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: 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: 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: 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: 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: aiam1744OpenMr. J. W. Kennebeck, Manager, Emissions, Safety & Development Dept., Volkswagen of America, Inc., Englewood Cliffs, NJ 07632; Mr. J. W. Kennebeck Manager Emissions Safety & Development Dept. Volkswagen of America Inc. Englewood Cliffs NJ 07632; Dear Mr. Kennebeck: This responds to Volkswagen's December 11, 1974, request fo confirmation that the deletion of the ignition interlock requirement from Standard No. 208, *Occupant crash protection*, does not have the effect of prohibiting installation of an interlock device in a vehicle which meets the requirements of S4.1.2.; Volkswagen will utilize a passive belt system in satisfaction of th requirements of S4.1.2. Passive belts are subject to specific belt assembly requirements of S4.5.3.3. These requirements were recently modified by deletion of the requirement for a belt interlock system (39 FR 38380, October 31, 1974), and passive belt assemblies must now conform to S7.1 (Adjustment), S7.2 (Latch mechanism), and S7.3 (Seat belt warning system).; Your interpretation of these requirements is correct. The Federal moto vehicle safety standards are minimum performance requirements with which each vehicle to which they are applicable must comply. They do not, however, prohibit installation of additional safety devices. As a practical matter, of course, additional devices could not be installed if that installation had the effect of causing the required systems not to comply.; The NHTSA agrees than (sic) an interlock system is important fo ensuring use of a passive belt system.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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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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ID: aiam1529OpenMr. Beller,Alfred Teves GMBH,6 Frankfurt/Main 2,Postfach 119155, Germany; Mr. Beller Alfred Teves GMBH 6 Frankfurt/Main 2 Postfach 119155 Germany; Dear Mr. Beller:#This responds to your May 10, 1974, request fo permission to stamp label information on hose assemblies in place of banding, and to reduce S9.2.5 burst pressure from 350 to 100 psi, and your further request for an interpretation of the status of an inline check valve as part of a vacuum brake hose.#The inline check valve is not subject to Standard No. 106, *Brake hose*, as a brake hose end fitting. In this configuration, the couplers depicted in your drawing are the clamps, and the check valve is a separate component to which the hose assemblies are attached.#The issue of stamping instead of banding will be answered in our upcoming Notice 11 in response to petitions for reconsideration of the brake hose standard.#Your petition for a reduction in the burst strength requirement for vacuum hoses is denied. The minimum burst pressure of 350 psi was established by the Society of Automotive Engineers in 1942, taking into consideration the effects of backfire pressure and the severe underhood environment to which vacuum hose may be exposed. Hoses with this burst pressure have provided excellent reliability and durability. We have no data to justify a reduction in burst strength in view of the two hazards just cited.#Sincerely,Robert L. Carter,Associate Administrator,Motor Vehicle Programs; |
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ID: aiam2866OpenMr. Robert B. Kurre, Director of Engineering, Wayne Corporation, P. O. Box 1447, Industries Road, Richmond, IN 47374; Mr. Robert B. Kurre Director of Engineering Wayne Corporation P. O. Box 1447 Industries Road Richmond IN 47374; Dear Mr. Kurre: This responds to your recent letter asking whether Safety Standard No 208, *Occupant Crash Protection*, does require side- facing seats in multipurpose passenger vehicles to comply with one of the options under paragraph S4.2.2, since the side-facing seats in question would be considered designated seating positions. If a manufacturer chooses to install seat belts under one of the options of that paragraph, the seat belt assemblies must comply with Safety Standard No. 209, *Seat Belt Assemblies*, and Safety Standard No. 210, *Seat Belt Anchorages*.; Safety Standard No. 210 does exempt side-facing seats from its strengt requirements, but all other requirements of the standard would be applicable. However, we strongly recommend that belt anchorages for side-facing seats be of at least equivalent strength to anchorages for forward and rearward facing seats, since the strength specifications are only minimum performance requirements. Side-facing seats were excepted from the strength requirements specified in the standard because the forces acting on side-facing seats are different from those acting on forward or rearward facing seats and the requirements and procedures were specifically developed for these latter seats.; Please contact this office if you have any further questions. Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3790OpenMr. A. J. DiMaggio, Manager, Gov. and Customer Relations, The Firestone Tire & Rubber Co., 1200 Firestone Parkway, Akron, OH 44317; Mr. A. J. DiMaggio Manager Gov. and Customer Relations The Firestone Tire & Rubber Co. 1200 Firestone Parkway Akron OH 44317; Dear Mr. DiMaggio: This is in reply to your letter of December 8, 1983, to th Administrator, petitioning for a determination that a noncompliance with Motor Vehicle Safety Standard No. 117, *Retreaded Pneumatic Tires*, be deemed inconsequential as it relates to motor vehicle safety.; The noncompliance consists of omission of the 'DOT' certificatio symbol. You have represented that tires so affected nevertheless meet Standard No. 117 in all other respects.; It has been the policy of this agency since 1977 to treat omissions o the DOT symbol as failures to certify pursuant to Sections 114 and 108(a)(1)(C) of the National Traffic and Motor Vehicle Safety Act rather than as failures to comply with the Federal motor vehicle safety standard that requires or allows that method of certification. The symbol is not considered to establish a minimum standard of motor vehicle performance. This means that manufacturers who fail to provide the symbol are not required to conduct a notification and remedy campaign, and that accordingly the National Highway Traffic Safety Administration is not required to publish notices of petitions requesting inconsequentiality determinations.; Your petition is therefore moot. Thank you for bringing this matter t our attention.; 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.