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: aiam4471OpenCaptain Robert W. Barthelmess Box 5744 APO, NY 09633; Captain Robert W. Barthelmess Box 5744 APO NY 09633; "Dear Captain Barthelmess: This is in reply to your letter of Decembe 30, 1987, to this agency with respect to the requirements for importing tires without the DOT symbol. You have asked whether the DOT symbol must still appear on the tires of vehicles that conform to the U.S. Federal motor vehicle safety standards. The answer is yes, there has been no change in the requirement that the DOT symbol appear on the sidewall of tires manufactured as either original or replacement equipment. The DOT is the manufacturer's certification of compliance with all applicable Federal motor vehicle safety standards. In your letter, you stated that one individual at the Army Air Force Exchange Service indicated that the DOT symbol had been replaced by a series of numbers. This individual may have confused the requirement for the DOT symbol with a different Federal requirement for an identification number to appear on tires. The tire identification number, among other things, assists in the tracing and recalling of tires which may prove to be noncomplying or defective. The requirement for the tire identification number is in addition to, not in place of, the requirement for the DOT symbol. You have also asked (with reference to service personnel like yourself who recently bought non-DOT marked tires for your U.S. type automobiles) whether there is a technical possibility of denial of entry to vehicles certified as meeting U.S. safety specification but equipped with tires not bearing the DOT symbol. The general procedure is that when a motor vehicle arrives at the port of entry it will be inspected to see whether it bears the manufacturer's certification of compliance (generally in the driver's door post area). We do not know whether Customs makes it a practice to inspect vehicles of U.S. origin for this certificate when a serviceman is returning to the States. If an inspection occurs and the vehicle bears the certification, the vehicle is admitted without further inspection. It is possible, of course, that a Customs inspector could happen to notice in passing the lack of the DOT symbol on the tires. In this instance, as the vehicle would not be in conformity with all applicable standards, the Customs inspector could require entry of the vehicle under bond, which would be released upon the importer's production of a statement to this agency that the noncompliance had been corrected. Although we are not aware of any instance in which this has actually happened, you may wish to contact Customs with respect to its inspection procedures. You may also wish to write Goodyear asking for a statement that the Vector tires comply with Standard No. 109, which could be presented to Customs should questions arise. I hope that this answers your questions. Sincerely, Erika Z. Jones Chief Counsel"; |
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ID: aiam1389OpenMr. Evan Hammond, Manager - Central Engineering, Trailmobile Technical Center, 5570 Creek Road, Cincinnati, OH, 45292; Mr. Evan Hammond Manager - Central Engineering Trailmobile Technical Center 5570 Creek Road Cincinnati OH 45292; Dear Mr. Hammond: In your letter of January 21, 1974, you cite the provision of Standar No. 108 under which 'the height of the rear clearance lamps is optional if the identification lamps are located at the top of the trailer', and suggest that a similar option be adopted for identification lamps, *i.e.*, that their height location 'be made optional if the rear clearance lamps are located as close to the top of the closed van trailer as practical'.; Clearance lamps are required by Standard No. 108 to 'indicate th overall width of the vehicle . . . as near the top as practicable'. The primary purpose of these lamps is to indicate the overall width of the vehicle, and the secondary purpose is to indicate the overall height. Identification lamps on the other hand are a system (three lamps with specified spacing) located 'as near the top as practicable'. The sole purpose of this system is to identify a vehicle as one of large size. When the widest part of a vehicle is at a point other than the highest point, such as when the fenders are separate or protrude from the body, the option in Standard No. 108 in effect allows the clearance lamps to be mounted at the widest point even though it would be practicable to mount them higher, as long as the identification lamps are mounted at the top of the vehicle, thus fulfilling the secondary function of the clearance lamps. Since the identification lamps are a system serving only the one function of identification, the clearance lamps cannot act as substitutes and the system must be mounted at the point of maximum visibility ('as close as practicable to the top of the vehicle'). To adopt your suggestion would allow a manufacturer to mount the system at the bottom of a vehicle even if it is practicable to mount them at the top, thus substantially negating the identification function the system serves. For this reason we cannot adopt the option your suggest.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0961OpenMr. David C. Williams, Vice President, Eastman Chemical Products, Inc., Kingsport, TN 37662; Mr. David C. Williams Vice President Eastman Chemical Products Inc. Kingsport TN 37662; Dear Mr. Williams: This is in reply to your letter of December 15, 1972, requesting a opinion as to whether certain identification marks and certification statements Eastman Chemical plans to use in marketing Uvex plastic sheet will conform to Standard No. 205, 'Glazing Materials', as amended November 11, 1972, 1972 (37 F.R. 24035), and to section 114 of the National Traffic and Motor Vehicle Safety Act, which requires the certification of motor vehicles and equipment as conforming to applicable standards. You submit two sample markings: one for use by Eastman when it sells that material to further manufacturers, whom you refer to as 'fabricators', and one for use by persons other than Eastman. Similarly, you submit two certification statements, one for use by Eastman, and the other for use by its customers.; Based upon our previous dealings with Eastman regarding this product it does not seem to us that a person other than Eastman Chemical can be considered the 'fabricator' of Uvex sheet. The term 'fabricate', which is used along with 'laminate and temper' to distinguish prime glazing material manufacturers from other manufacturers, is used in the standard in its ordinary dictionary meaning, which we consider to be 'manufactures' or 'creates'. Accordingly, we have assumed Eastman to be the prime manufacturer of the material in answering the questions you raise.; The markings which you indicate will be used by Eastman will conform t the requirements of paragraph S6.1 of Standard No. 205 (assuming the letters and numbers conform to the size requirements of Section 6 of ANS Z26). If the material is to be used as a component of a specific motor vehicle or camper Eastman would be required, after April 1, 1973, to conform to paragraph S6.2 as well, by including in the mark Eastman's assigned DOT code number.; The label stamp you will supply to your customers will conform to th requirements of S6.4.; With respect to the statements you plan to use for certificatio purposes, we believe them to be unnecessarily ambiguous, and therefore to be of doubtful legal effect in meeting the certification requirement. It is the responsibility of Eastman to certify the conformity of the product to the standard. The basis for that certification is the manufacturer's entire process from design to final production. Tests which show that the material conforms are only one factor in the situation, and reference to them in the certification statement is inappropriate. We feel similarly with respect to your statement that you certify the material as meeting 'high manufacturing standards.' We recommend you certify with the statement, 'This material conforms to all applicable Federal motor vehicle safety standards.' In cases where the material will be altered by other manufacturers, they can, where possible, allow this label to remain in place, or affix a new label with the same statement.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1673OpenMr. John W. Wooster, Wooster's Automotive, 1185 Palm Avenue, Imperial Beach, CA 92032; Mr. John W. Wooster Wooster's Automotive 1185 Palm Avenue Imperial Beach CA 92032; Dear Mr. Wooster: This is in reply to your letter of August 22, 1974, in which yo describe a particular 5-yard dump truck which you purchased and ask whether the vehicle's weight ratings are consistent with federal requirements. You describe the vehicle as having a gross vehicle weight rating of 15,000 pounds. However, when loaded with 4-5 yards of topsoil, which you state is not an abnormal load for the truck, the vehicle weight exceeds the stated gross vehicle weight rating. The weight of the unloaded vehicle is 8600 pounds.; NHTSA Certification regulations require the vehicle manufacturer t specify on the vehicle's certification label a gross vehicle weight rating, and a gross axle weight rating for each axle. The gross vehicle weight rating must be at least the sum of the unloaded vehicle weight, 150 pounds for each passenger, and the vehicle's rated cargo load (49 CFR S567.5(a)(5)). While the unloaded vehicle weight and passenger weight can be determined objectively, the rated cargo load is a figure set by the manufacturer, based on his own assessment of the vehicle's carrying capacity and the maximum load at which the vehicle may be safely operated. The NHTSA accepts such ratings by manufacturers when established in good faith. the ratings on the certification label are intended to advise purchasers of the load limitations for the vehicle and should be considered at the time of purchase. We cannot say, therefore, on the basis of the facts you present, that the vehicle failed to conform to Federal requirements. Moreover, we cannot agree with your statement that the 'size of the brakes' do not comply with federal standards. No Federal braking standards were applicable to truck manufactured at the time this truck was purchased (July 1973).; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam4021OpenMr. William E. Sandham, Sales Manager, OEM Division, Velvac, Inc., 2900 South 160th Street, New Berlin, WI 53151; Mr. William E. Sandham Sales Manager OEM Division Velvac Inc. 2900 South 160th Street New Berlin WI 53151; Dear Mr. Sandham: Thank you for your letter of May 21, 1985, concerning the vertica adjustment of rearview mirrors for trucks. You asked us to clarify whether the standard requires a mirror both to tilt, as shown in your sketch 'A,' and to move up and down its mounting bracket, as shown in your sketch 'B.' As discussed below, a truck mirror can meet the adjustment requirement by either tilting or by moving up and down its mounting bracket.; The agency has not specified the means used to provide a vertica adjustment. We would consider a mirror which tilts, as shown in your sketch 'B,' as meeting the adjustment requirement. You should know that the agency has interpreted this vertical adjustment requirement for trucks to mean that adjustment with tools is allowed. The use of tools is justified because trucks and buses are generally driven for longer periods of time by the same driver and thus the mirror does not have to be continually adjusted.; Please note that S6.1(a) of Standard No. 111 also permits trucks with GVWR of 10,000 pounds or less to be equipped with rearview mirrors which meet the performance requirements for passenger cars in section S5, instead of the requirements for trucks in S6.1(b), S7, or S8. If the passenger car specifications are chosen, the driver must be able to adjust the inside and outside rearview mirrors in both vertical and horizontal directions by tilting them. The agency has not permitted the use of tools for adjusting passenger car mirrors, since passenger cars are often driven by different drivers who will need to quickly and easily adjust their mirrors. A mirror mounted on a universal ball socket joint, for example, meets this requirement. In this situation, the vertical tilting adjustment shown in your sketch 'A' would appear to comply as long as that mirror could also be adjusted horizontally by tilting. The vertical sliding adjustment shown in sketch 'B' apparently would not meet this requirement because it appears to require the use of tools to make the adjustment.; A copy of the current version of Standard No. 111 is enclosed. I hop this information is helpful to you.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1223OpenMr. Jerry M. Schneider, 5475 Northwest highway, Chicago, Illinois 60630; Mr. Jerry M. Schneider 5475 Northwest highway Chicago Illinois 60630; Dear Mr. Schneider: This is in response to your letter of August 21, 1973, asking whethe Standard 125 Warning devices are required to be installed as original equipment in motor homes by the manufacturer.; Standard 125 is an equipment standard, not a vehicle standard. Thi means that it is directed at the manufacturer of the devices, not vehicle manufacturers. Therefore the standard doesnot(sic) make installation of the device mandatory in any motor vehicle. The Bureau of Motor Carrier Safety, however, has made the use of the device mandatory by interstate carries subject to its regulation.; For your information, future requests for information should b directed to the Administrator, National Highway Traffic Safety Administration, 400 Seventh Street, S.W., Washington, D.C. 20590, and not the Docket Section, which essentially is a repository of comments which do not receive a reply.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam5260OpenMr. Ray Paradis Manufacturing Manager Dakota Mfg. Co., Inc. Box 1188 Mitchell, SD 57301; Mr. Ray Paradis Manufacturing Manager Dakota Mfg. Co. Inc. Box 1188 Mitchell SD 57301; Dear Mr. Paradis: This responds to your FAX of November 18, 1993 requesting a clarification of our letter of November 16 as it applies to the rear of the trailers shown in items; 5 and 7 which accompanied your letter of August 31, 1993. As we advised yo with respect to rear markings, Standard No. 108 requires a horizontal strip of retroreflective sheeting across the full width of the trailer. With respect to the trailer shown in; 7, retroreflective tape can be applied across the full width of th 'approach ramp' to meet the requirements since the ramp will be in the down position when the trailer is moving. As we further advised you, paragraph S5.7.1.3(b) anticipates that the length of the color segments may have to be modified to facilitate using material near rear lamps. In the worst cases of trailers with rear surfaces no wider than the minimum required for lamps, breaks in the rear treatment are unavoidable to clear the lamps. But NHTSA expects the manufacturer to minimize the breaks by using red material adjacent to red lamps. With respect to; 5, we recommend applying red/white conspicuity treatment on either sid of the identification lamps, with red material used in the remaining outboard areas. I hope that this answers your questions. Sincerely John Womack Acting Chief Counsel; |
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ID: aiam0598OpenMr. John Hall, Dayton Steel Foundry Company, P.O. Box 1022, Dayton, OH 45401; Mr. John Hall Dayton Steel Foundry Company P.O. Box 1022 Dayton OH 45401; Dear Mr. Hall: This is in reply to your letter of February 2, 1972, in which you aske whether the temperature range specified in S6.2.6 of Motor Vehicle Safety Standard No. 121 was an initial temperature range or a range applicable throughout the stop.; In the new issuance of the standard, published in the February 24 1972, issue of the *Federal Register*, the section has been amended to make it clear that the range is the range of initial brake temperature on each stop.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4888OpenMr. David McCormick First Company 9571 Alden Lenexa, KS 66215; Mr. David McCormick First Company 9571 Alden Lenexa KS 66215; Dear Mr. McCormick: This responds to your letter to Stephen Wood, ou Assistant Chief Counsel for Rulemaking, seeking information about any provisions of Federal law that might apply to a belt positioning device for children. Based on the information provided in your letter, it appears that this device attaches to the seat back of the rear seat and includes an adjustable cushioned head support and an adjustable 'convenience center,' which serves to reroute the belt to offer a better belt fit for a child occupant of the position. For your information, I have enclosed two letters in which we have provided a general description of how Federal requirements might apply to belt positioning devices. The first is a February 11, 1988 letter to Mr. Roderick Boutin and the other is a November 22, 1988 letter to Ms. Claire Haven. These letters explain the applicable Federal requirements and the letter to Mr. Boutin sets forth some safety concerns applicable to that particular design. In addition, I have enclosed an information sheet for new manufacturers of motor vehicles and motor vehicle equipment that explains how to obtain copies of our safety standards and other regulations. I hope this information is helpful. Sincerely, Paul Jackson Rice Chief Counsel; |
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ID: aiam0062OpenMr. Jack Cedarblade, Northern California Ready Mixed Concrete and Materials Association, 155 Montgomery Street, San Francisco, CA 94104; Mr. Jack Cedarblade Northern California Ready Mixed Concrete and Materials Association 155 Montgomery Street San Francisco CA 94104; Dear Mr. Cedarblade: Thank you for your letter of April 8, 1968, to Mr. George Nield concerning the location requirements for clearance lamps as specified by Federal Motor Vehicle Safety Standard No. 108.; Enclosed is a copy of the Federal Motor Vehicle Safety Standards (wit amendments and interpretations through February 15, 1968). Standard No. 108 appears on page 39 of this publication. The location requirements for clearance lamps are included in Table II (page 50), of the standard. Since the requirements specify locations as near as practicable to the upper left and right extreme edges of the vehicle, the exact locations will vary, depending upon the design and utilization of the vehicle on which the lamps are mounted. When the rear identification lamps are mounted at the extreme height of the vehicle, rear clearance lamps may be mounted at optional heights. I would also point out that Standard No. 108 is applicable to new vehicles manufactured for sale on or after the effective date of the standard.; With respect to the requirements of Standard No. 108, I must point ou that this Bureau does not issue approvals on items of lighting equipment or on vehicle designs incorporating this equipment. Therefore, the above comments are for your information only and in no way relieve the vehicle manufacturer from his responsibility for certifying that the assembled vehicle meets the requirements of the standard.; Thank you for writing. Sincerely, David A. Fay, Office of Standards on Accident Avoidance Motor Vehicle Safety Performance Service; |
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.