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 |
|---|---|
| search results table | |
ID: aiam0450OpenMr. Paul H. Lawrenz, American Motors Corporation, 14250 Plymouth Road, Detroit, MI 48232; Mr. Paul H. Lawrenz American Motors Corporation 14250 Plymouth Road Detroit MI 48232; Dear Mr. Lawrenz: This is in reply to your letter of September 21, 1971, to Mr. Lewis C Owen of this Office concerning an interpretation on the visibility requirements in FMVSS No. 108 as referenced in FMVSS No. 215.; Paragraph S4.3.1.1 of FMVSS No. 108 requires that the lamps be visibl at the extreme photometric test angles or as otherwise specified in the applicable SAE Standards. This paragraph does not require photometric tests at these extreme angles.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
|
ID: aiam4413OpenD. F. Landers, PSI Mobile Products Inc., 25 Eldredge, P.O. Box 1183, Mt. Clemens, MI 48043; D. F. Landers PSI Mobile Products Inc. 25 Eldredge P.O. Box 1183 Mt. Clemens MI 48043; Dear Mr. Landers: This is in response to your letter requesting confirmation of a Jul 11, 1983 determination by this agency that your special tow tractor vehicle is exempt from Federal motor vehicle safety standards. You indicate in your letter that you now have three sizes of tow tractors and that your market may expand to include commercial airline use as well as the Department of Defense.; Based on the information you have provided us, we confirm our previou determinations that baggage tow tractors are not subject to the Federal motor vehicle safety standards. The agency has consistently interpreted the definition of motor vehicle as excluding vehicles such as airport runway vehicles that are intended and sold solely for off-road use and are not equipped for highway use. Further, we note that section 571.7(c) of Title 49, Code of Federal Regulations, provides that; >>>No standard applies to a vehicle or item of equipment manufacture for, and sold directly to, the Armed Forces of the United States in conformity with contractual specifications.<<<; Your vehicles might become subject to the Federal motor vehicle safet standards if there is a material change in the facts regarding the intended or actual use, design or sale of your vehicles. Please remember that compliance with all Federal motor vehicle safety standards is the obligation of each manufacturer of motor vehicles or motor vehicle equipment. We appreciate your continuing efforts at classifying correctly your vehicles.; Sincerely, Erika Z. Jones, Chief Counsel |
|
ID: aiam0903OpenMr. Bob Bryan, Sales Coordinator - Direct Sales, Mobile Aerial Towers, Inc., 2314 Bowser Avenue, Fort Wayne, IN 46803; Mr. Bob Bryan Sales Coordinator - Direct Sales Mobile Aerial Towers Inc. 2314 Bowser Avenue Fort Wayne IN 46803; Dear Mr. Bryan: This is in reply to the questions you asked in your letter of Octobe 24, 1972, to Mr. Wells of the Federal Highway Administration concerning compliance with Standard No. 108 of trucks to which mobile aerial towers are mounted.; '1. The aerial tower is considered a load rather than part of th vehicle to be included in determining the overall length. Correct?'; Correct. '2. Are amber *intermediate side marker* lights and/or reflector required on the body?'; If overall length of the vehicle is 30 feet or more, intermediate sid marker lamps and reflectors are required, and they must be located at or near the midpoint between the front and rear side marker lamps and reflectors.; '3. Are amber *side marker* lights and/or reflectors required on th body?'; Front amber side marker lamps and reflectors are required to be mounte as far to the front as practicable on a vehicle. Generally, this is somewhere on the front fender, though in some configurations a manufacturer might determine that a location on the truck body is as far to the front as practicable.; '4. Are amber *clearance* lights and/or reflectors required on th *front* of the body?'; Yes. Front clearance lamps are required to indicate the overall widt of the vehicle and to be mounted 'as close to the top [of the vehicle, exclusive of load] as practicable.'; '5. If a unit is over 30 ft. long, will amber *side marker* lights an reflectors suffice *also* as amber *intermediate side marker lights and reflectors*?'; No, they will not. As the above answers indicate, the locatio requirements are different for front and intermediate side markers.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
|
ID: aiam1611OpenMr. Tatsuo Kato, Staff, Safety, Nissan Motor Company, Ltd., 560 Sylvan Avenue, Englewood Cliffs, New Jersey 07632; Mr. Tatsuo Kato Staff Safety Nissan Motor Company Ltd. 560 Sylvan Avenue Englewood Cliffs New Jersey 07632; Dear Mr. Kato: This is in reply to your letter of September 11, 1974 asking for a interpretation of paragraph S5.3.5 of Standard No. 105-75. You indicate that a prospective Nissan design uses a common indicator lamp to show both loss if fluid pressure and low brake fluid level. You ask if the indicator lamp lens may be labeled 'Brake Failure.'; The answer is no. If separate indicator lamps are used, Standard No 105-75 allows words in addition to 'Brake' to indicate the specific area where a problem may exist, *e.g.* an indicator lamp may be labelled 'Brake Fluid' to indicate a low level of fluid. However, if a lamp indicates more than one type of condition, paragraph S5.3.5 specifies that only a single word, 'Brake', may be used. This alerts a driver in a general way that a problem exists somewhere in the brake system. We think the restriction of S5.3.5 preferable for most circumstances. In the configuration you propose for example, the word 'Failure' would not accurately describe a low level of brake fluid.; We appreciate your continued interest in vehicle safety. Yours truly, Richard B. Dyson, Acting Chief Counsel |
|
ID: aiam2894OpenMr. D.P. Weiher, Office of Corporate Safety, Emissions and Noise Control, AM General Corporation, 32500 Van Born Road, Wayne, Michigan 48184; Mr. D.P. Weiher Office of Corporate Safety Emissions and Noise Control AM General Corporation 32500 Van Born Road Wayne Michigan 48184; Dear Mr. Weiher: This responds to your August 2, 1978, letter asking whether it i permissible to perform the tests of Standard No. 124, *Accelerator Control Systems*, with only part of the vehicle mechanism at the designated temperatures. You state further that there is not sufficient time to find an environmental chamber large enough to accommodate the size vehicle that you are testing.; "The National Highway Traffic Safety Administration (NHTSA) does no issue approvals of manufacturer's plans for compliance with agency standards. Standard No. 124 mandates that a vehicle shall meet the j requirements of the standard at any temperature between -40 degrees F. and 125 degrees F. When the agency tests for compliance with the standard, it fins a chamber sufficiently large to accommodate the entire vehicle and tests according to the standard. Any manufacturer deviation from this accepted test procedure carries with it certain risks that a vehicle may not conform to the requirements."; With respect to the vehicles that you are constructing, you state i your letter that they are being manufactured for use by the army. As such, These vehicles are not required to comply with the agency's safety standards, and the NHTSA would not test these vehicles for compliance.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
|
ID: aiam1122OpenMr. William R. Rodger, Rockwell-Standard Division, Automotive Technical Center, 2445 West Maple Road, Troy, MI 48084; Mr. William R. Rodger Rockwell-Standard Division Automotive Technical Center 2445 West Maple Road Troy MI 48084; Dear Mr. Rodger: By letter of January 31, 1973, Rockwell- Standard requested th National Highway Traffic Safety Administration to postpone the effective date of Motor Vehicle Safety Standard No. 121, *Air Brake Systems*, for twenty-four months with respect to vehicles having front axles with GAWR's of more than 12,000 pounds, single rear axles with GAWR's of more than 23,000 pounds, or tandem rear axles with combined GAWR's of more than 50,000 pounds.; After considering the request, which asks relief from all provisions o the standard, the agency has concluded that an exception of such magnitude is not warranted and therefore denies the request. The agency makes no finding as to whether more limited relief may be appropriate, and does not consider the denial of the January 31 request to preclude the company from submitting petitions for relief from specific aspects of the standard.; Sincerely, James E. Wilson, Associate Administrator, Traffic Safet Programs; |
|
ID: aiam5618OpenMr. Dennis G. Moore President Sierra Products, Inc. 1113 Greenville Road Livermore, CA 94550; Mr. Dennis G. Moore President Sierra Products Inc. 1113 Greenville Road Livermore CA 94550; Dear Mr. Moore: This responds to your letter of July 31, 1995, on th subject of 'optical combination' as that term is used in Motor Vehicle Safety Standard No. 108. You enclosed a copy of a letter sent to you from this Office on March 4, 1977, and refer to a 'Rider' in 'a proposed change around 1990 that had no relevance to this subject, whereas the Rulemakers added the expression, `NOT TO SHARE THE SAME HOUSING.'' You ask how ' u sing the Scientific Argument and discussions I submitted back in 1975, 1976, and 1977, and the Re-Interpretation letter sent me, how can NHTSA support the SAME HOUSING definition they currently support.' You are talking of events of 18 to 20 years ago that are no longer relevant today. The definition that NHTSA supports contains no reference to lamp housings. Standard No. 108 was amended four years ago, in 1991, to clarify that the term 'optical combination' is to be interpreted as defined by SAE Information Report J387 Terminology - Motor Vehicle Lighting NOV87. Under the SAE definition, optical combination results when a lamp 'has two or more separate light sources, or a single light source that operates in different ways (e.g., a two-filament bulb)', and when 'its optically functional lens area is wholly or partially common to two or more lamp functions.' It is immaterial to this definition whether the light sources are in the same or different housings. I enclose a copy of a rulemaking proposal and final rules dealing with this issue that were published on November 6 and 8, 1990, and June 7 and November 7, 1991. If you have further questions, you may refer them to Taylor Vinson of this Office by FAX (202-366-3820). Sincerely, John Womack Acting Chief Counsel Enclosures; |
|
ID: aiam2427OpenMr. Charles G. Atkinson, President, Southern California Recreational Vehicle Products, Inc., 2449 North Naomi Street, Burbank, CA 91504; Mr. Charles G. Atkinson President Southern California Recreational Vehicle Products Inc. 2449 North Naomi Street Burbank CA 91504; Dear Mr. Atkinson: This is in response to your September 15, 1976 letter, concerning th effect of Federal Motor Vehicle Safety Standard No. 301-75, *Fuel System Integrity*, on manufacturers of replacement and auxiliary fuel tanks.; You are correct in your understanding that this standard applies t completed vehicles, rather than fuel tanks or other fuel system components. Therefore, for example, an auxiliary fuel tank that you manufacture is not itself subject to any performance requirements. However, a person who mounts such an auxiliary fuel tank on a new motor vehicle before the vehicle's first purchase in good faith for purposes other than resale is a vehicle alterer under National Highway Traffic Safety Administration regulations. He is required by 49 CFR 567.7 (copy enclosed) to affix a label to the vehicle certifying that, *as altered*, the vehicle conforms to all applicable Federal Motor Vehicle Safety Standards--including Standard No. 301-75.; In addition, the mounting of an auxiliary or replacement fuel tank on motor vehicle after the vehicle's first purchase in good faith for purposes other than resale is affected by Section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act of 1966, as amended (15 U.S.C. 1397 (a)(2)(A)). That section specifies in relevant part that; >>>No manufacturer, distributor, dealer or motor vehicle repai business shall *knowingly render inoperative*, in whole or part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard... . (Emphasis added.); Therefore, such a mounting of an auxiliary or replacement fuel tan must be performed in such a way that the vehicle's compliance with Standard No. 301-75 is not knowingly compromised.; Sincerely, Frank A Berndt, Acting Chief Counsel |
|
ID: aiam5248OpenMr. Terry Karas T.K. Auto Inc. 4116 Notre Dame Chomedey, Laval, Quebec H7w 1T1 Canada; Mr. Terry Karas T.K. Auto Inc. 4116 Notre Dame Chomedey Laval Quebec H7w 1T1 Canada; FAX 514-688-6968 Dear Mr. Karas: This responds to the concern you expressed by telephone to Taylor Vinson of this Office that a phrase in our letter of October 18, 1993, may be misinterpreted by the U.S. Customs Service. The final sentence of the paragraph that begins page 2 of that letter reads: 'If this examination indicates that the vehicle is Canadian, and if it is being imported for commercial purposes, then the vehicle is subject to the registered importer process.' In the context of the letter, we assumed that it was clear that the Canadian vehicle in question was one that did not comply with the U.S. Federal motor vehicle safety standards. You believe that Customs may interpret the word 'Canadian' to mean any vehicle of Canadian manufacture, whether or not complying with the U.S. safety standards. We are pleased to provide the following clarification. With reference to the examination of the Canadian-manufactured vehicle in question, if it indicates that the speedometer does not have mph markings, this will demonstrate that the certification is to Canadian standards. Consequently, the Canadian- manufactured vehicle is one that does not comply, and is not certified as complying, with the U.S. standards, and, if it is being imported for commercial purposes, is subject to entry under bond and the registered importer process. Sincerely, John Womack Acting Chief Counsel; |
|
ID: aiam2077OpenMr. A.J. Burgess, Joseph Lucas North America Inc., Two Northfield Plaza, Troy, Michigan 48084; Mr. A.J. Burgess Joseph Lucas North America Inc. Two Northfield Plaza Troy Michigan 48084; Dear Mr. Burgess: #This is in reply to your letter of May 29, 1975 asking whether two of your processes for labeling brake hose may be considered 'permanent' for purposes of Standard No. 106-74. #As used in our standards and regulations, the requirements for a 'permanent' label generally contemplates a label that will remain legible for the expected life of the product under normal conditions. The National Highway Traffic Safety Administration expects a manufacturer to make a reasonable, good- faith determination in this respect. The two labeling samples that you submitted as examples of your processes appear to be permanent. #We are presently re-examining the requirement for permanent labeling of brake hose, and a Federal Register notice in this area may be issued shortly. #Yours truly, Richard B. Dyson, Assistant 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.