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: aiam1148OpenMr. Charles H. Sturgeon, Traffic Manager, Grove Manufacturing Company, Shady Grove, PA 17256; Mr. Charles H. Sturgeon Traffic Manager Grove Manufacturing Company Shady Grove PA 17256; Dear Mr. Sturgeon: This is in reply to your letter of April 23, 1973, requesting ou confirmation of certain issues discussed by you, and Michael Peskoe and David Fay of NHTSA, in a meeting in Mr. Peskoe's office on April 19, 1973.; It is correct that the NHTSA does not presently employ safet inspectors to inspect vehicles in service. Such inspections are made by inspectors of the Bureau of Motor Carrier Safety in the Federal Highway Administration, and it is true that their primary interest is the enforcement of the Bureau of Motor Carrier Safety regulations (49 CFR Parts 301-398). But if these investigators note violations of NHTSA regulations, the information will be forwarded to NHTSA and appropriate action will be taken.; It is correct that components of a vehicle in service may be added removed, or relocated at the discretion of a vehicle owner without violating NHTSA regulations. However, gross vehicle and axle weight ratings established by the vehicle manufacturer must be based on configurations of the vehicle which the manufacturer expects will be utilized in service. It is also correct that the weight imposed on each axle should not exceed the certified weight rating for each axle, but may be less than the certified weight rating.; Finally, it is correct that gross axle weight ratings may b established with a view towards the weight limitations of States in which the vehicle will be used.; Gross axle and vehicle weight ratings, under NHTSA regulations, ar manufacturers' figures, and may be set at any level as long as the figures are consistent with the limitations specified in the NHTSA certification regulations. However, the weight ratings must also, of course, be consistent with the vehicle's load-carrying capacity.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3175OpenMr. Katsufumi Mitsui, General Manager, Industrial Textile Department, Toray Industries, Inc., 2-2, Nihonbashi-Muromachi, Chuo-ku, Tokyo, Japan; Mr. Katsufumi Mitsui General Manager Industrial Textile Department Toray Industries Inc. 2-2 Nihonbashi-Muromachi Chuo-ku Tokyo Japan; Dear Mr. Mitsui: This responds to a letter we received from Mitsui & Company askin questions concerning the 'resistance to light' test in paragraph S5.1(e) of Safety Standard No. 209, *Seat Belt Assemblies*, as it applies to polyester seat belt webbing. You asked whether it is true that this paragraph will not be enforced for dacron and polyester webbing until an appropriate test method can be incorporated in the standard, and whether such a test method is being developed.; In a July 23, 1976, letter to the Celanese Fibers Marketing Company th agency stated that the Standard No. 209 test procedure for resistance to light was developed to test nylon webbing and that the procedure does not give meaningful results for the new polyester webbings. Therefore, Celanese was informed that the requirement would not be enforced for polyester webbing until a new procedure could be developed. This letter was placed in our public docket for the benefit of all interested parties (in our 'Redbook' interpretations file). The agency does not intend to place an announcement of this interpretation in the *Federal Register*, however, since the standard will soon be amended to incorporate an appropriate test procedure for dacron and polyester webbing.; The new test procedure was developed for the National Highway Traffi Safety Administration by the Narrow Fabrics Institute and the Society of Automotive Engineers Task Force on Webbing. The new procedure would require the use of a plain glass filter instead of the Corex B filter currently required. The agency anticipates rulemaking to incorporate this new procedure sometime early next year, depending on rulemaking priorities.; I am enclosing a copy of our 1976 letter to Celanese for you information.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1518OpenMr. W. G. Milby, Project Engineer, Blue Bird Body Company, P.O. Box 937, Fort Valley, GA, 81035; Mr. W. G. Milby Project Engineer Blue Bird Body Company P.O. Box 937 Fort Valley GA 81035; Dear Mr. Milby: In your letter of May 30, 1974, you ask whether a rear lightin configuration intended for your 1975 vehicles, based upon a proposal in Docket No. 69-19, would meet the current requirement that stop lamps be 'as far apart as possible.'; The photographs you enclose show that the intent of the proposed S8.1 has been met by providing a separation distance between turn signal and stop lamps that is 5 inches or more, and by placing the stop lamp so that its optical axis is inboard of a vertical longitudinal plane passing through the optical axis of the taillamps. Although it is obviously 'practicable' for you to retain the stop lamps in their present location, we consider that the reasons you wish to introduce the change support a determination of practicability under the current requirements, even though the proposal remains under consideration and may not be adopted.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3525OpenMr. Leon W. Steenbock, Project Engineer, FWD Corporation, Clintonville, WI 52929; Mr. Leon W. Steenbock Project Engineer FWD Corporation Clintonville WI 52929; Dear Mr. Steenbock: This responds to your recent letter asking whether Safety Standard No 205, *Glazing Materials*, permits the use of Items 4 and 5 rigid plastics in rear windows on fire trucks. You were confused because the 'ANS Z26' standard permits rigid plastics in these locations, yet Standard 205 is silent on the issue.; The fact that Standard No. 205 does not specifically state that Items and 5 rigid plastics may be used in rear windows in trucks does not mean that such use is not permitted. The 'ANS Z26' standard is incorporated by reference in Standard No. 205 (paragraph S5.1.1). Therefore, glazing materials that conform with 'ANS Z26' may be used in the locations specified in that standard. In addition to the requirements and specified locations in 'ANS Z26,' Standard 205 includes other locations and requirements for additional types of glazing, as well as other locations for the Items of glazing that are specified in 'ANS Z26.'; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3030OpenMr. Donald I. Reed, Director of Engineering, Trailer Manufacturer Association, 401 North Michigan Avenue, Chicago, IL 60611; Mr. Donald I. Reed Director of Engineering Trailer Manufacturer Association 401 North Michigan Avenue Chicago IL 60611; Dear Mr. Reed: This letter corrects an interpretation provided you on June 1, 1979. In our letter, we answered in the negative to your question whether: >>>'whether (sic) it is permissible to combine a clearance lam function in a tail lamp fixture if a second bulb is installed in the tail lamp which, when lit alone, satisfies the photometric requirements of the clearance lamp shown through the tail lamp lens ... and further assuming that all tail lamp photometric requirements are met when the tail lamp bulb alone is lit and when both lamps are lit.'<<<; We commented that such a lamp would appear to create the optica combination prohibited by S4.4.1 when both lamps are lit.; It has been brought to our attention that this conflicts wit interpretations provided on March 4, 1977, to Dennis Moore of Livermore, California, and B.R. Weber of West Bend, Wisconsin, both manufacturers of boat trailer lighting equipment. In our letter to Mr. Weber, for example, we interpreted 'optically combined' to mean a situation in which 'the same light source (i.e., bulb) and the same lens area fulfill two or more functions (i.e., tail lamp, and stop lamp, clearance lamp and turn signal lamp)'. The phrase is not intended to prohibit the installation of two separate bulbs in a single housing and covered by a common lens.; Upon review, we believe that the interpretation of March 4, 1977, i the correct one, and that the conflicting interpretation of June 1, 1979, should be with error. We are sorry for any confusion this may have caused your members.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3460OpenMr. Charles Schamblin, Flag-It Signaling Device Co., P.O. Box 1709, Bakersfield, CA 93302; Mr. Charles Schamblin Flag-It Signaling Device Co. P.O. Box 1709 Bakersfield CA 93302; Dear Mr. Schamblin: The National Transportation Safety Board has forwarded for reply you letter of June 10, 1981, asking whether the 'Flag-It Automobile Signaling Device' would be legal to use according to your new regulations . . . .'; Requirements for equipment use are not established by the Federa government but by the individual State in which a vehicle is registered.; Our agency within the Department of Transportation establishes th Federal motor vehicle safety standards which apply to vehicle and equipment manufacturers. Your device consists of reflectors which hang beneath the front and rear bumper. They are not covered by our standard on reflectors (Standard No. 108 *Lamps, Reflective Devices and Associated Equipment*) nor would their installation appear to impair the effectiveness of lighting equipment required by Standard No. 108, which could raise a question as to their legality.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2621OpenMr. Jack Gromer, Vice President - Technical Operations, Timpte, Inc., 5990 N. Washington Street, Denver, CO 80216; Mr. Jack Gromer Vice President - Technical Operations Timpte Inc. 5990 N. Washington Street Denver CO 80216; Dear Mr. Gromer: This responds to your May 6, 1977, letter asking whether your tir information label complies with the requirements of Standard No. 120, *Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars, and Part 567, *Certification*. Further, you request that the National Highway Traffic Safety Administration (NHTSA) expedite treatment of Docket No. 73-31, Notice 1, which, if implemented would simplify the certification and information labels.; Concerning Docket 73- 31, the NHTSA published on June 20, 1977, notice (42 FR 31161) implementing Notice 1 which proposed the use of the designation 'all axles' rather than listing each axle individually on the certification label. The implementation of this regulation should resolve many of your problems.; Regarding the sample information label you submitted with your letter the NHTSA does not give advance approvals of compliance with Federal safety regulations or standards. We will, however, give an informal opinion of whether your label appears to comply with the requirements. The label you submitted does not appear to comply with the requirements of Part 567 or Standard No. 120. I have enclosed copies of both of these regulations for your information.; Your certification label should use the designation 'all axles' no 'each axle.' The tire and rim information should follow that designation stated in the form presented in the examples in Standard No. 120 and Part 567.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3933OpenMr. Hayley Alexander, Marketing Consultant, The LondonCoach Co., Inc., P.O. Box 1183, Mt. Clemens, MI 48043; Mr. Hayley Alexander Marketing Consultant The LondonCoach Co. Inc. P.O. Box 1183 Mt. Clemens MI 48043; Dear Mr. Alexander: This is in reply to your letter of March 25, 1985, asking for ou comments on your planned London Taxi marketing program.; Under the program, products of Carbodies Ltd. of Coventry, England would be imported 'devoid of an engine, transmission, and finished interior.' LondonCoach would then install 'an American engine, transmission and driveshaft, interior seats, coverings and details, and various exterior cosmetic trim items.' However, a 'representative' vehicle with the modifications mentioned above will have undergone all testing necessitated by the standards, at the Motor Industry Research Association in England. Vehicles would be certified by Carbodies as meeting the standards prior to importation, and LondonCoach Co., Inc., in the role of alterer, would attach the label attesting to continued compliance required by 49 CFR Section 567.7 upon completion of the modifications.; Under the National Traffic and Motor Vehicle Safety Act, certificatio of compliance of a motor vehicle can only be provided by the manufacturer or importer of a completed motor vehicle. Certification of compliance with at least four Federal motor vehicle safety standards is directly dependent upon the manner in which the Carbodies vehicles are completed by LondonCoach: Standard No. 124, *Accelerator Control Systems*, Standard No. 207, *Seating Systems*, Standard No. 301, *Fuel System Integrity*, and Standard No. 302, *Flammability of Interior Materials*. Therefore, LondonCoach is the only party who can certify compliance of the completed vehicle with Federal motor vehicle safety standards. As the manufacturer, LondonCoach is also responsible for assigning and affixing the vehicle identification number (VIN) to each vehicle, according to the requirements of Standard No. 115, *Vehicle Identification Number--Basic Requirements*, and 49 CFR Part 565, *Vehicle Identification Number--Content Requirements*.; The Carbodies products are an assemblage of items of motor vehicl equipment and should be labeled as equipment items for importation into the United States. Carbodies should certify that each item of motor vehicle equipment that is covered by a Federal motor vehicle safety standard complies with such standard. Those items are brake hoses, new pneumatic tires, brake fluid, surface glazing, seat belt assemblies, and lamps, reflective devices, and associated equipment. This certification should free LondonCoach, as the importer, from the obligation under 19 CFR 12.80 to post a compliance bond upon entry into the United States.; Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam2271OpenMr. Roger E. Stange, President, Norton Triumph Corporation, P.O. Box 275, Duarte, California 91010; Mr. Roger E. Stange President Norton Triumph Corporation P.O. Box 275 Duarte California 91010; Dear Mr. Stange: This is in reply to your letter of April 1, 1976, which requests a interpretation of Motor Vehicle Safety Standard No. 123 as it applies to a motor-driven cycle that your company intends to import.; "The speedometer on this machine displays both minor numerals and mino graduations at 5 mph intervals. Paragraph S5.2.3 and Column 3 of Table 3 of Standard No. 123 require that, if a motorcycle is equipped with a speedometer, 'Major graduations and numerals shall appear at 10 mph intervals, minor graduations at 5 mph intervals.' S5.2.3 also states that the abbreviations used in Column 2 and 3 are j minimum requirements and 'appropriate word may be spelled in full.' It is your interpretation that 'if the abbreviations used in Column 3 are minimum requirements ... the speedometer in question meets the minimum requirements and is therefore in conformity with the standard.'"; The 'abbreviations' only refer to words and not to numerals o graduations. However, since there is no specific prohibition against providing minor numerals at the minor graduations, we have concluded that Standard No. 123 allows a motorcycle manufacturer to furnish a speedometer with them if he so chooses.; Yours truly, Stephen P. wood, Assistant Chief Counsel |
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ID: aiam3899OpenMr. Ernest Farmer, Director, Pupil Transportation, Tennessee State Department of Education, Office of Commissioner, Cordell Hull Building, Nashville, TN 37219-5335; Mr. Ernest Farmer Director Pupil Transportation Tennessee State Department of Education Office of Commissioner Cordell Hull Building Nashville TN 37219-5335; Dear Mr. Farmer: This responds to your letter to me regarding our motor vehicle safet standards for school buses. You asked several questions about Standard No. 222, *School Bus Passenger Seating and Crash Protection*, and Standard No. 301, *Fuel System Integrity*. In a telephone conversation you had on February 8, 1985, with Ms. Hom of my staff, you also asked about the safety standards that apply to vans carrying 10 or less persons that are used to transport school children.; To begin, I would like to explain that the motor vehicle safet standards issued by our agency apply to the manufacture and sale of new motor vehicles. As you know, in 1974, Congress expressly directed us to issue standards on specific aspects on school bus safety. The standards we issued became effective April 1, 1977, and apply to each school bus manufactured on or after that date. A manufacturer or dealer who sells a new bus to a school must sell a bus that complies with the motor vehicle safety standards applicable to school buses.; Under our regulations, a 'bus' is defined as a motor vehicle designe for carrying 11 or more persons. 'School bus' is defined as a bus that is sold for purposes that include carrying students to and from school or related events (excluding buses sold as common carriers in urban transportation). A van type vehicle, constructed on a truck chassis, carrying 10 persons or less is classified as a multipurpose passenger vehicle (MPV). New MPV's sold to schools need not meet the school bus safety standards, since these vehicles are not buses. However, there are many motor vehicle safety standards applicable to MPV's. New MPV's must be certified by their manufacturers as complying with these safety standards. I have enclosed a list of the motor vehicle safety standards applicable to MPV's, as you requested.; The first question in your letter asked whether we require 'Type A vehicles which carry 15 to 22 passengers to comply with the provisions of Standards Nos. 222 and 301. Over the telephone, you explained that these vehicles are school buses with gross vehicle weight ratings (GVWR) of 10,000 pounds or less.; The answer to this question is yes. Standard No. 222 applies to al school buses. However, the requirements of the standard vary depending on the GVWR of the bus. Standard No. 301 applies to all school buses that use fuel with a boiling point above 32 degrees F. A new school bus must be certified as complying with the applicable requirements of these safety standards.; The first part to your second question asked, 'Does NHTSA consider 14- inch crash barrier installed in front of standard 39-inch bench seats on the right side of the aisle in these vehicles to be in compliance with FMVSS 222?'; The answer to this question is that there is no violation of Standar No. 222's restraining barrier requirements. This is because the restraining barrier requirements do not apply to school buses of 10,000 pounds or less GVWR. Paragraph S5(b) of the standard lists the requirements that apply to these smaller school buses, and the restraining barrier requirements found in paragraph S5.2 are not listed in S5(b). If a manufacturer voluntarily chooses to install a restraining barrier in these buses, there is no violation of Standard No. 222 if the barrier is not as wide as the designated seating positions behind it.; The second part of this question asked, 'Would seat belts on the fron row of seats void the crash barrier requirement in this statement for Type A vehicles? (We are aware that NHTSA requires seat belts on all Type A vehicles)'; The answer to this question is similar to that given above. Restrainin barriers on school buses with GVWR's of 10,000 pounds or less are not required by Standard No. 222. Since these smaller school buses are equipped with seat belts, the standard does not regulate seat spacing in these vehicles.; The third part of this question asked, 'Would the location of the ga tank between frame members also void the requirement in FMVSS 301 for a protection barrier?'; The answer is that Standard No. 301 sets performance requirements tha each school bus must meet, it does not require specific designs, such as a protective barrier. A manufacturer can position its gas tank at any location as long as it can meet the performance requirements of the standard at that location.; Your third question asked, 'Does NHTSA require the installation of metal shield between the exhaust system and the gas tank when such locations are 12 inches or less from each other? (Note: We have some Type A vehicles with variations of 6 to 8 inches that supposedly have NHTSA approval.)'; Neither Standard No. 301 nor any of the agency's other standards se any requirements concerning the installation of metal shields between the exhaust system and the gas tank.; If you have further questions, please do not hesitate to contact us. 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.