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: aiam4773OpenHerr Hanno Westermann Hella KG Hueck & Co Postfach 28 40 4780 Lippstadt W. Germany; Herr Hanno Westermann Hella KG Hueck & Co Postfach 28 40 4780 Lippstadt W. Germany; Dear Herr Westermann: This is in reply to your letter to Dr. Burgett o this agency with respect to 'multi bulb devices', specifically 'how the requirements for one-, two-, or three compartment lamps (lighted sections) as it is documented in FMVSS No. 108, Figure lb have to be interpreted. . . .' You have asked this question because 'Hella would like to equip motor vehicles with signalling devices which have --opposite to conventional lamps--a great number of replaceable miniature bulbs instead of e.g. one 32 cp bulb.' Your question assumes that Standard No. 108 is to be interpreted in a manner that equates the number of lighted sections with the number of bulbs providing the light. Finally, you have stated that the total area of the lamp is not larger than current one-compartment lamps. We regret the delay in responding to your letter, but we have recently completed rulemaking, begun in September l988, which is relevant to your question. On May 15, l990, an amendment to Standard No. 108 was published, effective December 1, l990, the effect of which is to restrict Figure 1b to replacement equipment. I enclose a copy of the amendment for your information. Your question relates to 'signalling devices' for new motor vehicles, and Figure 1b shows that, specifically, you refer to turn signal lamps. Beginning December l, l990, Standard No. 108 will specify two different standards for turn signal lamps. If the lamp is intended for use on multipurpose passenger vehicles, trucks, buses, and trailers whose overall width is 80 inches or more, it must be designed to conform to SAE Standard J1395 APR85 Turn Signal Lamps for Use on Motor Vehicles 2032 mm or More in Overall Width. SAE J1395 also provides that these lamps may be used on vehicles less than this width, except for passenger cars. If a motor vehicle is not equipped with a turn signal lamp designed to conform to SAE J1395, it must be equipped with a turn signal lamp designed to conform to SAE Standard J588 NOV84 Turn Signal Lamps for Use on Motor Vehicles Less Than 2032 mm in Overall Width. In the May l990 amendments, section S3 of Standard No. 108 was amended to add a definition for 'Multiple Compartment Lamp'. Such a lamp is 'a device which gives its indication by two or more separately lighted areas which are joined by one or more common parts, such as a housing or lens.' The multiple bulb device that you described appears to meet this definition. SAE J1395 establishes luminous intensity minima and maxima photometric requirements without reference to either compartments or lighted sections, and all that is required is for the lamp to comply at the individual test points specified. New section S5.1.1.31 clarifies that measurements of a multiple compartment turn signal lamp on vehicles to which SAE J1395 applies are to made for the entire lamp and not for the individual compartments. However, SAE J588 NOV84 continues to specify different minimum photometric requirements for one, two, and three 'lighted sections'. Because the SAE does not prescribe photometric requirements for more than three lighted sections, we have concluded that any device that contains more than three lighted sections need only comply with the requirements prescribed for three lighted sections. I hope that this is responsive to your request. Sincerely, Paul Jackson Rice Chief Counsel; |
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ID: aiam1571OpenMr. John H. Mueller,The Weatherhead Company,300 East 131st Street,Cleveland, Ohio 44108; Mr. John H. Mueller The Weatherhead Company 300 East 131st Street Cleveland Ohio 44108; Dear Mr. Mueller:#This responds to your July 10, 1974, request t modify the hose labeling provisions of Standard No. 106-74, *Brake hoses*, to permit DOT labeling of 1/8-inch O.D. nylon tubing.#To the best of our knowledge 1/8-inch O.D. tubing is not used as brake hose as it is defined by the standard:#>>>'Brake hose' means a flexible conduit manufactured for use in a brake system to transmit or contain the fluid pressure or vacuum used to apply force to a vehicle's brakes'<<<#The tubing is used for pressure gauge lines and in two-speed differentials, but is apparently not used to transmit or contain the pressure used to apply force to a vehicle's brakes. As it is not considered to be brake hose under the standard, it should not be labeled with the DOT symbol.#Aside from this prohibition on the use of the DOT symbol, you are free to label 1/8-inch O.D. nylon tubing as you choose.#Yours truly,Richard B. Dyson,Acting Chief Counsel; |
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ID: aiam4289OpenMr. George Ziolo, 16182 Arena Drive, Ramona, CA 92065; Mr. George Ziolo 16182 Arena Drive Ramona CA 92065; Dear Mr. Ziolo: This letter responds to your inquiry concerning Federal Motor Vehicl Safety Standard No. 111. I apologize for the delay. As I understand your question, you are concerned with a passenger car whose inside rearview mirror apparently does not meet the field-of-view specifications in S5.1 of FMVSS 111 and therefore that must have an outside passenger side mirror in order to comply with the standard. You wish to know whether the need to inscribe the convex mirror in accordance with S5.4.2 is eliminated when the passenger side of the car has both a complying mirror of unit magnification and a convex mirror.; Please understand that the National Highway Traffic Safet Administration (NHTSA) does not approve motor vehicles or motor vehicle equipment. Under the National Traffic and Motor Vehicle Safety Act, it is the manfuacturer's responsibility to ensure that its vehicle or equipment complies with applicable standards. Therefore, this letter is an opinion based on the facts you provide in your letter.; The answer to your question is 'yes.' The passenger side of a new ca would need an outside convex mirror inscribed in accordance with S5.4..2 only if its inside rearview mirror failed to meet the S5.1.1 field of view specifications, and the manufacturer chose to comply with the requirement of S5.3 for an outside passenger side mirror by installing a convex passenger-side mirror. S5.4 provides that the requirements in S5.4.1 - S5.4.3 are applicable to a convex mirror only if that mirror is used to comply with S5.3. In your example, a mirror of unit magnification is used to comply with S5.3. I should add that the manufacturer would have to ensure that installing the convex mirror does not take the mirror of unit magnification out of compliance with FMVSS 111.; Please let me know if you have any further questions. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam4323OpenMr. Albert Schwarz, Senior Engineer, Product Development, Imperial Clevite Inc., Imperial Eastman Division, 6300 W. Howard Street, Chicago, IL 60648-3492; Mr. Albert Schwarz Senior Engineer Product Development Imperial Clevite Inc. Imperial Eastman Division 6300 W. Howard Street Chicago IL 60648-3492; Dear Mr. Schwarz: This responds to your January 12, 1987 letter to the National Highwa Traffic Safety Administration (NHTSA) concerning Standard No. 106, *Brake Hoses.* You ask whether the standard applies to flexible conduits (i.e., hoses and plastic tubing) used to transmit air pressure to accessories such as horns and Windshield wipers. The answer to your question is yes, if a failure of such a conduit results in a loss of air pressure in the brake system.; On August 3, 1984, NHTSA issued an interpretation of Standard No. 10 to Mr. Terry Teeter of the Eaton Corporation, who asked the same question you did about the applicability of the standard to conduits used for accessories. Our letter explains that flexible hoses (and tubing) connected to accessories are 'brake hoses' and subject to the standard if they transmit or contain the air pressure used to apply force to the vehicle s brakes--i.e., a failure of such a hose would result in a loss of air pressure in the brake system. I have enclosed a copy of our letter to Mr. Teeter for your information.; I understand that Ms. Hom of my staff sent you a copy of a Federa Register notice issued by NHTSA on April 17, 1986, which terminated rulemaking on whether the air brake hose tensile requirement of Standard No. 106 should be reduced for hoses typically used for accessories. NHTSA decided to terminate rulemaking because the agency believed that it would be in the interest of safety for the smaller-diameter hoses to comply with current requirements of the standard. Since you might want to review this notice in light of the information provided you in this letter, I have enclosed a duplicate for your convenience.; You also ask whether there are requirements other than those include in Standard No. 106 that must be met by accessory lines. The answer to your question is no. The air brake hoses you intend to use in accessory lines need comply only with Standard No. 106 to be manufactured and sold in this country.; I hope this information is helpful. Please contact my office if yo have further questions.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1121OpenMr. W. H. Blaine, Manager, Southern California Edison Company, Automotive; Mr. W. H. Blaine Manager Southern California Edison Company Automotive; Dear Mr. Blaine: This is in response to your letter of April 13, 1973, in which you as whether the installation of a truck body or derrick on a new chassis-cab by your company for its own use makes it a final-stage manufacturer subject to the identification and certification provisions implementing the Highway Traffic and Motor Vehicle Safety Act, Public Law 89- 563.; The answer to your question is yes. The completion of a motor vehicl by a manufacturer for its own use does not relieve it of responsibility for certification.; As a final-stage manufacturer, you are required to submit th information specified in 49 CFR Part 566, Manufacturer Identification. I am enclosing a copy of Part 566 for your information. No specific format is required, and a letter report will suffice.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam5162OpenAIR MAIL Mr. T. Kouchi Director Stanley Electric Co., Ltd. 2-9-13, Nakameguro, Meguro-ku Tokyo 153, Japan; AIR MAIL Mr. T. Kouchi Director Stanley Electric Co. Ltd. 2-9-13 Nakameguro Meguro-ku Tokyo 153 Japan; Dear Mr. Kouchi: This responds to your letter of April 2, 1993, to Pau Jackson Rice, the former Chief Counsel of this agency. You refer to Mr. Rice's letter of December 30, 1992, which you interpret as saying that 'any device that contains more than three lighted sections, or LEDs, need only comply with the requirements prescribed for three lighted sections.' You consider 'that the lamps having three lighted sections described in the attached drawing No. 1 & No. 2 need only comply with the photometric requirements prescribed for three lighted sections.' You ask 'if our idea is appropriate.' We confirm your interpretation with respect to drawing No. 1, which appears essentially the same as covered by Mr. Rice's interpretation. With respect to drawing No. 2, this lamp appears to be composed of a panel of LEDs flanked by two incandescent bulbs. When the LED panel alone is operated, or when it is operated in conjunction with either one or both of the incandescent bulbs the requirements applicable to three lighted sections will apply. However, each bulb is regarded as being a single light source so that if the bulbs are operated individually, only the requirements for single lighted sections apply. If the bulbs are operated simultaneously to perform the same function, the requirements for two lighted sections apply. However, if the bulbs are operated simultaneously to perform different functions, the single lighted section requirements apply and all other requirements such as contrast ratios (e.g., the l:5 for tail and stop lamps) must be met. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam1988OpenMr. W.J. Joyce, Jr.,Consultant, International Business,Grosse Pointe Plaza Bldg.,22725 Mack Avenue,St. Clair Shores, Michigan 48080; Mr. W.J. Joyce Jr. Consultant International Business Grosse Pointe Plaza Bldg. 22725 Mack Avenue St. Clair Shores Michigan 48080; Dear Mr. Joyce:#This responds to your June 18, 1975, question whethe S5.3 of Standard No. 105-75, *Hydraulic Brake Systems*, requires that the brake fluid level warning system specified by S5.3.1 be instantaneous when the brake fluid level reaches the condition described in S5.3.1(b).#The answer to your question if no. The National Highway Traffic Safety Administration recognizes that a minimal interval between the occurrence of the specified condition and the appearance of the required signal is a physical fact. I enclose a copy of an interpretation of a similar require- ment of Standard No. 105-75 for your information. In the case of the brake fluid level indicator, a time interval that is insignificant with respect to the time required to respond to the signal would be permissible.#Sincerely,Frank A. Berndt,Acting Chief Counsel; |
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ID: aiam0360OpenMr. G.K. Pilz, Product Compliance, Mercedes-Benz of North America, Inc., 158 Linwood Plaza, P.O. Box 318, Fort Lee, New Jersey 07024; Mr. G.K. Pilz Product Compliance Mercedes-Benz of North America Inc. 158 Linwood Plaza P.O. Box 318 Fort Lee New Jersey 07024; Dear Mr. Pilz: #This is in reply to your May 21, 1971, letter to Mr E.H. Wallace to determine whether Dunlop is in compliance as to the use of spaces in the tire identification number. #There are no objections to the spaces between the different parts of the number. However, the photograph illustrates another problem, that of a dual size marked tire. Dual size marked tires are not permissible. The tire can be labeled as one size tire with the indication that t replaces another size tire. For example, 20SR14 replaces ER70-14. #The General Secretary of ETRTO has been advised of the 'dual marked' tire usage. #Sincerely, E.T. Driver, Director, Office of Operating Systems, Motor Vehicle Programs; |
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ID: aiam5498OpenMr. John E. Getz Director, Mobile Products Engineering Ellis & Watts 4400 Glen Willow Lake Lane Batavia, Ohio 45103; Mr. John E. Getz Director Mobile Products Engineering Ellis & Watts 4400 Glen Willow Lake Lane Batavia Ohio 45103; "Dear Mr. Getz: This responds to your letter asking whether certai operations that your company performs on used trailers result in the trailers being considered 'newly manufactured' for purposes of the Federal motor vehicle safety standards. You stated that you sometimes change the finishing and equipment of a used trailer for a new application. As an example, you stated that you recently took a 10- year old trailer, stripped the inside, and refinished it as a mobile marketing facility. You also stated that in some cases you may cut a hole in the side and install a door for a specific application. In a telephone conversation with Dorothy Nakama of my staff, you indicated that you have also changed trailers by adding heating or air conditioning units, or making the trailer usable as an auditorium. In your letter, you asked whether the trailers would be considered 'newly manufactured' if the running gear, VIN and the basic trailer structure do not change, but the ownership does change. You asked this question in light of the fact that change of ownership is relevant under 49 CFR part 571.7(f) in determining whether a trailer manufactured from new and used components is considered newly manufactured. As discussed below, it is our opinion that the operations you describe do not result in the trailers being considered newly manufactured. By way of background information, the National Highway Traffic Safety Administration issues safety standards for new motor vehicles and new motor vehicle equipment. The agency does not provide approvals of motor vehicles or motor vehicle equipment. Instead, manufacturers are required to certify that their vehicles or equipment meet all applicable standards. The following represents our opinion based on the facts provided in your letter. Section 49 CFR part 571.7(f) reads as follows: Combining new and used components in trailer manufacture. When new materials are used in the assembly of a trailer, the trailer will be considered newly manufactured for purposes of the safety standards , unless, at a minimum, the running gear assembly (axle(s), wheels, braking and suspension) is not new, and was taken from an existing trailer-- (1) Whose identity is continued in the reassembled vehicle with respect to the Vehicle Identification Number, and (2) That is owned or leased by the user of the reassembled vehicle. This section only applies when new and used materials are used in the 'assembly' of a trailer. It is our opinion that the operations that you describe, i.e., where the running gear, VIN and the basic trailer structure do not change, do not constitute trailer assembly. Therefore, this section, including its provision concerning transfer of ownership, does not apply. We consider your operations to be in the nature of repair or refurbishment of a used trailer, which does not result in the trailer being considered newly manufactured. I hope this information is helpful. If there are any questions, please contact Dorothy Nakama of my staff at this address or at (202) 366-2992. Sincerely, Philip R. Recht Chief Counsel"; |
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ID: aiam5532OpenMr. Charles Tucker 201 Lakeside Drive, Apt. #48 New Concord, OH 43762-1168; Mr. Charles Tucker 201 Lakeside Drive Apt. #48 New Concord OH 43762-1168; "Dear Mr. Tucker: This responds to your letter of March 21, 1995 requesting a letter stating that your van can be modified by replacing 'the factory installed steering wheel with the smaller ASTECH steering wheel without an air bag.' Your letter explains that your range-of-motion is limited from multiple sclerosis and that the smaller steering wheel improves your ability to drive. During a March 31, 1995 phone call with Mary Versailles of my staff you explained that the van is also equipped with a wheelchair lift and that the floor of the vehicle has been lowered. As explained in this letter, replacement of your steering wheel is permitted provided that a lap/shoulder safety belt is installed at the driver's position. By way of background, the National Highway Traffic Safety Administration is authorized to issue Federal Motor Vehicle Safety Standards that set performance requirements for new motor vehicles and items of motor vehicle equipment. Manufacturers are required to certify that their products conform to all applicable safety standards before they can be offered for sale. If a certified vehicle is modified, other than by the addition, substitution, or removal of readily attachable components, prior to its first retail sale, the person making the modification is an alterer and is required to certify that, as altered the vehicle continues to conform to all applicable safety standards. After the first retail sale, there is one limit on modifications made to vehicles. Manufacturers, distributors, dealers, and repair businesses are prohibited from 'knowingly making inoperative' any device or element of design installed on or in a motor vehicle in compliance with an applicable safety standard. In general, the 'make inoperative' prohibition would require a business which modifies motor vehicles to ensure that they do not remove, disconnect, or degrade the performance of safety equipment installed in compliance with an applicable safety standard. NHTSA has exercised its authority to issue Standard No. 208, Occupant Crash Protection. Standard No. 208 requires light trucks and vans manufactured on or after September 1, 1991 to be capable of providing occupant crash protection to front seat occupants when the vehicle is crash tested at 30 miles per hour (mph) into a concrete barrier. A vehicle that provides this crash protection will increase the safety of vehicle occupants. The air bag installed in your van is one means of complying with this requirement. As a result of this new requirement, this agency received a number of phone calls and letters, from both van converters and individuals like yourself, suggesting that the new light truck and van crash testing requirement will, in effect, prohibit van converters from modifying vehicles to accommodate the special needs of persons in wheelchairs. The agency also received a petition asking for an amendment to the light truck and van crash test requirement in Standard No. 208 to address this problem. As a result on that petition, on March 2, 1993, this agency amended Standard No. 208 to allow manufacturers of light trucks and vans an alternative to complying with the existing requirement. Under the amendment, 'vehicles manufactured for operation by persons with disabilities' are excluded from the light truck and van automatic crash protection requirement. Instead, these vehicles must be equipped with a Type 2 manual belt (integrated lap and shoulder belt) or Type 2A manual belt (non-integrated lap and shoulder belt) at the front outboard seating positions. A 'vehicle manufactured for operation by persons with disabilities' is defined as vehicles that incorporate a level change device (e.g., a wheelchair lift or a ramp) for onloading or offloading an occupant in a wheelchair, an interior element of design intended to provide the vertical clearance necessary to permit a person in a wheelchair to move between the lift or ramp and the driver's position or to occupy that position, and either an adaptive control or special driver seating accommodation to enable persons who have limited use of their arms or legs to operate a vehicle. For purposes of this definition, special driver seating accommodations include a driver's seat easily removable with means installed for that purpose or with simple tools, or a driver's seat with extended adjustment capability to allow a person to easily transfer from a wheelchair to the driver's seat. Based on the information you provided, your van would come within this definition. Therefore, if the modifier of your van would be considered an alterer, it may certify that, with the air bag removed, the vehicle continues to conform to all applicable safety standards, provided that the safety belts are not removed. If the modification is done after the first retail sale, removal of the air bag would not violate the 'make inoperative' prohibition, provided that the safety belts are not removed. I hope this information has been helpful. I have also forwarded a copy of this letter to the modifier indicated in your letter. If you have other questions or need some additional information, please contact Mary Versailles at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel cc: Fitzpatrick Enterprises Attn: Steve Manson FAX 614/497-1863"; |
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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.