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: aiam0183OpenMr. Arna Gunntorp, Development Department, Gummifabriken Gislaved Aktiebolag, 33200 Gislaved, Sweden; Mr. Arna Gunntorp Development Department Gummifabriken Gislaved Aktiebolag 33200 Gislaved Sweden; Dear mr. Gunntorp: #In response to your letter of November 3, 1969, th Department of Transportation hereby assigns number *210* to the Gummifabriken Gislaved Aktiebolag, Gislaved, Sweden, as its approved code mark. The approved code mark is for use in identifying the tire manufacturer in accordance with S4.3 of Federal Motor Vehicle Safety Standard No. 109 and the National Traffic and Motor Vehicle Safety Act of 1966 (15 USC 1421 (1)). #Your attention is directed to the requirement for designation of an agent in accordance with the National Traffic and Motor Vehicle Safety Act of 1966, Subsection (110(e)). This requirement is implemented by our 'General Procedural Rules, Subpart D - Service of Process, Agents.' #As required, I have enclosed a copy of the Federal Motor Vehicle Safety Standards No. 109 and No. 110 with amendments. #Sincerely, Roger H. Compton, Director, Office of Standards on Accident Avoidance, Motor Vehicle Safety Performance Service; |
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ID: aiam0428OpenMr. William H. Lawson, Jr., Manager, Market Development, Sierracin Corporation, 12780 San Fernando Road, Sylmar, CA 91342; Mr. William H. Lawson Jr. Manager Market Development Sierracin Corporation 12780 San Fernando Road Sylmar CA 91342; Dear Mr. Lawson: This is in reply to your letter of August 4, 1971, in which yo enclosed a copy of the manufacturer's symbol that would be used to identify windshields manufactured by the Sierracin Corporation, and ask whether the symbol is acceptable as illustrated. You also request our comments on requirements for the label location on the product.; The symbol you have enclosed complies with Motor Vehicle Safet Standard No. 205, 'Glazing Materials' and, except for the omission of a hyphen between the 'DOT' symbol and the manufacturer's code mark, also with the marking requirements proposed in the notice of January 9, 1971 (36 F.R. 326), which would amend certain provisions of the standard. We would consider this deviation to be inconsequential.; With reference to location requirements, the present standard does no specify a location for the windshield marking. The proposed amendment, which is still under consideration, would require the mark to be placed in the lower left hand corner of the windshield.; Sincerely, Lawrence R. Schneider, Acting Chief Counsel |
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ID: aiam1597OpenMr. Bernard E. Wuthrich, Pan Commercial, 108 Grove Street, Worcester, MA., 01605; Mr. Bernard E. Wuthrich Pan Commercial 108 Grove Street Worcester MA. 01605; Dear Mr. Wuthrich: This is in reply to your letter of August 27, 1974 asking for clarification of the National Traffic and Motor Vehicle Safety Act.; You are correct in your impression that under section 103(d) of the Ac 'no state legislation can be more stringent than the Federal ruling.' Under paragraph S4.1.126 of Standard No. 108, effective October 14, 1974, 'a motor-driven cycle whose speed attainable in 1 mile is 30 mph or less need not be equipped with turn signal lamps.' This means that as of that date, only motor-driven cycles whose maximum speed exceeds 30 mph are required to be manufactured with turn signal lamps. Lower- speed cycles may continue to be provided with them if the manufacturer chooses, but a State cannot require him to do so. This is the result of the preemptive effect of section 103(d).; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam3636OpenMr. Patrick J. Tyler, Englander, 3429 West 47th Street, Chicago, IL 60632; Mr. Patrick J. Tyler Englander 3429 West 47th Street Chicago IL 60632; Dear Mr. Tyler: This responds to your September 8, 1982, letter asking whether mattress that you manufacture for use in a truck cab would be required to comply with Standard No. 302, *Flammability of Interior Materials*.; Standard No. 302 lists the components that are covered by the standard That list states that mattress covers must comply with the standard's requirements. The agency has interpreted the mattress cover language to mean both mattress covers and the permanent mattress ticking. Accordingly, your mattress to the extent that it is designed for use in new vehicles must comply with the requirements.; You should be aware that nothing prohibits a vehicle owner fro purchasing noncomplying equipment as replacement equipment if he so chooses. You did not indicate whether your operation is for new vehicles or replacement equipment. In the instance of noncomplying replacement equipment, no manufacturer, repair business, or distributor could install such noncomplying equipment. The installation would have to be made by the vehicle owner himself.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3375OpenMr. Carl G. F. Pedersen, Iveco Trucks of North America, Inc., P.O. Box 1102, Blue Bell, PN 19422; Mr. Carl G. F. Pedersen Iveco Trucks of North America Inc. P.O. Box 1102 Blue Bell PN 19422; Dear Mr. Pedersen: This is in reply to your letter of October 30, 1980, asking question with respect to the term 'overall vehicle width' contained in Federal Motor Vehicle Safety Standard No. 108.; You have first asked whether door handles are a part of the vehicle t be included in the definition. The answer is that they need not be included. The definition in 49 CFR 571.3(b) excludes outside rearview mirrors and other equipment items in computing 'overall vehicle width.' Although the definition does not list door handles among the equipment to be excluded in determining the nominal design dimension of the widest part of the vehicle, they are substantially similar in character to outside rearview mirrors and the other equipment items listed and may be deemed included.; Your second question is whether vehicles, whose tolerances are suc that they are less than 80 inches in overall width, must nevertheless be equipped with clearance and identification lamps if the basic vehicle design is such that the 'nominal design dimensions of the widest part of the vehicle' is 80 inches or greater. The answer is yes. If the engineering drawings, etc. of the basic vehicle design posit an overall vehicle width of 80 inches or more, all vehicles manufactured on the basis of that specification must be equipped with clearance and identification lamps even if an occasional vehicle is produced whose overall width may be slightly less than 80 inches due to the tolerances involved.; Sincerely, Frank Berndt |
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ID: aiam3286OpenMr. Tom Spencer, John Evans Mfg. Co., P.O. Box 669, Sumter, SC 29150; Mr. Tom Spencer John Evans Mfg. Co. P.O. Box 669 Sumter SC 29150; Dear Mr. Spencer: This responds to your May 6, 1980, telephone conversation with Roge Tilton of my staff in which you asked about the certification responsibilities for an incomplete trailer manufacturer. You indicated in your conversation that you manufacture chassis for trailers and supply them to final- stage manufacturers who complete them by the addition of a body. In particular, you asked whether you are required to comply with the provisions of Part 568.4, *Vehicles Manufactured in Two or More Stages*.; Part 568 places certain certification responsibilities upon incomplet vehicle manufacturers. The term 'incomplete vehicle' is defined in section 568.3, as an assemblage including, at a minimum, the frame, chassis structure, power train, steering system, suspension and braking system to the extent that these systems are to be part of the completed vehicle. If a chassis that you manufacture is completed to the extent that it has the above-listed components and merely needs the addition of a body by a final-stage manufacturer, it would be considered an incomplete vehicle and would be required to comply with the incomplete vehicle document requirements of Part 568. Please note that your incomplete trailer need not have all of the components listed above to be considered an incomplete vehicle subject to Part 558 (sic). It need only have those components in the list that will be found in the completed vehicle. Since your trailer is an incomplete vehicle but not a chassis-cab as that term is defined in Part 567, *Certification*, it would not be required to have a chassis-cab manufacturer's certification label attached to it.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam5397OpenMr. Thomas D. Turner Manager, Engineering Services Blue Bird Body Company P.O. Box 937 Fort Valley, GA 31030; Mr. Thomas D. Turner Manager Engineering Services Blue Bird Body Company P.O. Box 937 Fort Valley GA 31030; Dear Mr. Turner: This responds to your petition for rulemaking date May 31, 1994. Your petition concerns the following requirement in S5.3.3.2 of Standard No. 217, Bus Emergency Exits and Window Retention and Release: In the case of windows with one release mechanism, the mechanism shall require two force applications to open. A similar requirement is included in S5.3.3.3 for emergency roof exits. Your petition states: The requirement for two force applications to open a single release mechanism is new and unproven and in our opinion is not in the best interest of safety. NHTSA agrees that the sentence in question is susceptible to the reading you gave it. So read, this sentence imposes a requirement not intended by the agency. To avoid such unintended readings, the agency should have worded the sentence as follows: In the case of windows with one release mechanism, the exit shall require two force applications to open. The agency will issue a corrective notice in the future to make this change. Until the notice is issued, we will not take enforcement action against a manufacturer so long as a window or roof exit with one release mechanism requires two force applications to open the exit. I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam0559OpenMr. L. M. Preziosi, Division Engineering Manager, Westinghouse Specialty Lamp Division, Westinghouse Electric Corporation, One Westinghouse Plaza, Bloomfield, NJ 07003; Mr. L. M. Preziosi Division Engineering Manager Westinghouse Specialty Lamp Division Westinghouse Electric Corporation One Westinghouse Plaza Bloomfield NJ 07003; Dear Mr. Preziosi: In your letter of December 22, 1971 to Lawrence R. Schneider you as for a clarification of the relationship between 49 CFR Part 566 - *Manufacturer Identification*, and 49 CFR S 571.108, Motor Vehicle Safety Standard No. 108, *Lamps, Reflective Devices, and Associated Equipment*. Specifically you ask whether identifying information is required for miniature bulbs.; Standard No. 108 establishes performance requirements for items o motor vehicle lighting equipment, and incorporates by reference certain SAE standards that specify requirements lamps must meet in laboratory tests when assembled. The SAE standard that applies to bulbs, J573d, *Lamp Bulbs and Sealed Units*, is not incorporated by reference, and Standard No. 108 contains no requirements for the output of bulbs furnished with a lamp assembly. When a lamp is tested for conformity, the production bulb is removed and a calibrated bulb substituted, in accordance with Paragraph C of SAE Standard J575d, *Tests for Motor Vehicle Lighting Devices and Components*, the test bulb is to be 'representative of standard bulbs in regular production' and must be 'selected for accuracy in accordance with specifications listed in . . . SAE J573.'; In summary, Standard No. 108 does not specify performance requirement for lamp bulbs, and production bulbs are not used in lamp testing. Therefore, Standard No. 108 does not apply to bulbs and bulb manufacturers are not required to certify conformance to Federal standards, or to submit information pursuant to the *Manufacturer Identification* regulations.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0968OpenMr. James E. Bates, Executive Director, Fire Equipment Manufacturers' Association, Inc., 604 Davis Street, Evanston, IL 60204; Mr. James E. Bates Executive Director Fire Equipment Manufacturers' Association Inc. 604 Davis Street Evanston IL 60204; Dear Mr. Bates: This is in reply to your letter of December 22 to Mr. Lew Owen of thi Office concerning definitions of mobile homes, motor homes, and recreational vehicles.; For our purposes, mobile homes are regarded as mobile structur trailers. A trailer is 'a motor vehicle with or without motive power, designed for carrying persons or property and for being drawn by another motor vehicle.' A mobile structure trailer is 'a trailer that has a roof and walls, is at least 10 feet wide, and can be used off-road for dwelling or commercial purposes.'; Motor homes are regarded as multi-purpose passenger vehicles, which ar defined as 'a motor vehicle with motive power, except a trailer, designed to carry 10 persons or less which is constructed either on a truck chassis or with special features for occasional off- road operation.'; We have no definition for 'recreational vehicle.' Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam3365OpenMr. Robert A. Belcher, President, Coded Electronics Corporation, 1239 Taylor, San Francisco, CA 94108; Mr. Robert A. Belcher President Coded Electronics Corporation 1239 Taylor San Francisco CA 94108; Dear Mr. Belcher: This is in reply to your letter of August 20, 1980 asking whether you emergency hazard signaling system conforms with Federal Motor Vehicle Safety Standard No. 108. You also asked as to the steps necessary to make it mandatory.; From the specifications provided in your letter, it appears that bot modes of operation (hazard and distress) would comply with the flash rates and the percent of current 'on' time required by SAE J945, the standard for hazard warning signal flashers incorporated by reference in Standard No. 108. If your device meets all other requirements of SAE J945 and SAE J910, the standard for hazard warning signal operating units also incorporated by reference, it should comply with Standard No. 108.; I am enclosing a copy of 49 CFR Part 552, setting forth the procedure under which you may petition for an amendment of Standard No. 108 that would require a distress signaling system on vehicles.; Sincerely, Frank Berndt, 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.