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: aiam3796OpenJohn H. Schmidt, P.E., Certification Supervisor, Harley- Davidson Motor Co., Inc., 3700 W. Juneau Avenue, P.O. Box 653, Milwaukee, WI 53201; John H. Schmidt P.E. Certification Supervisor Harley- Davidson Motor Co. Inc. 3700 W. Juneau Avenue P.O. Box 653 Milwaukee WI 53201; Dear Mr. Schmidt: This responds to your February 6, 1984 letter to Roger Fairchild o this office, in which you asked whether your company may include on vehicle certification labels gross vehicle weight rating and gross axle weight rating information expressed in kilograms. The metric units would be used in addition to information expressed in pounds, with the English units appearing first on the label and the metric units following in parenthesis. Our certification regulations (49 CFR Part 567) provide that this information is to be specified in pounds.; The inclusion of metric weight ratings in addition to the English unit specified in our regulation (with the English units appearing first) has previously been approved in an agency interpretation letter, a copy of which is enclosed. Therefore, your proposed certification labels are authorized under the certification regulations.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4053OpenMr. D. Moens, Sales Engineer, Van Hool N.V., Bernard Van Hoolstraat 58, B-2578 Lier, Koningshooikt, Belgium; Mr. D. Moens Sales Engineer Van Hool N.V. Bernard Van Hoolstraat 58 B-2578 Lier Koningshooikt Belgium; Dear Mr. Moens: This responds to your October 10, 1985 letter to this agency requestin an interpretation of Federal Motor Vehicle Safety Standard (FMVSS) No. 217, *Bus Window Retention and Release*. You asked whether FMVSS No. 217 allows the use of sliding roof emergency exits. The answer to your question depends on the location of the release mechanism and the direction in which the mechanism operates relative to the surface of the closed exit. As explained below, if the release mechanism falls in the area of high force application, i.e., the area of the bus in which high operating forces may be used, then the answer to your question is no.; According to your letter, you provide two roof hatches on your buses in the front and rear of the vehicles, although the front roof hatch is not needed to meet the unobstructed openings requirement of Standard No. 217. The roof hatches would slide open rather than push out, and would be opened by a handle which is located in the region of high force application as shown in Figure 3B of the standard.; Standard No. 217 requires buses to be equipped with emergency exits an specifies requirements that all emergency exits must meet. Paragraph S5.2.1 of Standard No. 217 provides that a roof exit may be installed on buses with gross vehicle weight ratings of more than 10,000 pounds when the bus configuration precludes installation of an accessible rear exit. The roof exit must meet the requirements of paragraphs S5.3 through S5.5. Under S5.3.2, the direction of required force application in the high force access region is straight and perpendicular to the exit surface. Since your exit is designed so that the force is applied parallel to the exit surface, it does not comply with S5.3.2.; Of course, your roof emergency exit must meet all applicabl requirements in FMVSS No. 217. You should note that under S5.3.1, a roof exit must provide for a release mechanism, located within the regions depicted in Figure 3B of the standard. The release mechanism must be operated by one or two force applications which comply with S5.3.2. Further S5.5 sets certain identification requirements for roof emergency exits.; You stated that the roof exit installed in the forward half of the bu does not need to be counted to satisfy the unobstructed openings requirement of Standard No. 217. Exits that are not labeled or intended as emergency exits need not meet the emergency exit requirements of FMVSS No. 217.; You asked what consequences would follow if we determine that you sliding roof exit does not comply with FMVSS No. 217. That standard was issued under the National Traffic and Motor Vehicle Safety Act. The Act requires manufacturers to comply with all applicable safety standards. It also requires them to notify purchasers of their motor vehicles of safety- related defects and failures to comply with the safety standards, and to remedy such defects and noncompliances without charge. Violations of the Act's requirements are punishable by civil fines of up to $1,000 per violation, with a maximum $800,000 for a related series of violations. Under the regulations set forth in Part 556 of Title 49 of the Code of Federal Regulations (copy enclosed), manufacturers may petition NHTSA for an exemption from the Act's notice and remedy requirements if they believe that the defect or noncompliance is inconsequential as it relates to motor vehicle safety. However, if the agency denies such a petition, *all* duties relating to notice and remedy of the defect or noncompliance contained in the Vehicle Safety Act are continued in force against the manufacturer.; Mr. Sebastian Messina of the New Jersey Department of Transportatio has contacted us concerning the sliding emergency exits on your buses. We are sending him a copy of this letter for his information.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam2884OpenHarry A. Carson, McClintock Donovan Carson & Roach, Gardian Building, Detroit, MI 48226; Harry A. Carson McClintock Donovan Carson & Roach Gardian Building Detroit MI 48226; Dear Mr. Carson: This is in response to your letter of September 1, 1978, requestin information on the Federal odometer disclosure requirements. You specifically asked what a lessor's responsibility is with regard to the certifications on the disclosure statement. The lessor, as transferor of a vehicle, is required to certify, to the best of his knowledge, as to the accuracy of the vehicle's odometer. A lessor should assume that an odometer is accurate unless he has reason to believe otherwise. Any reasonable belief that the odometer is wrong should be reflected on the disclosure statement by checking, in the first set of certifications, either box 2 or 3, as appropriate. In situations where the lessor has no knowledge as to the accuracy of the odometer reading, he should *not* state that the mileage is in error because to the best of his knowledge it is correct.; With regard to the second set of certifications, the lessor shoul check box 1 unless he altered or knows that the lessee or some other person altered the odometer. Since your client is concerned about the possibility that the lessee may alter the odometer, he may find it advisable to protect himself by requiring the lessee to indemnify him in the event of liability under the Motor Vehicle Information and Cost Savings Act. He may also add a statement on the disclosure form that the vehicle was subject to a lease or was otherwise outside of his control.; Sincerely, John Womack, Assistant Chief Counsel |
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ID: aiam1251OpenMr. James Tydings, Chief Engineer, Thomas Built Buses, Inc., 1408 Courtesy Road, P.O. 1849, High Point, NC 27261; Mr. James Tydings Chief Engineer Thomas Built Buses Inc. 1408 Courtesy Road P.O. 1849 High Point NC 27261; Dear Mr. Tydings: This is in reply to your letters of July 26 and August 7, 1973 requesting an opinion on the applicability of the emergency exit provisions (S5.3 to S5.5) of Motor Vehicle Safety Standard No.217, Bus Window Retention and Release (49 CFR 571.217), to buses that are of the same design as school buses, but which are not manufactuerd (sic) (they are not painted yellow, nor do they have warning devices) nor used as school buses. You ask further that the standard exempt prison buses.; We interpret the exemption for school buses to include buses similarl designed, without regard to their intended use. School bus is defined in 49 CFR 571.3 to mean,; a bus *designed* primarily to carry children to and from school....' We are of the opinion that buses which share the same design as buse that clearly fall within the definition of school bus' are school buses under Standard No. 217, and are therefore exempt from the emergency exit provisions of the standard. No modification of the standard is accordingly called for.; With respect to your request regarding prison buses, we are presentl considering similar requests previously received, and plan to respond by notice published in the *Federal Register* in the near future.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4403OpenMr. Frederic M. Petler, Head, Administration, Government Relations Department, American Suzuki Motor Corporation, P.O. Box 1100, 3251 East Imperial Highway, Brea, CA 92622-1100; Mr. Frederic M. Petler Head Administration Government Relations Department American Suzuki Motor Corporation P.O. Box 1100 3251 East Imperial Highway Brea CA 92622-1100; Dear Mr. Petler: This letter responds to your letter of June 12, 1987, stating that you company wishes to add the following additional language to the Part 567 certification label:; >>>'This vehicle equipped for 800 lb./360 kg payload. See owner' manual for additional information.'<<<; You further state your understanding that NHTSA has permitte manufacturers to put information on the certification label beyond what Part 567 requires. You include two samples ('A' and 'B') representing certification labels, showing alternative locations on the label for your statement. The sample you designate as 'A' shows your statement just above the required vehicle identification number, and just below the statement that your vehicle complies with all applicable Federal motor vehicle safety standards. The sample you designate as 'B' shows your statement just below all of the information S567.4 requires a manufacturer to put on the certification label. You ask which sample the agency would find acceptable.; You are correct that the agency has permitted manufacturers to includ information on the certification label beyond that which Part 567 requires. Where NHTSA has acquiesced in this practice, the additional information appeared after that required under S567.4(g). Sample B shows the placement of your additional statement after the required Part 567 information. NHTSA finds that Sample B is acceptable so long as your label otherwise complies with Part 567.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1601OpenMr. M. J. Denholm, Director of Engineering, Power Controls Division, Midland-Ross Corporation, 490 So. Chestnut Street, Owosso, MI 48867; Mr. M. J. Denholm Director of Engineering Power Controls Division Midland-Ross Corporation 490 So. Chestnut Street Owosso MI 48867; Dear Mr. Denholm: This responds to Midland-Ross' February 8, 1974, petition for a amendment of S5.1.2.1 and S5.2.1.2 of Standard No. 121, *Air brake systems*, to establish separate air reservoir volume requirements for several brake chamber types generally available in the air brake component market.; The standard presently requires air reservoir volumes to be a multipl of the vehicle's brake chamber volumes. Midland-Ross also requested that S5.1.2.2 and S5.2.1.3 be amended to require that a reservoir withstand hydrostatic pressure five times greater than stated on its label without rupture, or permanent circumferential deformation exceeding one percent. The standard presently requires that an air reservoir withstand internal hydrostatic pressure of five times the vehicle compressor cutout pressure or 500 pounds, whichever is greater. The petition also requests modifications of the trailer test rig, which were made in a recent amendment of the standard (29 FR 17563, May 17, 1974).; You suggested that our requirement for air reservoir volume as multiple of brake chamber volume will encourage installation of smaller equipment and thereby create a safety problem. We cannot agree, in view of the standard's stopping distance requirements which in effect mandate the installation of high performance components. Indications to date are that manufacturers have in fact not reduced brake chamber volumes. A certain degree of chamber stroke standardization may occur, which the NHTSA views as favorable. For these reasons your request is denied.; With regard to the air reservoir pressure requirements of S5.1.2.2 an S5.2.1.3, you argued that a reservoir manufacturer is unable to establish the required strength of his product because he cannot control the compressor cutout pressure of the vehicle on which the reservoir is installed. It should be understood that the standard is not an equipment standard with which Midland-Ross must comply, but a vehicle standard with which the vehicle manufacturer must comply. We have determined that the reservoir should be designed to manage the pressures to which it might be exposed on the vehicle on which it is installed. The vehicle manufacturer is able to establish a compressor cutout pressure (on powered vehicles) and, based on that value, order the appropriate reservoir to meet the requirement. It is evident that commercial considerations will standardize compressor cutout pressures on a reasonable range of available reservoir strengths. Midland-Ross as a manufacturer of reservoirs is free to establish a range of reservoir strengths, and label the reservoirs as described in your petition. For the reasons cited, however, your petition to mandate this is denied.; We agree the requirement that a reservoir 'withstand' a certai pressure can be further specified, and we are considering a proposal to do this in the future. At this time the NHTSA has adopted the SAE Standard No. J10a, which specifies that there be no rupture or permanent circumferential deformation exceeding one percent.; Sincerely, James B. Gregory, Administrator |
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ID: aiam0913OpenMr. Gorou Utsunomiya, Branch Manager, Toyo Kogyo USA Rep. Ofc. Det. Branch, 23777 Greenfield Rd., Suite 462, Southfield, MI 48075; Mr. Gorou Utsunomiya Branch Manager Toyo Kogyo USA Rep. Ofc. Det. Branch 23777 Greenfield Rd. Suite 462 Southfield MI 48075; Dear Mr. Utsunomiya:#This is in reply to your letter of October 13 1972, asking a question concerning the location of the identification of the fan control as proposed by Docket No. 1-18, Notice 7. Under the system discussed in your letter, the word 'FAN' would be located on the control panel and illuminated. An additional 'FAN' would appear on the control itself but would not be illuminated.#The NHTSA proposal would require identification of the 'fan control' with the word 'FAN', and that this identification be illuminated. Paragraph S4.2.1 of Standard No. 101 requires that identification be placed on or adjacent to the control. The control panel of your system appears adjacent to the control, and where identification is placed both on and adjacent to the control, illumination of either will meet the proposed requirements.#Yours truly, Richard B. Dyson, Assistant Chief Counsel; |
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ID: aiam1314OpenMr. Rudolfo H. Schroeter, Suite 2600 Equitable Plaza, 3435 Wilshire Boulevard, Los Angeles, California 90010; Mr. Rudolfo H. Schroeter Suite 2600 Equitable Plaza 3435 Wilshire Boulevard Los Angeles California 90010; Dear Mr. Schroeter: This is in reply to you letter of October 24, 1973, in which you as the following questions:; 1. Is it true that Standard Nos. 109 and 110 are not applicable to 1/2-ton pickup truck with camper because such vehicle is not a 'passenger car' as defined in Standards 109 and 110?; 2. Is it true that in Appendix A of Standard 110 no 'alternative rims are listed for the L70-15 tire simply because no one has requested (in the manner provided in Appendix A to Standard 110) inclusion of such additional or alternative rim widths.; With respect to question 1, a pickup truck is not a passenger car but 'truck' (as defined in 49 CFR S571.3) for purposes of all the Federal motor vehicle safety standards, including Standard Nos. 109 and 110. Standard No. 110 (49 CFR S571.110) applies only to passenger cars, not to pickup trucks.; In response to your second question, the answer is not an unequivoca 'yes', and I regret that you may have drawn that conclusion from your conversation with Michael Peskoe of this office. In order for alternative rims to be listed with a tire size designation in the Appendix of Standard No. 110, data showing that the tire and rim combination meets the requirements of both Standard No. 109 and 110 must first be submitted to the agency. Once that data has been provided, the NHTSA will publish the alternative rim size in Standard No. 110, and if no objections are received within a 30-day period, the tire/rim combination becomes part of the standard. Thus, there are not one but two possible reasons way a rim size is not listed in Standard No. 110:; >>>The tire/rim combination fails to meet either Standard No. 109 o 110, or; It does meet both standards, but no one has requested approval of th combination. This could occur simply if the combination was not intended to be used as original equipment on a passenger car.<<<; Sincerely, Lawrence, R. Schneider, Chief Counsel |
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ID: aiam3329OpenMr. Kenneth W. Rix, Vice President, Great Plains Industries, Inc., 1711 Longfellow Lane, Wichita, KS 67207; Mr. Kenneth W. Rix Vice President Great Plains Industries Inc. 1711 Longfellow Lane Wichita KS 67207; Dear Mr. Rix: This responds to your letter of July 31, 1980, concerning a evaporative cooler you are considering manufacturing for use on motor vehicles. You explained that the unit would mount just outside the upper portion of the passenger window and would block approximately the upper 3 1/2 inches and protrude to the right of the drip rail approximately 10 inches. The following discussion answers your questions and outlines your responsibilities under the National Traffic and Motor Vehicle Safety Act (The Act, 15 U.S.C. 1381 *et seq*., a copy of which is enclosed).; You first asked whether your evaporative cooler would violate an Federal safety regulations. The agency has not issued and Federal motor vehicle safety standard directly establishing requirements for evaporative coolers. However, as explained below, installation of your cooler may be affected by the agency's proposed standard on direct fields of view. That proposal would prohibit certain obstructions in the driver's field of view. I have enclosed a copy of that notice of proposed rulemaking. (The agency does not plan to take final action on this proposal until early next year.); If the field of direct view standard is adopted, then installation o an evaporative cooler in a new vehicle prior to the vehicle's sale to the first purchaser could be affected by section 108(a)(1)(C) of the Act, and the agency's certification regulation (49 CFR 567, a copy of which is enclosed). If a cooler is installed as an add-on item of motor vehicle equipment by a vehicle dealer prior to the vehicle's delivery to the first purchaser, then section 567.7 of the certification regulation would apply. That section provides that a person who alters a previously certified vehicle prior to its first purchase must certify that the vehicle, as altered, still conforms to all applicable standards. Thus, a new vehicle would have to comply with the fields of view requirements with the cooler installed.; Whether or not your cooler is covered by a Federal safety standard, a a manufacturer of motor vehicle equipment you are required to comply with the provisions of the Act pertaining to safety-related defects (sections 151-159, 15 U.S.C. 1411-1419). Thus, if your company learns of a defect relating to motor vehicle safety in its evaporative coolers, you would be required to notify this agency, as well as owners, purchasers or dealers of the equipment, concerning the defect and to remedy the defect without charge. Parts 573, 576, 577 and 579 of the agency's regulations (49 CFR 573, 576, 577 and 579) define in detail a manufacturer's responsibilities with regard to safety-related defects. I have enclosed copies of those regulations.; You also asked whether you must check each state code prior to sale o your evaporative cooler in that state, since some states may have regulations that are more restrictive than the Federal regulations. In the absence of a Federal standard directly affecting evaporative coolers, state regulations would govern the sale of your cooler. If there was a Federal standard affecting the installation of your cooler, then the Federal regulation may preempt conflicting State regulations. Section 103(d) of the Act provides that no State may have a standard 'applicable to the same aspect of performance' of a motor vehicle or item of motor vehicle equipment, unless the state standard is 'identical to the Federal standard.' The Act does authorize State (sic) to establish higher standards of performance than the applicable Federal standard for vehicles or equipment procured for its own use. A determination of whether a Federal standard on direct fields of view would preempt a state standard on the same subject can only be made on a case-by-case basis after final action is taken on the field of view proposal and after reviewing the particular State standard.; You also asked whether you could use certain statements on your coole advising people to check state regulations before installing the cooler. The validity of such statements would be regulated by state law. Finally, you asked how you could obtain copies of state vehicle codes and information about obtaining a wavier (sic) or amendment of such codes. A law library may have copies of such codes. Otherwise, you will probably have to write to each State agency regulating motor vehicles to obtain a copy of their codes. I hope this information is of help to you. Please contact Steve Oesch of my office if you have any further questions about Federal regulations affecting your product at (202-426- 2992).; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4116OpenMr. A. D. Fish, Road Transport Division, Ministry of Transportation, Aurora House, 62 The Terrace, Wellington, New Zealand; Mr. A. D. Fish Road Transport Division Ministry of Transportation Aurora House 62 The Terrace Wellington New Zealand; Dear Mr. Fish: We regret the delay in responding to your letter (14/1/9) date September 18, 1985, to Mr. Francis Armstrong requesting information in relation to our compliance test report number 213-CAL-83-011. Your letter was referred to my office.; In your letter you asked for an interpretation of Standard No. 213 *Child Restraint Systems*, regarding the reason for the test laboratory marking two parts of the test procedure as not applicable to your child restraint. The two answers to your specific questions are as follows:; 1. Page 12--*Resistance to Microorganisms*. Polyester and nylon, whic comprise 100% of all vehicle seat belt and child seat harness webbing, are inherently resistant to microorganisms. Therefore, in an exercise of its prosecutorial discretion, the agency has thus far chosen not to conduct this test on nylon and polyester belts. If a child restraint harness or vehicle seat belt were found to be made of cotton or some other fibrous material, the resistance to microorganisms test would be conducted on those materials. In addition, the agency reserves the authority to test nylon and polyester belts as well, although it has no plans to do so.; 2. Page 26--S5.4.3.3. *Seating Systems*. The requirements of S5.4.3. apply to child restraints that are 'designed for use by a child in a seated position.' Infant restraints are designed to place the child in a rear-facing, semi-recumbent position instead of a seated position and therefore S5.4.3.3 is not applicable to them. Since infant restraints are rear-facing, the major forces acting on the child's body from vehicle deceleration are exerted by the foam liner/plastic shell instead of the belt system. In addition, all infant restraints on the market are equipped with a three-point harness (shoulder belt/crotch strap) to position the child and hold him or her in the restraint during rebound.; Sincerely, Erika Z. Jones, 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.