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: aiam2121OpenMr. J. C. Eckhold, Director, Automotive Safety Office, Ford Motor Company, The American Road, Dearborn, MI 48121; Mr. J. C. Eckhold Director Automotive Safety Office Ford Motor Company The American Road Dearborn MI 48121; Dear Mr. Eckhold: This responds to your letter of November 11, 1975, requestin confirmation that a 1976 Ford Motor Company 'deluxe continuous-loop seat belt system' satisfies the requirements of Section 7.1.1 of Standard No. 208, *Occupant Crash Protection*.; Section 7.1.1 requires adjustment of the lap belt portion of a fron outboard seat belt assembly 'by means of an emergency-locking or automatic-locking retractor' and adjustment in most cases of the upper torso portion 'by means of an emergency-locking retractor.' The language permits some single retractor, continuous loop systems as long as the single retractor does 'automatically adjust' the tension of the lap belt portion to prevent excessive slack. Because of the submarining danger of a slack lap belt, the National Highway Traffic Safety Administration (NHTSA) has restricted the acceptability of continuous loop systems under S7.1.1 in two areas.; In the NHTSA's September 25, 1972, letter to Renault to which yo refer, the level of friction in the tongue is discussed and our position is stated that it must have a sufficiently low level to qualify the lap belt portion as 'automatically adjustable.' In your recent demonstration of the tongue frictions in the Ford 1976 'standard' and 'deluxe' continuous loop seat belt systems to NHTSA personnel, we saw no evidence of design deficiency in limited use of those systems.; The other restriction concerns the use of manual and automatic tensio relieving devices on the upper portion of continuous loop systems. In our letters of March 9, 1973, and March 27, 1975 (to General Motors), June 13, 1975 (to Chrysler Corporation), and September 5, 1975 (to Takata-Kojyo), the NHTSA has limited the use of tension relieving devices to the upper torso portion of seat belt assemblies that have 'an individually adjustable lap belt.' It is our view that the 1976 Ford deluxe continuous loop system does not have 'an individually adjustable lap belt' within the meaning of Standard No. 208. In this system slack which is introduced into the continuous loop by the 'window shade' tension relief device on the upper retractor is directly transferred to the lap belt, thus increasing the risk of submarining if a crash should occur. I would like to point out that issues related to tension relief devices are, however, still outstanding in an (sic) NHTSA proposal (Docket 74-32, Notice 1).; I am enclosing a report on 'Comfort and Convenience Analysis o Advanced Restraint Systems' of August 1975. This study, conducted by the NHTSA Safety Research Laboratory on a number of different safety belt designs concludes that: 'Several aspects of the systems caused difficulties or confusion, but the single-loop 'window-shade' feature most frequently produced problems.' In light of our mutual desire to improve safety belt usage levels, I should also like to again recommend to your attention the results of the earlier NHTSA sponsored study 'Sources and Remedies for Restraint System Discomfort and Inconveniences' by Man Factors, Inc., that I sent to your company in January 1975.; Sincerely, James B. Gregory, Administrator |
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ID: aiam2571OpenMr. Jim Beach, Collins Industries, Inc., Box 58, Hutchinson, KS 67501; Mr. Jim Beach Collins Industries Inc. Box 58 Hutchinson KS 67501; Dear Mr. Beach: This confirms your April 19, 1977, conversation with Roger Tilton of m staff concerning the definition of school bus.; The National Highway Traffic Safety Administration (NHTSA) define school bus in a notice issued on December 31, 1975 (40 FR 60033) to mean 'a bus that is sold, or introduced into interstate commerce, for purposes that include carrying students to and from school or related events, but does not include a bus designed and sold for operation as a common carrier in urban transportation.' This definition incorporates by reference the definition of bus (49 CFR Part 571.3) which is 'a motor vehicle with motive power, except a trailer, designed for carrying more than 10 persons.' Therefore, by definition a school bus is a vehicle that carries more than 10 persons (e.g., 10 passengers and a driver). This does not preclude smaller vehicles from transporting school children. Vehicles carrying 10 or fewer persons would not have to comply with the school bus construction requirements.; I am enclosing a copy of the notice that established the school bu definition. If you have further questions, do not hesitate to contact us.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam3730OpenMr. C. B. Bright, Jr., C. B. Bright Motor Co., Route 1, Ashland, MS 38603; Mr. C. B. Bright Jr. C. B. Bright Motor Co. Route 1 Ashland MS 38603; Dear Mr. Bright: This is in reply to your letter of July 19, 1983, to Mr. Vinson of thi office. You have asked whether you are violating any Federal standards or regulations by adding 'right side steering, accelerator, brakes & turn signal controls to rural mail carriers delivery vehicles (cars, pickup, jeeps, etc.).' You have told us that you do not modify in any way the left hand side controls with which the vehicle was originally equipped.; Assuming that your modifications do not affect the performance of an of the systems with which the vehicle was equipped by its original manufacturer, your conversion operations would not be prohibited by the National Traffic and Motor Vehicle Safety Act. However, with respect to any new vehicle that you modify which has not yet reached its first purchaser for purposes other than resale, you are required to affix a label identifying you as the alterer and certifying that the vehicle as altered meets all applicable Federal motor vehicle safety standards. This is required by Title 49 Code of Federal Regulations, Section 567.7. I enclose a copy of Part 567 for your information.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2822OpenMs. LaVerne L. Kruckenberg, Engineer, Highway Manufacturing Company, P.O. Box 256, Edgerton, WI 53534; Ms. LaVerne L. Kruckenberg Engineer Highway Manufacturing Company P.O. Box 256 Edgerton WI 53534; Dear Ms. Kruckenberg: This is in reply to your letter of March 1, 1978, to Mr. Vinson of thi office asking whether marker lamps on your new 'bevel designed front Van Trailer' comply with Federal Motor Vehicle Safety Standard No. 108. Specifically, instead of providing two amber clearance lamps, on the trailer front and two amber side marker lamps at the trailer's leading edge, you would install a combination clearance-side marker lamp at 45 degrees on the beveled leading edge of the trailer.; Paragraph S4.4.1 of Standard No. 108 permits a side marker lamp to b combined with a clearance lamp 'if the requirements for each lamp...are met....' This means that the combination lamp in position on the vehicle must meet the requirements of SAE Standard J592e, *Clearance, Side Marker, and Identification Lamps*, July 1972. This standard addresses specific photometric requirements for combination clearance and side marker lamps and I enclose a copy for your information.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3360OpenJohn Kelly, Iowa Department of Transporation (sic), Office of Motor Vehicle Enforcement, 5238 N.W. Second Avenue, Des Moines, IA 50313; John Kelly Iowa Department of Transporation (sic) Office of Motor Vehicle Enforcement 5238 N.W. Second Avenue Des Moines IA 50313; Dear Mr. Kelly: This is in response to your letter of August 29, 1980, in which yo requested our opinion on the odometer disclosure required to be made for reconstructed vehicles. The purpose of the odometer reading is to represent the mileage that a vehicle has travelled. If a vehicle is reconstructed with an older chassis and a new body, then it is the opinion of the National Highway Traffic Safety Administration that the odometer should reflect the mileage travelled by the chassis. Purchasers rely on the odometer as an indication of the safety, reliability, and value of a vehicle. If the mileage which the chassis has been driven is not provided to the purchaser, he could be led into a false sense of security, neglecting needed repairs or inspections. The odometer should therefore be set to the mileage travelled by the chassis. If the odometer is incapable of being set to that mileage, it should be set at zero and a written notice should be placed in the left door frame of the vehicle, specifying the mileage the chassis has been driven and the date the new odometer was installed. If the person who asembles the vehicle does not know the mileage the chassis has been driven, he should state that the mileage is not accurate and should not be relied upon.; Likewise, if a vehicle is constructed from the parts of severa vehicles, the odometer statement must still be completed at the time of sale. If the seller knows the mileage on the various components used to construct the vehicle, he should inform the purchaser of the highest mileage that he knows, or the mileage on the chassis if he knows it. If he does not know the mileage, he will be required to state that the mileage is not accurate and should not be relied upon. This applies to all major mechanical and structural portions of the vehicle and not to items that are replaced periodically such as tires.; You also asked if there are any specifications on three wheel vehicle and homemade mopeds. Section 571.3 of Title 49 of the Code of Federal Regulations defines 'motorcycle' as a 'motor vehicle with motive power having a seat or a saddle for the use of the rider and designed to travel on not more than three wheels in contact with the ground.' The vehicle described in the article which you attached to your letter and mopeds fall iwthin this category and the applicable motor vehicle safety standards would apply. Any homemade vehicle, whether a moped or other vehicle, which is driven on the public roads must comply with the applicable safety standards. For your information, I have enclosed a pamphlet which described the existing safety standards and specifies which vehicles must comply with those standards. The standards for motorcycles would apply the vehicles described above.; If you have any further questions, please do not hesitate to write. Sincerely, John Womack, Assistant Chief Counsel |
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ID: aiam2988OpenMr. Moe Pare, Jr., Director of Design, Cars & Concepts, Inc., 12500 E. Grand River, Brighton, MI 48116; Mr. Moe Pare Jr. Director of Design Cars & Concepts Inc. 12500 E. Grand River Brighton MI 48116; Dear Mr. Pare: This responds to your March 2, 1979, letter concerning the definitio of the vehicle sub-classification, 'convertible.' Your letter included several Figures of various vehicle designs and asked whether each would be considered a 'convertible' by the National Highway Traffic Safety Administration.; While our regulations do not include a formal definition o 'convertible,' the agency has stated that it considers a convertible to be a vehicle whose 'A' pillar or windshield peripheral support is not joined with the 'B' pillar (or rear roof support rearward of the 'B' pillar position) by a fixed rigid structural member. Therefore, passenger cars equipped with a 'sun roof' or a 'Hurst hatch roof' do not qualify as convertibles, because they have a fixed, rigid structural member in the described location (April 21, 1976, letter of interpretation enclosed). This interpretation applies, moreover, whether the rigid structural member joining the 'A' and 'B' pillars is a hidden reinforcing component or whether the structural member is part of the exterior roof panel.; Given this interpretation, only the Fiat X-19 vehicle desig illustrated in your Figure 5 would qualify as a 'convertible.' Each vehicle design in your other illustrations (Figures 1, 2, 3, 4, 6, 7, 8 and 9) include fixed, rigid structural components joining the 'A' and 'B' pillar sections of the vehicles and, therefore, would not be classified as convertibles. Likewise, the designs would not be considered 'open-body type vehicles' (49 CFR 571.3) for the same reason, the structural member, whether hidden or not, would be considered part of the vehicle top. also, I would point out that the 'open-body vehicle' designation generally refers to multi-purpose passenger vehicles such as 'Jeeps' or 'dune buggies.'; I hope this clarification is responsive to your inquiry. If you hav any further questions please contact Hugh Oates of my office (202-426-2992).; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam1648OpenMr. John C. Hansen, Sales Manager, Columbia Body & Equipment Co., 123 N. E. Oregon Street, Portland, OR 97232; Mr. John C. Hansen Sales Manager Columbia Body & Equipment Co. 123 N. E. Oregon Street Portland OR 97232; Dear Mr. Hansen: This responds to CBE's October 24, 1974, question whether a traile equipped with a telescoping drawbar that varies the distance between axles to conform to various State regulations would qualify as a 'Heavy hauler trailer' as that term is defined in Standard No. 121, *Air brake systems*:; >>>'Heavy hauler trailer' means a trailer with one or more of th following characteristics:; (1) Its brake lines are designed to adapt to separation or extension o the vehicle frame, or; (2) Its body consists only of a platform whose primary cargo-carryin surface is not more than 40 inches above the ground in an unloaded condition, except that it may include sides that are designed to be easily removable and a permanent 'front-end structure' as that term is used in S 393.106 of this title.<<<; The answer to your question is no. The extension of the drawbar is no an 'extension of the vehicle frame.' This characteristic is intended only to describe trailers whose function necessitates a highly specialized configuration that significantly interferes with brake design. In contrast the telescoping drawbar is not related to the trailer's function, but simply permits the vehicle to conform to State highway regulations.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam3675OpenSherrod Vans, Inc., 9485 Regency Square Blvd., Suite 330, Jacksonville, FL 32211; Sherrod Vans Inc. 9485 Regency Square Blvd. Suite 330 Jacksonville FL 32211; Dear Sirs: This responds to your recent letter asking for confirmation that you d not have to install seat belts on a sofa/bed used in your van conversions if you place a 'disclaimer' on the sofa to indicate that it is not to be considered a seat while the vehicle is in motion.; Your assumption is incorrect. You must install seat belts on these sof seats. Safety Standard No. 208, *Occupant Crash Protection*, requires the installation of either Type 1 (lap belts) or Type 2 (combination lap and shoulder belts) belts at each designated seating position in a van, including rear-most seats. Under 49 CFR Part 571.3, 'designated seating position' is defined as,; >>>'any plan view location capable of accommodating a person at leas as large as a 5th percentile adult female, if the overall seat configuration and design and vehicle design is such that the position is likely to be used as a seating position while the vehicle is in motion, except for auxiliary seating accommodations such as temporary or folding jump seats. Any bench or split-bench seat in a passenger car, truck or multi-purpose passenger vehicle with a GVWR less than 10,000 pounds, having greater than 50 inches of hip room (measured in accordance with SAE Standard J1100(a)) shall have not less than three designated seating positions, unless the seat design or vehicle design is such that the center position cannot be used for seating.'<<<; In our opinion, a sofa seat in the rear of a van is likely to be use as a seating position while the vehicle is in motion and, therefore, is a designated seating position. The fact that the seat converts to a bed is irrelevant. This will not prevent passengers from using the position for seating when the accommodation is in its unconverted, sofa mode.; A manufacturer cannot escape the responsibilities associated with designated seating position simply by placing a sticker on the seat disclaiming that the position is to be used. If this were the case, manufacturers would be able to place stickers on all seats in vehicles and avoid the requirements for seat belts entirely. It is true that Safety Standard No. 207, *Seating Systems*, requires seats not designated for occupancy while the vehicle is in motion to be conspicuously labeled to that effect (paragraph S4.4). However, this labeling requirement is only applicable to positions that do not qualify as designated seating positions under 49 CFR 571.3. For example, folding jump seats are not considered designated seating positions under the definition. Therefore, these seats should be labeled as required by Standard No. 207.; In our opinion, you would be able to omit seat belts in this case onl if the structure was a permanent, stationary bed which could not be converted into a sofa. Also, please note that under the definition of designated seating position, you would be required to install at least three sets of seat belts if the sofa has hip room greater than 50 inches.; I hope this has eliminated any misunderstanding you may have ha concerning this matter. If you have any further questions, please contact Hugh Oates of my staff (202-426-2992).; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2967OpenMr. Carmen D. DeLeone, President, Derbi Motor Corporation of America, 23011 Alcalde Drive, Suite A, Laguna Hills, California 92653; Mr. Carmen D. DeLeone President Derbi Motor Corporation of America 23011 Alcalde Drive Suite A Laguna Hills California 92653; Dear Mr. DeLeone: This is in reply to your letter of January 29, 1979, asking for a interpretation of Federal Motor Vehicle Safety Standard No. 123, *Motorcycle Controls and Displays*, as it pertains to Derbi Variant Mopeds. you have asked whether the Derbi's manual fuel shut-off control meets the requirements of the standard.; Table 1 of the standard specifies the location and method of operatio of the equipment items listed therein. For the manual shut-off control (Item 7), no location is specified. The method of operation set forth, however, is that the control must point forward to indicate 'Off,' downward for 'On,' and upward for 'Reserve' (if provided). This requirements appears intended for a control mounted vertically, such as on the side of the vehicle. A standardized operating method for a vertical mounted control is in the interest of safety since the operator will not be able to read its legends while seated at the primary controls.; "However, on the Derbi, the manual fuel shut-off control is mounte horizontally on the frame connecting the front and rear parts of the machine and in a position that appears to be visible to an operator seated at the controls. You have attempted to identify j it in the manner specified by the standard. We are of the opinion that, until Standard No. 123 specifies that the control be vertically mounted, the Derbi control may be located and identified as you have depicted it."; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam1218OpenMr. D. Black, Technical Director, Alfa Romeo, Inc., 250 Sylvan Avenue, Englewood Cliffs, NJ 07632; Mr. D. Black Technical Director Alfa Romeo Inc. 250 Sylvan Avenue Englewood Cliffs NJ 07632; Dear Mr. Black: This is in response to your letter of August 9, 1973, in which yo inquire whether Alfa Romeo may add to the consumer information 'handouts' for prospective purchasers, required by NHTSA regulations, the consumer information required by the Environmental Protection Agency.; As long as the information required by NHTSA is presented in conformit with 49 CFR Part 575, we have no objection to the inclusion within the same covers of additional information relative to EPA requirements.; The wall posters you mentioned are not required by our regulations, s you may do with them as you please.; Sincerely, Lawrence R. Schneider, 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.