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: aiam0653OpenMr. Heinz W. Gerth, Assistant Vice President, Mercedes-Benz of North America, Inc., 158 Linwood Plaza, Fort Lee, NJ 07028; Mr. Heinz W. Gerth Assistant Vice President Mercedes-Benz of North America Inc. 158 Linwood Plaza Fort Lee NJ 07028; Dear Mr. Gerth:#On November 9, 1971, you wrote concerning th requirement in Standard No. 101 that a control be provided to adjust the intensity of control illumination, continuously variable from an 'off' position to a position providing illumination sufficient for the vehicle operator to readily identify controls under conditions of reduced visibility. You asked an interpretation that 'the term 'off' means a control position which provides minimal control illumination which is not distracting to the driver who has adapted to dark ambient roadway conditions.'#In our opinion, the word 'off' means a control position providing no illumination, and we therefore do not concur in your interpretation. You have asked, however, as an alternative, that your letter be considered as a petition for rulemaking to amend Standard No. 101 to provide an option permitting the type of control already incorporated in Mercedes-Benz vehicles.' We have tentatively determined that your petition has merit, and that quantitative levels for control illumination intensity should be established in Standard No. 101. We shall therefore initiate appropriate rulemaking with a proposed effective date of September 1, 1973.#Sincerely, Douglas W. Toms, Administrator; |
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ID: aiam3284OpenCharles M. Kneip, Vehicle Services Division, Department of Motor Vehicles, Lincoln, NE 68509; Charles M. Kneip Vehicle Services Division Department of Motor Vehicles Lincoln NE 68509; Dear Mr. Kneip: This is in response to your letter of May 7, 1980, in which you aske whether the proposed Nebraska certificate of title may be used as a substitute for the Federal odometer disclosure form required by 49 CFR Part 580.; The Nebraska title differs from the minimum Federal requirements i that there is no certification that the odometer reading reflects the actual mileage or the mileage over 99,999 miles, or is not the actual mileage. The buyer is not required to sign the Nebraska title as he is the Federal form (sic). In addition, your title does not refer to the legal consequences of a false disclosure. If you can make these additions, the Nebraska title will satisfy the Federal requirements.; For your information, I have enclosed a copy of the *Federal Register notice which discusses the short form odometer disclosure that States may use on their titles to satisfy Federal requirements, a letter to Maryland in which we indicate that formal approval by NHTSA is not necessary if the title contains the specified information, and sample titles that the NHTSA has approved.; If you need any further inforamtion, please do not hesitate to contac us.; Sincerely, John Womack, Assistant Chief Counsel |
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ID: aiam3195OpenMr. Brian Gill, Manager, Certification Department, American Honda Motor Co., Inc., P.O. Box 50, 100 W. Alondra Boulevard, Gardena, California 90247; Mr. Brian Gill Manager Certification Department American Honda Motor Co. Inc. P.O. Box 50 100 W. Alondra Boulevard Gardena California 90247; Dear Mr. Gill: This is in response to your letter of November 18, 1979, requesting a interpretation as to whether the VIN plate samples you enclosed with your letter comply with the requirements of Standard No. 115, *Vehicle identification number*.; You enclosed two proposed VIN plates in your letter, one fo automobiles and one for motorcycles.The VIN plates themselves and the pre-printed lettering which appears on them seem to conform to the requirement of Standard No. 115. The lettering is clear and indelible, as required by S4.3, in that it cannot be removed without damage to the surface on which it is printed. Further, the plate when riveted to the vehicle would be considered to be permanently affixed in that it cannot be removed without damage (S4.3). The type face utilized for the lettering consists of capital, sans serif characters with a minimum height of 4 mm as required by S4.3.1.; The letters stamped on the automobile VIN plate 'SL5322AS000001', ca hardly be seen, and would not appear to meet the requirements of S4.3 and S4.4.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1829OpenHonorable Mark Andrews, House of Representatives, Washington, DC 20515; Honorable Mark Andrews House of Representatives Washington DC 20515; Dear Mr. Andrews: This responds to your February 18, 1975, request for information i behalf of a constituent, concerning any Federal regulation which might require bulk oil trucks to have a 120-inch wheelbase and be equipped with certain wheels, tires, and axles.; Neither the National Highway Traffic Safety Administration (NHTSA) no the Bureau of Motor Carrier Safety of the Federal Highway Administration has issued a safety standard which requires a certain wheelbase or the components listed by your constituent.; NHTSA has issued Standard No. 121, *Air brake systems*, whic establishes minimum performance requirements for air-braked vehicles. A major requirement is that an air-braked vehicle must be capable of stopping within a distance that is comparable to average passenger car performance. This requirement is intended to reduce the incompatibility in braking performance between heavy trucks and passenger cars which must share the nation's highways.; Manufacturers are free to choose any design which permits thei vehicles to stop in the required distance. It is possible that the manufacturer of your constituent's vehicle has found that a longer wheelbase and stronger axles, brakes, wheels, and tires are necessary to insure that the vehicle is capable of consistently stopping without loss of control in a distance comparable to the average passenger car. We consider the modification of vehicles in this fashion to be a significant contribution to motor vehicle safety.; Sincerely, James C. Schultz, Chief Counsel |
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ID: aiam0351OpenMr. Martin Rothfield, Manager, Quality Assurance, Ideal Corporation, 435 Liberty Avenue, Brooklyn, NY, 11207; Mr. Martin Rothfield Manager Quality Assurance Ideal Corporation 435 Liberty Avenue Brooklyn NY 11207; Dear Mr. Rothfield: In your letter of May 4, 1971, to Francis Armstrong you reques permission to conduct testing of turn signal and hazard warning signal flashers pursuant to SAE Standard J823b, 'Flasher Test Equipment,' April 1968.; Federal Motor Vehicle Safety Standard No. 108 incorporates by referenc SAE Standard J590b, 'Automotive Turn Signal Flashers,' October 1965, and SAE Recommended Practice J945, 'Vehicular Hazard Warning Signal Flasher,' February 1966, both of which specify test circuitry and equipment according to 'SAE J823.' It is my understanding that the major difference between J823 and J823b, which becomes the appropriate sub-referenced standard on January 1, 1972, is the specification in the latter that 'The required voltage tests [for variable-load flashers] with maximum bulb load shall be conducted without readjusting each corresponding power supply voltage, previously set with minimum bulb load.' It appears that J823 was written before variable load flashers were in general use and that this is the reason for omission of this specification from J823. Since J823b includes all the requirements of the presently referenced SAE standard, you may proceed to implement it immediately.; Sincerely, Robert L. Carter, Acting Associate Administrator, Moto Vehicle Programs; |
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ID: aiam4095OpenMr. Earnest Farmer, Director of Pupil Transportation, Tennessee Department of Education, Nashville, TN 37219-5335; Mr. Earnest Farmer Director of Pupil Transportation Tennessee Department of Education Nashville TN 37219-5335; Dear Mr. Farmer: This responds to your February 19, 1986 letter to the National Highwa Traffic Safety Administration (NHTSA) asking whether Federal motor vehicle safety standards prohibit commercial businesses from using fiberglass on the exterior of school buses. As explained below, the answer to your question is no.; The National Traffic and Motor Vehicle Safety Act authorizes NHTSA t issue minimum performance standards for school buses. Our safety standards do not specify the materials to be used for the exterior of school buses. However, the materials chosen by a manufacturer must be strong enough to enable the bus to meet the requirements of those standards. Among those requirements are the rollover protection ones of Standard No. 220, fuel system requirements of Standard No. 301, and strength requirements of Standard No. 221, *School Bus Body Joint Strength*, for body panel joints on school buses with gross vehicle weight ratings over 10,000 pounds. Manufacturers of new school buses using fiberglass for school bus exteriors must certify that their vehicles conform to the requirements of all applicable school bus safety standards.; I hope this information is helpful. Please contact my office if yo have further questions.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam0472OpenMr. H. A. Sage, Director of Research and Engineering, Truck- Lite Company, P. O. Box 387, Jamestown, NY, 14701; Mr. H. A. Sage Director of Research and Engineering Truck- Lite Company P. O. Box 387 Jamestown NY 14701; Dear Mr. Sage: This is in reply to your letter of October 14, 1971, to Mr. Lewis Owe of this Office concerning an interpretation regarding your Truck-Lite No. 127 license plate light.; The requested interpretation concerns the 8 degree incident light angl specified in SAE J587, 'License Plate Lamps,' as follows:; >>>'When a single lamp is used to illuminate the plate, the lamp an license plate holder shall bear such relation to each other that at no point on the plate will the incident light make an angle of less than 8 deg to the plane of the plate.'<<<; Since the 8 degree incident light angle is also a requirement o Federal Motor Vehicle Safety Standard No. 108, all license plate lamp designs must conform to it. It is our position that the angle be measured from the optical center of the lens, therefore, the Electrical Testing Laboratories' position is valid. That is, the incident light angle of your lamp, without the paint shield and when mounted as it will be installed on the vehicle, is below the 8 degree minimum requirement.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam0167OpenMr. W. D. Beamer, General Claim Agent, The Cleveland, Columbus, and Cincinnati Highway, Inc., 213 Euclid Avenue, Cleveland, OH 44114; Mr. W. D. Beamer General Claim Agent The Cleveland Columbus and Cincinnati Highway Inc. 213 Euclid Avenue Cleveland OH 44114; Dear Mr. Beamer: Your letter of June 17, 1969, to Mr. Donald Morrison of the Bureau o Motor Carrier Safety, concerning switching arrangements for running lamps, has been transferred to this Office for consideration and reply.; Enclosed for your information is a copy of Federal Motor Vehicle Safet Standard No. 108 on lighting requirements for motor vehicles. This standard is applicable to new vehicles manufactured on or after the effective date of January 1, 1969. Special wiring requirements, such as lamp switching arrangements, are included in paragraphs S3.4 through S3.4.7 of the standard.; We do not completely understand your usage of the term 'runnin lights.' If you are referring only to tail lamps, your attention is invited specifically to paragraph S3.4.3 of the standard which is quoted as follows: 'As a minimum the tail lamps shall be illuminated when the headlamps are illuminated except when the headlamps are being flashed.' The switching arrangements for other 'running lights,' such as clearance lamps and identification lamps, are at the option of the vehicle manufacturer.; Thank you for writing. Sincerely, Charles A. Baker, Office of Standards on Accident Avoidance Motor Vehicle Safety Performance Service; |
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ID: aiam0262OpenMr. Gerald Sagerman, U.S. Agent, TVR Engineering, Ltd., 572 Merrick Road, Lynbrook, NY 11563; Mr. Gerald Sagerman U.S. Agent TVR Engineering Ltd. 572 Merrick Road Lynbrook NY 11563; Dear Mr. Sagerman: This is in response to your letter of October 14, 1970, to the Directo of the National Highway Safety Bureau forwarding information sheets on the TVR Vixen. I am enclosing copies of the Bureau's Consumer Information Regulations (49 CFR Part 575). The substantive provisions, S 575.101 on vehicle stopping distance, S 575.102 on tire reserve load, and S 575.106 on acceleration and passing ability, require the furnishing of specific information in a format which is in the form set out in the regulations. The information sheets which you have provided fall short of these requirements in both form and substance. For example, S 575.101 requires furnishing information on the minimum stopping distance, expressed in feet, for the particular vehicle, from a particular speed, at specified loads, with the braking system in a specified condition. The information provided by you in this regard is incomplete, and is not in the form specified. In addition, the regulations require the information to describe and be valid for each of the vehicles with which it is provided.; Please study the enclosed regulations carefully and forward to u complying consumer information within the near future. Let us know if you need further assistance.; Sincerely, Rodolfo A. Diaz, Acting Associate Director, Motor Vehicl Programs; |
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ID: aiam1683OpenMr. Jeffrey B. Lugash, Suite 2200, 1801 Century Park East, Los Angeles, California 90067; Mr. Jeffrey B. Lugash Suite 2200 1801 Century Park East Los Angeles California 90067; Dear Mr. Lugash: This responds to your October 30, 1974, questions whether th Department of Transportation or any 'private establishment' requires manufacturers to file specifications for automobile, motorcycle, and airplane tires, whether Standard No. 119, *New pneumatic tires for vehicles other than passenger cars*, lists these specifications, and what the number '222474 7MRR' means on the bead of a motorcycle tire.; The Department of Transportation's National Highway Traffic Safet Administration has issued Standard No. 119 (effective March 1, 1975), which establishes minimum performance and labeling requirements with which the manufacturer must comply. A copy of the standard is enclosed. Certain tire specifications must appear on the sidewall, and certain rim-matching specifications must be published by the manufacturer or appear in a publication of at least one private tire organization.; It is the general practice of the tire industry to list specification of tires in a private publication, such as the 'Year Book' of the Tire and Rim Association in the United States. Their address is: The tire and Rim Association, Inc., 3200 West Market Street, Akron, Ohio 44313.; The NHTSA Tire and Wheel Division has determined that the number whic you cite is of significance only to the manufacturer of the tire.; Yours truly, Richard B. Dyson, Acting 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.