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: aiam3764OpenJohn Bertman, Esq., Bertman, Johnson and Sahli, 401 Twelfth Street (Route #54), P.O. Box 440, Hammonton, NJ 08037-0440; John Bertman Esq. Bertman Johnson and Sahli 401 Twelfth Street (Route #54) P.O. Box 440 Hammonton NJ 08037-0440; Dear Mr. Bertman: This responds to your recent letter to this office, seeking informatio on retreaded passenger car tires. You asked for the name of the retreader of a tire with the code letters 'BJE' marked on the sidewall. That retreader is Trio Tire Service, Inc. of Clementon, New Jersey. You also asked if there were any regulations applicable to the retread of radial tires. All retreaded passenger car tires (whether bias or radial) must be certified by the retreader as complying with the requirements of Federal Motor Vehicle Safety Standard No. 117 (49 CFR S 571.117). I have enclosed a copy of the standard for your information.; Should you have any further questions or need further information i this area, please contact Mr. Stephen Kratzke of my staff at this address and at (202) 426- 2992.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1036OpenMr. Sanford Davis, Corporate Flammability Coordinator, BASF Wyandotte Corporation, Wyandotte, MI, 48192; Mr. Sanford Davis Corporate Flammability Coordinator BASF Wyandotte Corporation Wyandotte MI 48192; Dear Mr. Davis: This is in reply to your letter of February 20, 1973, asking for a interpretation of the self-extinguishing test in the burn- rate requirement of Paragraph S4.3 of Motor Vehicle Safety Standard No. 302, 'Flammability of Interior Materials'. You ask whether both the 60- second as well as the 2-inch criterion must be satisfied in order to meet this self-extinguishing test. The answer to your question is yes. Both criteria must be met before any material shall be considered to have satisfied the burn-rate requirement.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4234OpenDennis H. Oyakawa, Esq., Graham & James, 725 South Figueroa Street, Los Angeles, CA 90017-5434; Dennis H. Oyakawa Esq. Graham & James 725 South Figueroa Street Los Angeles CA 90017-5434; Dear Mr. Oyakawa: Thank you for your letter of September 16, 1986, to Stephen Oesch of m staff concerning how the National Traffic and Motor Vehicle Safety Act and our regulations affect the proposed manufacture and sale of aftermarket safety belts by your client. As discussed below, your proposed plan would not violate either the Vehicle Safety Act or our regulations.; You explained that your client has supplied safety belts to a vehicl manufacturer for use both as an item of original equipment in a new vehicle and as item of replacement equipment for sale in the aftermarket. You said your client has recently been requested by the vehicle manufacturer to supply safety belts to be used as a replacement part for an older model vehicle which was exported to and marketed in the United States over 10 years age. You further explained that your client manufactured the original safety belts used in this older model vehicle, but is no longer equipped to readily manufacture the original safety belts.; Your client wishes to supply the vehicle manufacturer with a newe model safety belt. This newer safety belt has been designed to be installed as a replacement part in the older model vehicle and will fully comply with all of the requirements of Standard No. 209, *Seat Belt Assemblies*. In addition, the safety belt is also designed so that when it is installed in a vehicle, the vehicle will continue to comply with all of the applicable requirements of Standard Nos. 208, *Occupant Crash Protection*, and 210, *Seat Belt Assembly Anchorages*. Finally, you said that the newer model safety belt will not render inoperative any other features of the vehicle necessary to meet any other applicable safety standards.; As you are already aware, your client's proposed safety belt would b required to comply with Standard No. 209. As you are also aware, installation of your client's safety belt by a manufacturer, distributor, dealer, or motor vehicle repair shop would be affected by the render inoperative provision of section 108(a)(2)(A) of the Vehicle Safety Act. However, as stated in your letter, your client has determined that installation of the belt will not render inoperative any other safety features of the vehicle. There is another 108(a)(2)(A) related issue raised by your letter. This concerns whether an item of equipment installed in accordance with one version of a Federal motor vehicle safety standard can be replaced with an item of equipment that complies with a later version of that standard. The agency addressed this issue in a letter of July 7, 1975 to Toyo Kogyo Co., Ltd. In that letter, the agency explained that it would not be a violation of section 108 as long as the vehicle or equipment complies with the safety standards in effect at the time of its manufacture or with the standards in effect at the time a particular system is replaced or altered, even if the new standards set less stringent performance requirements.; If you have any further questions, please let me know. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1466OpenMr. Earl V. Gordon, Manager of Engineering, The Adams & Westlake Company, 1025 North Michigan Street, Elkhart, IN 46514; Mr. Earl V. Gordon Manager of Engineering The Adams & Westlake Company 1025 North Michigan Street Elkhart IN 46514; Dear Mr. Gordon: This is in reply to your letter of March 13, 1974, asking whethe S5.3.2. of Motor Vehicle Safety Standard No. 217, Bus Window Retention and Release,' permits the use of more than one release mechanism on any one opening if each mechanism requires a separate motion to release.; Standard No. 217 does not prohibit the use of more than one separat release mechanism for a single opening. However, S5.3.2 does limit to two the number of total force applications, and this limits the number of separate release mechanisms to two. If two release mechanisms are used, each must be operated by only one force application, and one of these force applications must differ by 90 degrees to 180 degrees from the direction of the initial push-out motion of the emergency exit.; Of course, in using this configuration, the other requirement pertaining to emergency exits and release mechanisms in Standard No. 217 must also be met.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4664OpenMr. Stephen R. Darling Presvac Systems (Burlington) Ltd. 4131 Morris Drive Burlington, Ontario, Canada L7L 5L5; Mr. Stephen R. Darling Presvac Systems (Burlington) Ltd. 4131 Morris Drive Burlington Ontario Canada L7L 5L5; "Dear Mr. Darling: This responds to your inquiry about an amendment t 49 CFR Part 575, Consumer Information Regulations, requiring vehicle manufacturers to include information in the owner's manual (or on a one-page document if there is no owner's manual) about the National Highway Traffic Safety Administration's Auto Safety Hotline and its defect investigation and remedy and recall authority. (54 FR 48745, November 27, 1989, copy enclosed). I apologize for the delay in our response. You explained that you are involved in three types of activities: the manufacture of liquid cargo vessel trailers, the fabrication of liquid cargo tanks, and the installation of these tanks onto existing or modified truck chassis. While you acknowledged your obligation to furnish the consumer information for the trailers you manufacture, you were uncertain about your responsibilities to furnish this information for the liquid cargo tanks you fabricate and install. You asked whether you are required to supply the specified consumer information in these instances. Your questions are responded to below. Section 575.6(a)(2)(i), as amended, provides that 'At the time a motor vehicle manufactured on or after September 1, 1990 is delivered to the first purchaser for purposes other than resale, the manufacturer shall provide to the purchaser' a specified statement about this agency's activities related to motor vehicle defects. Among other things, the specified statement indicates that if an owner believes the vehicle has a defect which could cause a crash or an injury or death, the owner should inform NHTSA in addition to notifying the manufacturer. The manufacturer's name must be indicated in the statement. In responding to your questions, I note that section 575.6(a)(2)(i) applies to manufacturers of new motor vehicles. As a manufacturer of trailers, you are, of course, responsible for providing the specified consumer information to the first purchaser of such trailers (for purposes other than resale). On the other hand, in situations where you are not a vehicle manufacturer, e.g., where you may be installing tanks on used motor vehicles, the requirements would not apply. Your letter also raises the issue of how section 575.6(a)(2)(i) applies in situations where there is more than one manufacturer of a motor vehicle, i.e., where vehicles are manufactured in two or more stages. While it is not clear from your letter, it is possible that you may be a final stage manufacturer under 49 CFR Part 568. (The term 'final stage manufacturer' is defined in 49 CFR Part 568.3.) As indicated above, section 575.6(a)(2)(i) specifies that, at the time a vehicle is delivered to the first purchaser for purposes other than resale, 'the manufacturer' must provide specified consumer information to the purchaser. Since the regulation requires information to be provided at the time of first consumer sale, we construe it to require the manufacturer of the completed vehicle, i.e., the final stage manufacturer, to meet this requirement. As a general rule, the final stage manufacturer is the manufacturer that has the closest relationship to the dealer which sells the vehicle to the consumer. It is also the manufacturer that the consumer will typically contact first in the event of problems. I hope this information is helpful. If you have any further questions, please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel Enclosures"; |
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ID: aiam1935OpenMr. Ernest D. Mathews, Chief, Field Services, Department of Motor Vehicles, Sate of Vermont, Montpelier, VT 05602; Mr. Ernest D. Mathews Chief Field Services Department of Motor Vehicles Sate of Vermont Montpelier VT 05602; Dear Mr. Mathews: This is in reply to your letter of April 17, 1975, to this agenc asking questions about paragraph S4.6(b) of Motor Vehicle Safety Standard No. 108, relating to headlamp flashers. Your reference to S4.5.8(b) is out-dated by approximately three years and I am enclosing a copy of Standard No. 108 as it now exists.; You asked the reason for the section in question, which provides tha 'All other lamps shall be steady- burning, except that means may be provided to flash headlamps and side marker lamps for signaling purposes.' You also asked whether all motor vehicles, including motorcycles, are 'authorized' by this section to use flashing headlamps, and finally whether the standard prohibits States from promulgating regulations to control flashing headlamps.; S4.6(b) was not intended as a regulation of this aspect of moto vehicle performance, in the sense that it would preempt all State regulation of the sale or use of headlamp flashers. It is basically merely an exception to the requirement of Standard 108 that all lamps (other than turn signals, hazard warning signals, and school bus warning signals) be steady-burning. The section, in other words, was included to make it clear that automatic headlamp flashers are not prohibited by the Federal standard. With reference to your questions, this is the only way in which they are 'authorized' by Standard 108.; We have concluded, therefore, that State regulation of headlam flashers is not preempted by the Federal standard.; Sincerely, James C. Schultz, Chief Counsel |
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ID: aiam3908OpenMs. Mildred Roger, Ms. Estelle Friedman, Uncanny Products, 5904 Edinger Avenue, Huntington Beach, CA 92649; Ms. Mildred Roger Ms. Estelle Friedman Uncanny Products 5904 Edinger Avenue Huntington Beach CA 92649; Dear Ms. Roger: This responds to your letter of January 21, 1985, concerning a aftermarket product you manufacture. The product, which you call the 'Uncanny Seat Belt Comfort Control Belt,' consists of a strap which can be fastened around the shoulder and lap webbing of a lap- shoulder safety belt near the buckle. A belt user can then slide the strap along the webbing, thus causing the shoulder portion of the belt to move away from the person's neck and make the belt more comfortable to wear. You asked for the agency to approve, disapprove, or endorse your product so that it can be advertised in certain magazines.; No such agency action is necessary before you advertise your product Further, the agency does not have the authority to approve or endorse items of motor vehicle equipment, such as your device. We do have the authority to issue Federal Motor Vehicle Safety Standards that set performance requirements for motor vehicles and items of motor vehicle equipment. Manufacturers of vehicles or equipment covered by our standards must certify that their product complies with all of the applicable standards.; Your particular aftermarket product is not covered by any of our safet belt or other standards. However, as a manufacturer of an item of motor vehicle equipment, you do have certain responsibilities concerning possible safety-related defects you or the agency discover in your products. Those responsibilities are set out in sections 1411-1420 of the National Traffic and Motor Vehicle Safety Act, a copy of which is enclosed.; The agency is concerned that a belted occupant could use your produc to reduce the effectiveness of the upper torso belt by moving the belt so close to the edge of the shoulder that the occupant could rotate out of the upper torso belt in a crash. Likewise, your product could be used to introduce excessive slack in the upper torso belt, which would also reduce its effectiveness. We urge you to include a warning in your instructions to advise belt users about the proper use of your product.; I am returning the sample of your product that you enclosed with you letter. If you have any further questions, please let me know.; Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam0627OpenMr. T.V. Barlow, Technical Liaison Manager, Wingard Limited, Chichester, Sussex, England; Mr. T.V. Barlow Technical Liaison Manager Wingard Limited Chichester Sussex England; Dear Mr. Barlow: This is in reply to your letter of February 10, 1972, regardin interpretation of certain parts of Federal Motor Vehicle Safety Standard No. 209, Seat Belt Assemblies.; In regard to your question on performance of retractors, the standar specifies that an emergency- locking retractor or a non-locking retractor attached to upper torso restraint shall be subjected to 45,000 additional cycles of webbing withdrawal and retraction between 50 and 100 percent extension.' This requirement applies to all emergency-locking retractors whether attached to the pelvic or upper torso restraint and only to those non-locking retractors that are attached to the upper torso restraint.; In regard to the 45,000 additional cycles, one cycle consists o extending the webbing from 50 to 100 percent extension and return to 50 percent.; Please do not hesitate to contact us if we can be of furthe assistance.; Sincerely, Robert L. Carter, Acting Associate Administrator, Moto Vehicle Programs; |
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ID: aiam5425OpenMs. Doris Hull Owner Sikeston Trailer Sales, Inc. Route 2, Box 2291 Sikeston, MO 63801; Ms. Doris Hull Owner Sikeston Trailer Sales Inc. Route 2 Box 2291 Sikeston MO 63801; Dear Ms. Hull: This responds to your letter of May 16, 1994, addresse to Mr. Robert Hellmuth, whom you identified as Chief Counsel. For your future information, Mr. Hellmuth is Chief of the Office of Vehicle Safety Compliance of this agency. I am the Acting Chief Counsel. Your letter referred to a May 13, 1994 telephone conversation that you and Mr. David McCormick had with Walter Myers of my staff concerning new and used tires on trailers. You asked for confirmation of your understanding of what was said during that conversation, as follows: (a) That as a trailer manufacturer you can sell to a dealer new trailers that are stacked one on top of the other, with new tires on the bottom trailer but no tires or wheels on the stacked trailers, (b) That you can sell used tires and rims but not installed on the new trailers, and (c) That you can separately sell used tires and rims to the purchaser of a trailer, then install them on the new trailer if the purchaser so requests. FMVSS No. 120, Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars (copy enclosed) provides that vehicles equipped with pneumatic tires for highway service shall be equipped with tires that meet the requirements either of FMVSS 109, New Pneumatic Tires, or FMVSS No. 119, New Pneumatic Tires for Other Than Passenger Cars. Both those standards specify requirements for new tires. As an exception to those requirements, however, paragraph S5.1.3 of FMVSS No.120 provides that: A truck, bus, or trailer may at the request of the purchaser be equipped at the place of manufacture of the vehicle with retreaded or used tires owned or leased by the purchaser, . . . Used tires employed under this provision must have been originally manufactured to comply with Standard No. 119, as evidenced by the DOT symbol (emphasis added). With that background in mind, your understanding (a) above is correct. You stated to Mr. Myers that it is common practice in the industry to stack completed trailers one on top of another for shipment, with the bottom trailer being equipped with new tires. This office stated in a letter to Mr. Steve Thomas dated April 14, 1993 (copy enclosed), that new trailers may be sold without tires and wheels. Accordingly, it is permissible to ship trailers without tires and wheels, with new tires on the bottom trailer that is carrying the others. Your understanding (b) is also correct, but with a caveat. No provision of Federal law or regulation prohibits you from separately selling used tires and wheels that you own to anyone you want, including dealers. However, the practice you describe implies that the dealer will be installing the used tires you've provided on the new trailers, which would amount to a violation of Standard No. 120. The standard specifically provides that used or retreaded tires may be installed on new vehicles only at the place of manufacture, the dealer is not permitted to install used tires on new trailers, whether or not owned and requested by the purchaser. Further, a manufacturer that includes used tires with new vehicles, even though not installed on the new vehicle, could be considered to be contributing to a potential violation of the Federal motor vehicle safety standards by the dealer. With respect to understanding (c), S5.1.3, as noted above, requires that used or retreaded tires installed on a new vehicle be owned or leased by the purchaser of the vehicle. The standard, however, does not specify any length of time that the used or retreaded tires must be owned or leased by the vehicle purchaser, nor does the standard specify the source(s) from which the purchaser must have acquired the used or retreaded tires. Therefore, there is no prohibition against the purchaser of a trailer purchasing used or retreaded tires from a trailer manufacturer or from any other source, then requesting the manufacturer to install them on the new trailer. However, we have the following observations about the practice. The used/retreaded tire exception in S5.1.3 was included in the standard to accommodate bus and truck fleets who either purchase or lease tires on a mileage contract basis or who maintain tire banks. A mileage contract purchaser or lessor is one who purchases or leases tires on a per-mile basis. A tire bank is composed of serviceable tires that have been removed from vehicles no longer in service. Mileage contract purchases and tire banks are standard practices in the transportation industry and the agency assumed that those purchasers would select only safe, serviceable tires from their inventories for installation on their new vehicles. The agency also assumed that those purchasers would have owned and used those tires for some length of time prior to their being selected for installation on new vehicles. Thus, the practice of a new vehicle purchaser purchasing used tires from a trailer manufacturer and then asking the manufacturer to install them on the new vehicle was not envisioned by this agency when issuing Standard No. 120. None of the above would relieve trailer manufacturers from their responsibility to attach the required labels with the recommended tire and rim sizes and inflation pressures in accordance with 49 CFR Part 567. I hope this information is helpful to you. Should you have any further questions or need additional information, please feel free to contact Mr. Myers at this address or at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosure; |
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ID: aiam0277OpenMr. Donald Mallett, Jeep Corporation, 940 North Cove Boulevard, P.O. Box 903, Toledo, OH 43601; Mr. Donald Mallett Jeep Corporation 940 North Cove Boulevard P.O. Box 903 Toledo OH 43601; Dear Mr. Mallett: On June 16, 1971, you and Mr. William Fleming of American Motors me with representatives of NHTSA and pointed out that the March 4, 1971, revisions of Standard No. 210 (36 F.R. 4291) had created a situation where seat belt anchorages for side-facing seats of multipurpose passenger vehicles would have to meet strength requirements only for the six-month period from July 1, 1971, to January 1, 1972. This occurred because the March 4 notice, which basically extended the existing standard for passenger cars to other types of vehicles as of July 1, 1972, did not have the exemption for side-facing seat belt anchorages that is contained in the revised standard that goes into effect on January 1, 1972.; The failure to exempt side-facing seats from the anchorage tes requirements for the six-month period ending January 1, 1972, was inadvertent. A *Federal Register* notice will be issued shortly amending Standard No. 210 to correct this discrepancy. I am sending you this letter, which will be placed in the public files, in advance of the notice as an extraordinary procedure in light of the time period involved, to confirm that your vehicles need not meet the strength requirements for seat belt anchorages for side-facing seats apparently contained in Standard No. 210.; Sincerely, Robert L. Carter, Acting Associate Administrator, Moto Vehicle Programs; |
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.