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: aiam1694OpenMr. John A McLaine, Chief, Automotive Engineering Standards, State of New Jersey, Division of Motor Vehicles, 25 South Montgomery Street, Trenton, NJ, 08666; Mr. John A McLaine Chief Automotive Engineering Standards State of New Jersey Division of Motor Vehicles 25 South Montgomery Street Trenton NJ 08666; Dear Mr. McLaine: This is in reply to your letter of November 13, 1974 expressing you opinion that the Front Brake Light Adapter causes 'front signal lamps [to] become stop lamps which do not meet Standard 108.' You ask for our concurrence in this interpretation.; In our view, the Adapter does not convert front signal lamps into sto lamps, even though their purpose is to indicate a vehicle stop. Since the vehicle on which the system is installed will be equipped with conventional red rear-mounted stop lamps, the Adapter is considered only as additional lighting equipment that may be installed unless it impairs the effectiveness of the required equipment. You have informed us that it does not override the flashing effect of the front signal lamps, and therefore, Standard No. 108 does not forbid its use as original equipment, or as replacement equipment for a similar system that has been original equipment on a motor vehicle. Its sale in the aftermarket and use as an accessory device, however, would be subject to New Jersey law.; You have also made the general comment that 'New Jersey laws requir all lamps or motor vehicles registered in New Jersey to meet the SAE Standards.' I am sure you are aware that under Section 103(d) of the National Traffic and Motor Vehicle Safety Act, Standard No. 108 preempts State laws on all aspects of performance that the standard covers. This means that if Standard No. 108 allows a deviation from a referenced SAE standard, or if the referenced SAE standard differs from the current SAE standard, the SAE-referenced requirements of Standard No. 108 preempt New Jersey's requirements, unless they are identical.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam1650OpenMr. John R. Lutz, Assistant General Counsel, Skyline Corporation, 2520 By-Pass Road, Elkhart, IN 46514; Mr. John R. Lutz Assistant General Counsel Skyline Corporation 2520 By-Pass Road Elkhart IN 46514; Dear Mr. Lutz: This is to confirm conversations you had on October 16 and 24, 1974 with Mr. Michael Peskoe of NHTSA's Chief Counsel's Office, regarding defect notification campaign 74-0149, which involves safety related defects in certain Skyline travel trailers. We wish to confirm our understanding that Skyline has agreed to send notification letters identical to that forwarded to us by your letter of October 4, 1974, to all owners of Skyline travel trailers involved in this campaign who have not at the time of mailing had their vehicles inspected, regardless of whether such purchasers were mailed a copy of an earlier notification letter.; We will consider the notification letter forwarded to us on October 4 1974, to conform to the requirements of the National Traffic and Motor Vehicle Safety Act for purposes of this particular campaign. The October 4 letter is based on our letter to you of September 23, 1974, in which we reviewed an earlier notification letter forwarded to us on September 12, 1974. However, it now appears that while we indicated certain areas in which this earlier letter failed to conform to 49 CFR Part 577, we inadvertently overlooked certain other instances in which the letter did not conform. Consequently, both the earlier letter and the letter of October 4 fail to contain information in response to the requirements of S 577.4(e)(1)(ii) and (iii). These requirements specify that the manufacturer must include an estimate of both the day by which repair parts will be available at repair facilities and the time necessary to perform the work involved in correcting the defect. The former calls for the manufacturer to specify a given day, while the latter calls for an estimate in terms of hours. While we do not request further revision of the letters sent in this campaign, these information items should be included in notifications sent in any future campaigns.; We appreciate your cooperation in the recall and repair of the Skylin trailers involved in this campaign, and trust we can rely on your continued cooperation in the future.; Sincerely, Andrew G. Detrick, Acting Director, Office of Defect Investigation, Motor Vehicle Programs; |
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ID: aiam4310OpenMr. Leon Steenbock, Administrative Manager, Engineering, FWD Corporation, Clintonville, WI 54929-1590; Mr. Leon Steenbock Administrative Manager Engineering FWD Corporation Clintonville WI 54929-1590; Dear Mr. Steenbock: This responds to your April 10, 1987, letter to my office asking abou the applicability of Federal Motor Vehicle Safety Standard No. 206, *Door Locks and Door Retention Components,* to door locks on fire trucks. You enclosed a copy of an August 13, 1980, letter to you from former Chief Counsel Frank Berndt and asked whether Mr. Berndt's opinion concerning fire truck door locks is current. The answer is yes.; In 1985, the National Highway Traffic Safety Administration amende Standard No. 206 to exempt doors equipped with wheelchair lifts from the requirements of the standard. However, since that amendment has no bearing on door locks for fire trucks and because we have made no changes to the standard that would effect fire trucks, we confirm that the agency's 1980 interpretation has not been superseded or revised by subsequent interpretations of or amendments to the standard.; For your information, I have enclosed a current copy of Standard No 206 and information on how you can obtain copies of our motor vehicle safety standard and other regulations.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam0720OpenMs. Donna M. Barnard, Owner, Scott's Trailer Market, 2020 E. Fremont Street, Las Vegas, NV 89101; Ms. Donna M. Barnard Owner Scott's Trailer Market 2020 E. Fremont Street Las Vegas NV 89101; Dear Ms. Barnard: This is in reply to your letter of May 10, 1972 to Mr. E.T. Drive requesting further clarification of the Tire Identification and Record Keeping regulations concerning your responsibility as a seller of trailer coaches.; The regulation does not distinguish between the responsibility o manufacturers, distributors and dealers of trailer coaches as opposed to manufacturers, distributors and dealers of other type vehicles. Therefore, a manufacturer of a trailer coach is required, pursuant to section 574.10 of the regulation, to maintain a record of tires shipped on or in the vehicle and the name and address of the purchaser of the vehicle. The manufacturer is free to use the tire identification system on the tire or any other system as long as the system would enable him to notify the purchaser of the vehicle in the event the tires the vehicle is equipped with become the subject of a recall. Therefore, in most cases, if the manufacturer obtains the name of the purchaser from the seller and is able to identify the tires on the vehicle, he is able to meet this requirement. The method the manufacturer uses to maintain a record of the tires on the vehicle appears to vary, but the efficiency of that record is the responsibility of the manufacturer.; On the other hand, if the vehicle dealer changes tires prior to th sale to the user, the manufacturer is no longer responsible for maintaining the record of the tires on the vehicle. In this case section 574.9(b) of the regulation would apply and the vehicle dealer would have to send the name and address of the purchaser of the vehicle, the tire identification number of the tire on the vehicle, and the dealer's name and address to the manufacturer of the tires.; For your convenience enclosed is a copy of the regulation. Sincerely, David Schmeltzer, Assistant Chief Counsel |
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ID: aiam4295OpenMr. James E. Campbell, 2719 So. 29th Street, Ft. Pierce, FL 33450; Mr. James E. Campbell 2719 So. 29th Street Ft. Pierce FL 33450; Dear Mr. Campbell: This is in reply to your letter of December 17, 1986, in which you hav asked the following question:; 'If someone has a patent on an invention, as in the case of the tur signals, and you at the N.H.T.S.A. make it mandatory that all cars be equipped with that feature, does the inventor retain the marketing rights to that invention, or does he lose those rights once it becomes mandatory?'; The answer to your question is that rights given under a patent issue by the United States Patent Office cannot be divested by the actions of a governmental agency such as the N.H.T.S.A. Were we to require that a patented item of equipment be standard on all passenger cars, the patent holder would retain all rights. However, it is important that you understand that the agency does not mandate the adoption of equipment of a proprietary nature. By law, the Federal motor vehicle safety standards are defined as minimum standards for motor vehicle *performance*, to the extent practicable the standards specify performance requirements to be met (*e.g.*, no more than 5 ounces of fuel spillage in the first 5 minutes following a 30 mph frontal barrier collision), leaving the design solution to the manufacturer who may incorporate proprietary components if he chooses.; The performance requirements of our standards vary in their degree o specificity. In some instances the agency has had to develop fairly specific requirements to ensure uniformity and interchangeability of replacement equipment items such as brake hoses, tires, and lighting equipment. This can increase the likelihood of the incorporation of proprietary elements. Many of the changes which are made to the standard are made in response to petitions from manufacturers of motor vehicles or motor vehicle equipment. This is especially true in the area of motor vehicle lighting which is covered by Standard No. 108. In some instances, a petitioner may request a change which incorporates specifications which are covered by a patent. In these cases, the agency endeavors to insure that the technology is made available on a non-exclusive royalty-free basis to all who wish to use it before amending the standard.; I hope that this answers you question. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1890OpenMr M. J. Denholm, Power Controls Division, Midland-Ross Corporation, 490 South Chestnut Street, Owosso, MI 48867; Mr M. J. Denholm Power Controls Division Midland-Ross Corporation 490 South Chestnut Street Owosso MI 48867; Dear Mr. Denholm: This responds to Midland-Ross' March 19, 1975, questions whether S5.7. of Standard No. 121, *Air brake systems*, (as effective September 1, 1976) specifies reservoirs that are charged to 100 psi before or after introduction of a failure as specified in S5.7.1, static or dynamic testing of emergency brake system application and release, and design limits of 1 to 60 psi for emergency brake system application and release. You also asked whether S5.7.4(c) requires modulation of the towed vehicle emergency system in cases of control line failure, and whether such a failure qualifies as a 'single failure in the service brake system' for purposes of emergency brake system performance under S5.7.1.; Section S5.7.3 specifies emergency application and release capabilit with all air reservoirs charged to 100 psi, followed by introduction of a failure. The vehicle is tested for this application and release capability statically. In our reconsideration of this amendment, NHTSA will consider a clarification of this language.; The maximum of 1 psi for pressure release and minimum 60 psi fo pressure application are intended only as objective measures of what constitute an application or a release. In the petitions for reconsideration of this amendment, it has been suggested that the ability to move the vehicle and then stop it after an emergency brake application would permit greater design freedom in the design of emergency brake systems. This issue will be addressed in our response to petitions for reconsideration.; Section S5.7.4(c) requires that a towing vehicle be capable o modulating the air in the supply or control line following a single failure in the service brake system on the towing vehicle, but does not require modulation of the towed vehicle emergency brake system under any circumstance (including control line failure).; This language is intended to assure that a single failure in the truc itself will not prevent modulation of an unimpaired system from the tractor protection system rearwards. A clarification of this language may be necessary.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3283OpenMr. D. J. Hitt, Vice President, Safety and Security Consultants, 702 Candy Mountain road, Birmingham, AL 35217; Mr. D. J. Hitt Vice President Safety and Security Consultants 702 Candy Mountain road Birmingham AL 35217; Dear Mr. Hitt: This is in reply to your letters of April 11, and April 25, 1980 respectively to this agency and to Mr. Vinson of this office, (sic) These letters reference requirements for side marker reflectors and clearance lamps for trailers used to carry agricultural products over the public roads.; You say that your trailers travel 'as much as several hundred miles o the highways at all hours of the day and night'. Therefore, they are 'motor vehicles' subject to all applicable Federal Motor Vehicle Safety Standards.; I enclose a copy of Federal Motor Vehicle Safety Standard No. 10 (Title 49, Code of Federal Regulations, section 571.108). You will see that marker lamps and reflectors are required on all trailers, while rear clearance lamps need be added only if the overall width of a trailer is 80 inches or more. A clearance lamp facing to the rear may be combined with a rear side marker lamp, we assume that is what you mean by a 'side clearance lamp' as the standard speaks only in terms of 'front' and 'rear' clearance lamps.; You have also asked for the 'early history' of why these lamps ar required pursuant to 'Regulation No. 393.15.' As a matter of clarification that section of Title 49 is enforced by a different agency, the Bureau of Motor Carrier Safety Federal Highway Administration, and covers lighting equipment required for commercial vehicles being used in interstate commerce. Our lighting standard, essentially identical, must be met before the vehicle is used, i.e., from time of manufacture until time of sale. To answer your question, clearance lamps must indicate the overall width of the trailer, in order that other drivers may be alerted to the presence on the road of a large vehicle. Side markers help identify the presence of a vehicle whose head lamps or taillamps may not be seen by a driver approaching it from a 90 degree angle, such as at an intersection.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0759OpenMr. T. C. McLaughlin, McLaughlin Equipment Co., Box 2765, 320 27th Street, Fargo, ND 58102; Mr. T. C. McLaughlin McLaughlin Equipment Co. Box 2765 320 27th Street Fargo ND 58102; Dear Mr. McLaughlin: This is in reply to your letter of May 17, 1972, concerning th remounting of old school bus bodies on new chassis. You indicate that this practice is occurring in North Dakota, enclose an advertising brochure of a company that performs the service, and also enclose a copy of a letter from Mr. Robert B. Klure of the Divco-Wayne Corporation which discusses possible safety problems that may result from this practice. You have asked us to outline actions and procedures that can be taken by the NHTSA or your office to curtail this practice.; The NHTSA considers the mounting of an old school bus body on a ne chassis to be manufacturing of a vehicle, which must conform to all applicable motor vehicle safety standards in effect on the day of the manufacture of the chassis, or of the completed vehicle. The failure of a school bus manufactured in this fashion to conform to applicable standards would be a violation of section 108(a)(1) of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1397(a)(1)), and could subject its manufacturer to civil penalties and other sanctions. In addition, such vehicles must be certified as conforming to all applicable standards, and the failure of a manufacturer to certify can also result in the imposition of similar sanctions.; It appears from the discussion of safety problems in Mr. Klure's lette that the mounting of old school bus bodies on new chassis creates safety problems that the NHTSA might consider to be safety related defects. If a finding is made by NHTSA that such a defect exists, the manufacturer would be required to notify owners of the defect, and the NHTSA would probably urge the manufacturer to conduct a recall campaign.; In either case the NHTSA will take steps to see that all manufacturer are complying with NHTSA requirements. You can assist us by providing the names of companies which you believe are engaging in this practice. This information should be sent to Mr. Francis Armstrong, Director, Office of Standards Enforcement, National Highway Traffic Safety Administration, 400 7th Street, S.W., Washington, DC 20590.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1945OpenMr. Steve Abel, Controller, Franklin Coach Company, Inc., P. O. Box 152, Nappanee, IN 46550; Mr. Steve Abel Controller Franklin Coach Company Inc. P. O. Box 152 Nappanee IN 46550; Re: Draft defect notification letter, CIR-910 Dear Mr. Abel: Thank you for submitting your draft defect notification letter for ou review. We find that the draft fails in several respects to conform to regulations specifying the content of the notification (49 CFR Part 577, *Defect Notification*, copy enclosed). First the reference in the second sentence of your letter to 'your motor home' does not contain the identifying criteria required by section 577.4(b)(1). The sentence should more objectively identify the motor home, preferably by model number and name.; It appears from the facts you present that in addition to adding ne leaf springs, the certification label on the vehicles should be replaced. An upgrading of the vehicle's carrying capacity should be reflected in both its gross vehicle and axle weight ratings. A correct certification label should reflect the values as they apply to the repaired vehicle. Your notification letter should therefore specify steps the owner can take to correct the certification label (S577.4(e)). One method you should consider is to furnish to each owner a corrected certification label with instructions for its installation by him.; Your letter also fails to conform to section 577.4(e)(3), which applie when the manufacturer does not offer to assume the cost of the repair. It appears from your description that you are modifying the existing springs, and they should be identified by name and part number (S577.4(e)(3)(ii)). You also have not provided a required detailed description (including appropriate illustrations) of each step required to repair the defect (S577.4(e)(3)(iv) (sic).; Finally, the requirements of section 577.4(e)(3)(iii) require th manufacturer to take positive steps to determine the availability of repair parts. You are obligated to at least determine whether the parts you recommend for replacement are in fact available. We do not believe you have met this requirement by merely stating that the parts 'should be available.' You can probably obtain this information by contacting the vehicle manufacturer, or by finding comparable repair parts in the replacement market.; Yours truly, James C. Schultz, Chief Counsel |
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ID: aiam3118OpenMr. Walter Arrowsmith, Administrative Assistant, Bureau of Motor Vehicles, P.O. Box 16520, Columbus, OH 43216; Mr. Walter Arrowsmith Administrative Assistant Bureau of Motor Vehicles P.O. Box 16520 Columbus OH 43216; Dear Mr. Arrowsmith: This is to memorialize the telephone conversation you had with Kath DeMeter of my staff on Thursday, October 4, 1979, concerning the motor vehicle manufacturers' certificate of origin. You indicated to Ms. DeMeter that the new standard certificate of orgin (sic) has an assignment form on the reverse side for the transfer from the first dealer to the consumer. This assignment contains odometer information, including identifiers of the vehicle, a reference to Federal law, a statement of the odometer reading, a statement that the reading is actual unless one of two other statements (mileage not actual or mileage over 99,999 miles) is checked, the names and addresses of the buyer and the seller, and the signature of the seller. Ms. DeMeter informed you that in order for the certificate to substitute for a separate Federal odometer disclosure statement, it must include the signature of the buyer. Ms. DeMeter also indicated that when the assignment form is being used to transfer the vehicle from the dealer to another, the odometer information is not required under Federal law.; Sincerely, John Womack, Assistant Chief Counsel for General Law an Legislation; |
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.