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: aiam4130OpenRobert Bosch GmbH, Postfach 50, 7000 Stuttgart 1, Germany, Attention: Herr Berg; Robert Bosch GmbH Postfach 50 7000 Stuttgart 1 Germany Attention: Herr Berg; Gentlemen: This is in response to a letter from Robert Bosch GmbH dated March 13 1986, with reference to 'Approval for exemption from Humidity test S6.8' of Federal Motor Vehicle Safety Standard No. 108.; You have asked that vented replaceable bulb headlamps produced b Robert Bosch be exempted from compliance with paragraph S6.8 of Standard No. 108 on the grounds that failure to comply would be inconsequential noncompliance. You request that this exemption continue until such time as S6.8 is modified, presumably in accordance with the petition for its amendment which you filed in October 1985. The purpose of your request is to allow you 'to test headlamps with ventilation openings pursuant to the procedure described on page 4' of your petition, and in the event that that test is successful 'we request authority to use the headlamps in motor vehicles.'; I should like to explain briefly our exemption authority because we ca not consider your request. You have asked us to excuse prospective conduct that would otherwise be a noncompliance with a Federal motor vehicle safety standard. Our laws and regulations do not permit this course of action. The inconsequentiality regulations (Part 556) excuse past conduct under which noncompliances have already occurred but which have ended at the time the petition is filed. A grant of an inconsequentiality petition means that the manufacturer of motor vehicles or of motor vehicle equipment is relieved of its obligation to notify purchasers of the existence of the noncompliance, and to remedy it.; Your petition for rulemaking is under evaluation, and you will b notified of the agency's decision in the near future. Until such time as the standard may be amended, all manufacturers are required to comply with all the requirements contained therein. Thus, an exemption such as you request is not possible.; As an aside, we note that the letter appears to have been signed by Herr Berg and another Bosch representative whose signature is illegible. It would be helpful to us if your letters to us would contain the name and title of the signers below their signatures, so that we can address our replies to the proper office. You may also wish to note for your records that Ms. Steed is the Administrator of NHTSA (since 1983, in fact) and that her first name is Diane, rather than Diana.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1332OpenMr. Adolph Kunasicwicz, 5644 Forest Avenue, Otter Lake, MI 48464; Mr. Adolph Kunasicwicz 5644 Forest Avenue Otter Lake MI 48464; Dear Mr. Kunasicwicz: Your request for information concerning the existence of penalties fo removal of the required certification label from a motor vehicle has been forwarded to us by the Federal Trade Commission.; The National Traffic and Motor Vehicle Safety Act requires that certification label, which under NHTSA regulations includes the name of the manufacturer and the date of manufacture, be permanently affixed to the motor vehicle. Although removal of this label does not carry a criminal penalty of either fine or imprisonment, a civil penalty of up to $1,000 is specified in certain situations.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1298OpenMr. H. Braun, Engineering Supervisor-Production, Motor Coach Industries, Inc., Pembina, ND; Mr. H. Braun Engineering Supervisor-Production Motor Coach Industries Inc. Pembina ND; Dear Mr. Braun: This is in reply to your letter of September 5, 1973, to Mr. Schneide asking whether you may furnsih (sic) side turn signal lamp for inter-city buses at the rear wheels, and if so, the required color.; It is correct that there are no Federal safety requirements for sid turn signal lamps. Therefore, there is no Federal prohibition against your providing such a lamp, and such restrictions as may exist would be those imposed by the States.; Rear mounted turn signal lamps under Federal Standard No. 108 may b either red or amber.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4560OpenMr. Jack McCroskey Ms. Glenda Swanson Lyle Regional Transportation District 1600 Blake Street Denver, CO 80202-1399; Mr. Jack McCroskey Ms. Glenda Swanson Lyle Regional Transportation District 1600 Blake Street Denver CO 80202-1399; "Dear Mr. McCroskey and Ms. Lyle: This responds to your letter o September 13, 1988, asking for our advice on potential safety hazards and legal liabilities that might result from ignoring the speed restrictions on the tires used on your transit buses. You stated that your entity operates three types of bus service in the State of Colorado. The first type is a local bus, operated primarily in areas where the speed limit is 35 miles per hour (mph), the second type is an express bus, operated primarily in areas where the speed limit is 55 mph, and the third type is a regional bus, operated primarily on freeways with speed limits of 55 to 65 mph. You were interested primarily in the tires used on your express buses. You stated that you use two types of speed-restricted tires 'almost interchangeably' on the express buses. One of your speed-restricted tire types is the XT, which is speed-restricted to a maximum speed of 55 mph. The other is the DXT, which is speed-restricted to a maximum speed of 35 mph. Since the express buses are operated primarily at speeds of 55 mph, you contacted the tire manufacturer to get its advice on the acceptability of using tires that are speed-restricted to 35 mph on these buses. You enclosed copies of correspondence you received from the manufacturer, stating that its DXT and XT tires are identical, except that the DXT tire has 7/32 of an inch more undertread. The manufacturer's advice was that the tire that is speed-restricted to a maximum of 35 mph 'may be used at higher speeds, but not for sustained operation.' You asked whether it is advisable for your entity to continue using the tires that are speed-restricted to 35 mph on your express buses, which operate primarily at 55 mph. We strongly recommend that you not do so. There are some notable advantages associated with speed-restricted tires, including enhanced load-carrying capabilities and greater resistance to tire damage from hitting objects in the road or curbs. However, the greater undertread on speed-restricted tires also means that the tires will generate higher temperatures at high speeds than a comparable non-restricted tire. Higher temperatures inside the tire increase the chances of a tire failure at high speeds. NHTSA carefully considered both the advantages of speed-restricted tires and the need to ensure that such tires are properly used when it was developing Standard No. 119, New Pneumatic Tires for Motor Vehicles Other Than Passenger Cars (49 CFR 571.119, copy enclosed). Every new bus tire must be certified by its manufacturer as complying with this standard. This agency decided that Standard No. 119 should permit the continued production of speed-restricted tires, but with appropriate safeguards to ensure that these tires would not be used at higher speeds. Accordingly, Standard No. 119 specifies less stringent high speed and endurance test requirements for speed-restricted tires. Speed-restricted tires for use on vehicles other than motorcycles are exempted from the high speed performance requirements of S6.3 of Standard No. 119. This exemption reflects the fact that the tires are not designed for high speed use. For the same reason, the endurance test schedule for speed-restricted tires consists of a lower test speed and fewer total revolutions of the test wheel, as shown in Table III of Standard No. 119. Hence, the manufacturer of these speed-restricted tires has not certified that these tires comply with the performance requirements of Standard No. 119 under conditions exceeding the speed-restriction marked on the tires. To ensure that the user of speed-restricted tires would not operate the tires at higher speeds than those at which the tires are designed to operate safely, section S6.5(e) of Standard No. 119 requires every speed-restricted tire to have the marking 'Max speed mph' on the sidewall. This marking is intended to alert the tire user of the limitations of this tire, so that it will not be repeatedly used at higher speeds. Since your express buses operate primarily at speeds of 55 mph, we urge you not to equip those buses with tires labeled 'Max speed 35 mph.' Similarly, since your express and regional buses typically operate at speeds exceeding 55 mph on their routes, we recommend only tires without speed restrictions for these buses. With respect to your question about potential legal liabilities in the event one of these speed-restricted tires fails while in service on one of your express buses, that is a question of State law. Since I am not familiar with the Colorado law on this subject, I must decline to offer an opinion. However, the Attorney General for the State of Colorado or other local counsel would be able to accurately advise you on Colorado's law in this area. Sincerely, Erika Z. Jones Chief Counsel Enclosure"; |
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ID: aiam1762OpenMr. Donald J. Gobeille,Volvo of America Corporation,Rockleigh, New Jersey 07647; Mr. Donald J. Gobeille Volvo of America Corporation Rockleigh New Jersey 07647; Dear Mr. Gobeille::#Please forgive the delay in responding to you letter of November 19, 1974, which requested an interpretation of the labeling requirements of Federal Motor Vehicle Safety Standard No. 106-74, *brake Hoses*, as applied to short lengths of vacuum brake hose.#To fit the information required by S9.1 of the standard on short lengths of hose, you have suggested a labeling format consisting of the required information presented in two lines,#>>>'each in block capital letters and numerals at least one eighth inch high, placed adjacent to one another and separated by the minimum space necessary to assure clarity. The label would occupy no more than three eighths of an inch on a hose approximately two inches in circumference (5/8 inch OD)'.<<<#Because the two lines would be close enough to prevent confusion with any optional labeling which might appear on the opposite side of the hose, it appears that the format you have described complies with the requirements of S9.1 of Standard No. 106-74. #Yours truly,Richard B. Dyson,Acting Chief Counsel; |
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ID: aiam0870OpenMr. Keith Morton, Para-Chem Southern, Inc., P.O. Box 127, Simpsonville, SC, 29681; Mr. Keith Morton Para-Chem Southern Inc. P.O. Box 127 Simpsonville SC 29681; Dear Mr. Morton: This is in reply to your letter of September 28, 1972, concerning th application of Paragraph S5.2.2 of Motor Vehicle Safety Standard No. 302, 'Flammability of Interior Materials.' You ask whether, in testing automotive interior fabrics, test specimens 'must be burned in warp and filling directions only, or does it also include testing in the face-down (inverted) positions?' As you point out, under the standard test specimens for each component are to be tested 'so as to provide the most adverse results.' This means that the relevant test result is the most adverse one achieved in any horizontal orientation, either upward- or downward-facing. How you determine which positioning of the test specimen produces the most adverse results is within your own discretion.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1277OpenMr. Donald Gary Hayes, Robertson Tank Lines Inc., P.O. Box 1505, Houston, Texas 77001; Mr. Donald Gary Hayes Robertson Tank Lines Inc. P.O. Box 1505 Houston Texas 77001; Dear Mr. Hayes: This is in reply to your letter of August 30, 1973, requesting a DO code number for retreaded tires you manufacture. It appears from your letter that the tires you retread are truck tires intended solely for your company's own use.; Any tires retreaded by and solely for use by Robertson Tank Lines ar exempt from NHTSA recordkeeping requirements and a code number is not required. As truck retreads are not subject to and Federal motor vehicle safety standard, you are also not required to place a 'DOT' symbol on them. If you retread passenger car tires, however, you are required to place a 'DOT' symbol on the tire sidewall (indicating conformity to Federal Motor Vehicle Safety Standard No. 117).; Yours truly, Richard B, Dyson, Assistant Chief Counsel |
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ID: aiam4075OpenMr. R. O. Sornson, Director, Regulatory Research and Analysis, Chrysler Corporation, P.O. Box 1919, Detroit, MI 48288; Mr. R. O. Sornson Director Regulatory Research and Analysis Chrysler Corporation P.O. Box 1919 Detroit MI 48288; Dear Mr. Sornson: This responds to your letter to Administrator Steed, asking this agenc to 'delay' its final selection of the Chrysler LeBaron GTS and Dodge Lancer car lines as 'high theft lines' for the purposes of 49 CFR Part 541, *Federal Motor Vehicle Theft Prevention Standard*. Section 603(a)(3) of the Motor Vehicle Information and Cost Savings Act (15 U.S.C. 2023(a)(3)) requires that all selections of lines initially introduced into commerce before the effective date of Part 541 (April 24, 1986) as high theft lines must be made final within one year after enactment of Title VI of the Cost Savings Act. Neither that statutory requirement nor the implementing regulations adopted by this agency contain any provision that would allow this agency to 'delay' its final selection. Accordingly, your request is denied.; In accordance with 15 U.S.C. 2023(a)(3) and 49 CFR Part 542, th National Highway Traffic Safety Administration (NHTSA) informed Chrysler of its final selection of the LeBaron and Lancer lines as high theft lines by letter dated October 25, 1985. That letter was a final agency action on this question, again in accordance with 15 U.S.C. 2023(a)(3). There is no provision in the law allowing us to 'delay' final selections, so there is no basis for entertaining your request.; You stated in your letter that the best test of whether a car lin should be treated as a high theft line is its actual theft rate. We agree with that statement. However, it does not address the issue of how to treat car lines, such as your LeBaron GTS and Lancer, for which sufficient theft data are not available.; This agency has been told repeatedly by law enforcement groups that th theft rate for a car in its initial year of introduction is almost always lower than its theft rate in subsequent model years. This is because the vehicle population is relatively small, and experiences a lesser exposure to accidents and other damage than do lines which have been available for more than one model year. Accordingly, lines are less desirable targets for chop shops in their first year of introduction than they become in subsequent model years. Because of this phenomenon, NHTSA did not believe it appropriate to make selections of high theft lines based solely or primarily on preliminary theft data.; Under section 603(a)(3) of the Cost Savings Act, the agency wa required to select not later than October 25, 1985, (one year after the date of the enactment of Title VI of the Cost Savings Act) the high theft lines from among all lines introduced between January 1, 1983, and the effective date of the theft prevention standard. To meet this statutory deadline, NHTSA published a proposal to establish a new Part 542, *Procedures for Selecting Lines to be Covered by the Theft Prevention Standard*, at 50 FR 25603, June 20, 1985. Section 542.1 set forth six proposed criteria to be used in selecting likely high theft lines from lines such as the LeBaron GTS and the Lancer, which were introduced after January 1, 1983, and before the effective date of the theft prevention standard. These criteria were:; >>>1. Retail price of the vehicle line. 2. Vehicle image or marketing strategy. 3. Vehicle lines with which the new line is intended to compete, an the theft rates of such lines.; 4. Vehicle line(s), if any, which the new line is intended to replace and the theft rate(s) of such line(s).; 5. Presence or absence of any new theft prevention devices or systems. 6. Preliminary theft rate for the line, if it can be determined on th basis of currently available data.<<<; Chrysler's comments on the proposal stated, 'We generally concur wit the proposed procedures. In our opinion the information which the NHTSA is requesting from manufacturers in order to establish anticipated theft rates for their various car lines appears reasonable.' General Motors commented that the agency should adopt some weighting of these criteria, so that the process of selecting a line as a high theft line would be more objectively defined. General Motors specifically commented, 'Probably the only criterion which could be used with any degree of certainty in selecting vehicles ... is theft data.' In the final rule establishing Part 542, NHTSA responded to this comment as follows:; >>>As noted in the NPRM, these judgments of likely high theft lines ar partially subjective judgments. NHTSA concurs with GM's statement that neither price nor vehicle image alone can be strictly correlated to vehicle theft rates. However, NHTSA believes that the six criteria set forth in Appendix C considered together do form an objective basis for predicting if a new line is likely to be a high theft line. 50 FR 34831, at 34834, August 28, 1985.<<<; NHTSA continues to believe that the six criteria form an objectiv basis for predicting if a new line is likely to be a high theft line. When these criteria were applied to the LeBaron GTS and Lancer lines, we concluded that criterion 1 did not point to the cars being either high or low theft, criteria 2 and 3 indicated the lines would be high theft, criteria 4 and 5 were not applicable, and criterion 6 indicated the cars would be low theft. On balance, then, the criteria indicated the lines will be high theft lines.; Accordingly, even if there were some authority to allow us to delay th October 25 final selections, we would still conclude that the LeBaron GTS and Lancer lines are likely high theft lines.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1627OpenMr. Edgar E. Lungren, Jr., General Attorney, Trailmobile, 200 South Michigan Avenue, Chicago, IL 60604; Mr. Edgar E. Lungren Jr. General Attorney Trailmobile 200 South Michigan Avenue Chicago IL 60604; Dear Mr. Lungren: This responds to Trailmobile's September 27, 1974 request for determination that the combination of a new trailer main body structure (underframe, floors, side walls, and nose structure) with the rear doors, lighting components, running gear, and landing gear of a used trailer, would not constitute the manufacture of a new motor vehicle subject to Federal motor vehicle safety standards. You request this determination because motor vehicles manufactured after January 1, 1975, must comply with Standard No. 121, *Air brake systems*.; Re-use of components from an existing vehicle in the construction o another vehicle may or may not result in the manufacture of a new vehicle. The NHTSA has established that the addition of new components (such as a truck body) to the chassis of a used vehicle does not constitute the manufacture of a new vehicle. Conversely, the addition of used components to a new chassis which has never been certified in a vehicle constitutes the manufacture of a new vehicle subject to the safety standards in effect for that vehicle class on the date of manufacture. This criterion has been relied on in the area of chassis-cab multistage manufacture.; Since Trailmobile plans to utilize a new underframe as well as a ne upper structure in the construction of these trailers, we consider that the operation you describe constitutes the manufacture of a new motor vehicle for purposes of application of the safety standards, and Standard No. 121 applies to those trailers manufactured by this process on or after January 1, 1975. To conclude otherwise would mean that re- use of running gear assemblies and rear doors could indefinitely exempt a vehicle from upgraded and newly-issued safety standards.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam2908OpenMr. Dick Palmer, Palmer Machine Works, Old Round House Road, Amory, Mississippi, 38821; Mr. Dick Palmer Palmer Machine Works Old Round House Road Amory Mississippi 38821; Dear Mr. Palmer: This is in response to your letter of November 10, 1978, concernin Federal Motor Vehicle Standard No. 115, *Vehicle identification number*, and in confirmation of your telephone conversation with Mr. Schwartz of my office.; Unfortunately, we do not have a simplified version of the standar which applies only to trailers. We have also modified the standard somewhat since the August 1978 version you referred to in your letter. I have attached a copy of the modification as well as a proposed further modification. I realize this is a complex standard, and, therefore, offer the following comments:; 1. Since you produce less than 500 vehicles per year, characters 1, 2 3, 11, 12 and 13 of the VIN will represent your manufacturer identifier. The date by which your manufacturer identifier must be submitted to the NHTSA has been changed to September 1, 1979. It is our understanding that the Society of Automotive Engineers will be willing to help you determine your manufacturer identifier. You should contact: Mr. Leo Ziegler, Society of Automotive Engineers, 400 Commonwealth Drive, Warrendale, Pennsylvania 15096, (412) 776-4841.; 2. The 4th, 5th, 6th, 7th and 8th characters of the VIN represen descriptive information about your vehicles. In the case of trailers, the type of trailer, series, body type, length and axle configuration must be represented. Since your model number can be associated with all these characteristics, you may want to incorporate it into the vehicle descriptor section.; 3. The 9th character of the VIN represents the model year of th vehicle, and should be determined from Table II which appears in the standard.; 4. The 10th character of the VIN represents the plant of manufacture Since your firm has only one plant, you may choose any character you desire except one specifically precluded by the standard.; 5. Since your firm manufacturers less than 500 vehicles each year, th last three characters of the VIN represent the number that is sequentially assigned to a vehicle in your production process.; 6. The check digit which immediately precedes the third character o the VIN is determined by the mathematical operation described in section S5 of the standard. Since most characters in your VIN will be standardized, the check digit should be fairly easy to determine.; Please contact me if you have any further questions. Any trad associations to which you belong should also be helpful in establishing your VIN procedures.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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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.