in relation to th applicability of Standard No. 205 to recreational vehicle roof vent covers manufactured by injection molding, and have determined that roof vent covers fall within the purview of the Standard. Nevertheless, we concur in your view that roof vent covers manufactured by the injection molding process are not susceptible to testing under the procedures found in USAS Z26.1. Consequently, we intend to issue in the near future proposed rulemaking which would establish a surrogate testing procedure for this type of roof vent cover. Until this new procedure is adopted, the NHTSA intends to take no action against manufacturers who do not certify that their injection molded roof vent covers meet the requirements of Standard No. 205 which incorporate the requirements of USAS Z26.1.; With respect to State action concerning the conformity of moto vehicles and equipment to motor vehicle safety standards, we are currently reviewing our position in light of a suit brought last month against the State of Pennsylvania. We shall advise you when a conclusion has been reached.; Sincerely, James C. Schultz, Chief Counsel |
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ID: aiam2123OpenMr. J. A. Davies, Realco Services, Inc., 175 West Jackson Blvd., Chicago, IL 60604; Mr. J. A. Davies Realco Services Inc. 175 West Jackson Blvd. Chicago IL 60604; Dear Mr. Davies: This responds to Realco Services' October 10, 1975, question whethe the replacement of the four rails in the sides of a monocoque-type van would qualify as a vehicle assembly operation subject to certification to new vehicle standards, including Standard No. 121, *Air Brake Systems*.; The answer to your question is no. The position of the NHTSA wit regard to the use of used trailer components that was discussed in the Stainless Tank and Equipment interpretation letter applies only to situations in which a new trailer body is installed on used running gear. These limitations do not apply where most of the used body (along with used running gear) is retained, as where one or more rails are replaced in the sides of a used monocoque van.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: nht79-3.7OpenDATE: 08/27/79 FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA TO: Shaeen, Lumberg, Callaghan and Berke TITLE: FMVSS INTERPRETATION TEXT: This is in response to the questions you raised with Ms. Debra Weiner of my office in a telephone conversion of July 9, 1979. Specifically, you asked whether there are any current or proposal regulations applicable to customizers who install plastic auxiliary diesel fuel tanks in Mercedes automobiles. You noted these vehicles would typically be purchased from a dealer and then brought to the customizer for installation of the auxiliary tank. The National Traffic and Motor Vehicle Safety Act, as amended 1974 (the Act), authorizes the National Highway Traffic Safety Administration (NHTSA) to issue Federal Motor Vehicle Safety Standards applicable to motor vehicles and to equipment for installation in vehicles. Safety Standard No. 301-75, Fuel System Integrity (49 CFR 571.301-75), specifies performance requirements for vehicles, including passenger cars, which use fuel with a boiling point above 32 degrees F. (This includes both gasoline and diesel fuel). Under the standard's requirements, no part of a vehicle's entire fuel system can have fuel spillage beyond certain specified amounts during barrier crash tests. Specific performance requirements for individual components of the fuel system, such as the fuel tank, are not currently included in the standard. With the advent of high density polyethlene (plastic) fuel tanks, however, the current "system" performance requirements night not be sufficient to ensure the integrity of vehicle fuel systems. For this reason, the agency recently published an Advance Notice of Proposed Rulemaking concerning the advisability of establishing performance standards for plastic tanks (44 FR 33441, June 11, 1979 copy enclosed). Under section 108 of the Act, new motor vehicles must comply with Federal safety standards prior to their first purchase in good faith for purposes other than resale. That purchase is completed when the vehicle is delivered to the ultimate consumer. Thus, the extent to which a customizer must ensure that his installation of an auxiliary tank complies with Safety Standard No. 301-75 depends upon whether the tank is installed before or after this delivery. A customizer who installs an auxiliary fuel tank prior to the vehicle's first purchase would be a vehicle "alterer". Under the provisions of 49 CFR 567.7, he would be required to place an additional label on the vehicle specifying that, as altered, the vehicle continues to be in compliance with all applicable safety standards, including Standard No. 301-75. Additionally, the alterer would be responsible for any safety related defects arising from the installation of the auxiliary tank and would be required under section 151 of the Act to provide notice of and remedy for the defective installation. If a customerizer installs an auxiliary tank in a vehicle after its delivery to the first purchaser he could be subject to section 108(a)(2)(A) of the Act. That section 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. . . . A person or entity found to have violated this section would be liable for a civil penalty of up to $ 1,000 for each violation. (Section 109 of the Act). If a person subject to section 108(a)(2)(A) adds an auxiliary gasoline tank to a vehicle manufactured in accordance with Safety Standard No. 301-75, and in the process knowingly reduces the performance of the fuel system originally installed in the motor vehicle, he or she has violated section 108(a)(2)(A). (H.R. No. 1191, 93d Cong., 2d Sess. 34 (1974). Such reduction of performance could occur, for example, if gasoline from the original system (a fuel system includes the filler pipe, tank gasoline lines, fuel pump, carburetor, and engine) could be leaked through a rupture in the the auxiliary tank and fuel lines, and if the design materials, construction, installation or location of the auxiliary tank and fuel lines made them more susceptible to rupture than the original fuel system. Please note that a customizer would be considered a "motor vehicle repair business" since he modifies motor vehicles for compensation. I hope that you will find this response helpful. |
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.