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: aiam5092OpenMr. Mike Love Manager, Compliance Porsche Cars North America, Inc. P. O. Box 30911 Reno, Nevada 89520-3911; Mr. Mike Love Manager Compliance Porsche Cars North America Inc. P. O. Box 30911 Reno Nevada 89520-3911; "Dear Mr. Love: This responds to your request that NHTSA determine tha a proposed modification to a previously approved antitheft device on the Porsche 911 car line constitutes a de minimis change to the device. The change is proposed to be made on only one model in the 911 line and to be effective beginning with the 1994 model year (MY). As explained below, the agency concludes that the proposed change to the antitheft device is not a de minimis change. As you are aware, in a Federal Register notice of June 2, 1989 (54 FR 23727), NHTSA determined that the antitheft device, to be placed as standard equipment on the MY 1990 Porsche 911 car line, was likely to be as effective as parts marking. Subsequently, by letter dated May 31, 1990, the agency concluded that proposed changes to the antitheft device in the MY 1991 Porsche 911 car line were de minimis changes. The primary change for the 1991 model year was that the interior light control units were to be integrated with the alarm control unit and central locking system. The latter two components were already integrated. For the following reasons, NHTSA concludes that the proposed change to the antitheft device for the 1994 model year is not de minimis. In reaching this conclusion, we looked primarily at the anti-theft system on which the exemption was originally based. Under the original system, locking one door would automatically lock all doors, as well as arm the alarm system. Under the proposed change, locking one door with the key would no longer automatically lock all doors, but would still arm the alarm system. This is not an insignificant change like the substitution of new components for old components, each serving the same function. Nor does the change involve adding a feature making an exempted antitheft device even more effective. The change in question lessens the likelihood that all doors of a car will be locked, thus easing a thief's access to the passenger compartment. A thief may easily open the unlocked door, providing an opportunity to attempt to shut off the alarm system (since both the alarm control unit and the power lines from the battery to the alarm system are inside the vehicle) and to circumvent the engine disabling system. If the thief successfully overcomes these systems, theft of the entire vehicle or its parts is facilitated. Once inside the vehicle, a thief may open the hood by a release in the vehicle interior, thereby gaining access to the storage space under the hood. Since the battery for the Porsche 911 is also located in the front hood compartment of the vehicle, access to the battery also makes it easier for a thief to attempt to shut off the alarm system and engine disabling system, again facilitating theft of the entire vehicle or its parts. Because the same aspects of performance (i.e., the central door locking system that automatically locked all doors, making access to the vehicle interior and hood release more difficult), are not provided in the proposed device, resulting in the possibility of the vehicle's increased vulnerability to being stolen in whole, or to have its parts stolen, this agency concludes that Porsche's proposed modification to the antitheft device in one model in the MY 1994 911 car line is not a de minimis change. If Porsche wishes to place its proposed antitheft device on the 911 car line, it must formally file a petition with NHTSA pursuant to 49 CFR 543.9(c)(2). Please note that the petition for a modification must provide the same information for the modified device as is required under 543.6 for a new device. This includes the statement in 543.6(a)(1) that the antitheft device will be installed as standard equipment on all cars in the line for which an exemption is sought. Since the modification planned by Porsche would result in one model within the car line lacking a feature found on the anti-theft systems of other models, the agency would determine in the following manner whether the car line continued to merit exemption. It would regard the system of the one model as the system of the car line as a whole and assess whether that system would be as effective in preventing theft as parts marking. The additional feature on the other models within the car line, i.e., the central locking system, would be regarded as an addition to the standard equipment system and would not have any bearing upon the exemptability of the car line. NHTSA notes that this same approach would not be taken if the system to be installed on a single model within a car line could not be regarded as a stripped down version of the system on the other models. In that case, there would be no standard equipment version of the system and the car line would not be eligible for an exemption. If you have any questions, please contact Ms. Barbara A. Gray, Chief, Motor Vehicle Theft Division, Office of Market Incentives, Office of Rulemaking, NHTSA, at this address or by telephone at (202) 366-1740. Sincerely, Barry Felrice Associate Administrator for Rulemaking"; |
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ID: aiam2757OpenMr. R. C. Evans, Vice President, O Sullivan Corporation, P.O. Box 603, Winchester, VA 22601; Mr. R. C. Evans Vice President O Sullivan Corporation P.O. Box 603 Winchester VA 22601; Dear Mr. Evans: This is in reply to your letter of February 3, 1978, to Mr. Guy Hunte of my staff, requesting assignment of a DOT' code number for purposes of Federal Motor Vehicle Safety Standard (FMVSS) No. 205, *Glazing Materials*. You state that you supply vinyl plastic sheeting to your customer who, in turn, laminates and polishes this sheeting for use as glazing in the rear window opening of convertibles.; Under paragraph S6 of FMVSS No. 205 (a copy was previously mailed t you), the assignment of a code number is restricted to prime glazing material manufacturers. Prime glazing material manufacturers are those who either fabricate, laminate, or temper the glazing material. Since you merely supply the material to your customer who then laminates and polishes it for use as glazing, you are not considered the prime manufacturer and assignment of a code number to you is not appropriate. Your customer is the prime manufacturer in this case and it is his responsibility to certify that his glazing meets the requirements by the means specified in FMVSS No. 205.; If I can be of further help, do not hesitate to contact me. Sincerely, E. T. Driver, Acting Associate Administrator for Rulemaking |
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ID: aiam3845OpenMr. Donald M. Schwentker, Schnader, Harrison, Segal & Lewis, Suite 1100, 900 Seventeenth Street, N.W., Washington, D.C. 20006; Mr. Donald M. Schwentker Schnader Harrison Segal & Lewis Suite 1100 900 Seventeenth Street N.W. Washington D.C. 20006; Dear Mr. Schwentker: This responds to your letter of May 9, 1984, concerning the applicatio of Standard No. 208, *Occupant Crash Protection*, and Standard No. 209, *Seat Belt Assemblies*, to an emergency locking retractor designed by one of your clients. The following discussion addresses the application of those standards to the retractor.; You explained that the purpose of the new emergency locking retracto (ELR) is to facilitate the securing of a child restraint in a vehicle. The ELR would only be installed in forward-facing passenger seating positions. The new ELR is designed so if the belt is pulled all the way out of the retractor, the ELR will convert into an automatic locking retractor (ALR). Once all but 1393-1493 mm of the belt retracts, the retractor will revert automatically to the ELR mode.; You further explained that the continuous loop lap and upper torso bel used with this retractor is 380 mm longer than the belt system provided for the driver's seating position. You explained that the extra 380 mm of belt webbing is meant 'to permit normal occupant movement without inadvertent actuation of the ALR mode while still rendering it convenient for manual extension when the ALR mode is desired for child restraint use.'; You specifically asked whether the retractor designed by your clien would be considered an ELR for the purposes of S7.1.1 of Standard No. 208. In addition, you asked about the retractor durability tests of S5.2(k) of Standard No. 209. As a part of that test, a retractor is subjected to '45,000 additional cycles of webbing withdrawal and retraction between 50 and 100 percent extension.' You asked whether, for the purposes of the section 5.2(k) test, the length of the driver's belt, which is 380 mm shorter than the passenger's belt, could be used to determine what constitutes 100 percent extension of the belt. You alternatively asked whether the test could be stopped before complete extension of the passenger belt.; As we understand your client's seat belt assembly, the amount o webbing in the driver's side assembly complies to the adjustment requirements of section 4.1(kg) of Standard No. 209. The 380 mm's of extra webbing that is included in the passenger's seat belt assembly has been voluntarily added as a precaution to reduce the possibility of an occupant inadvertently actuating the ALR mode of the retractor. Based on the information you have provided, it appears that in normal operation by occupants covered by the adjustment requirements of Standard No. 209 the retractor functions exclusively as an ELR and thus can be used to meet the requirements of S7.1.1 of Standard No. 208. The agency views the 380 mm's of extra webbing as a voluntary addition not required by the standard. Therefore, for the purpose of section 5.2(k) of Standard No. 209, the agency will use the length of the driver's belt to determine what constitutes full extension of the webbing.; Sincerely, Frank Berndt, Chief Counsel. |
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ID: aiam1878OpenMr. John S. Knaur, Jr., Brougham Industries, P.O. Box 768, 101 Bolivar Street, Sanger, TX 76266; Mr. John S. Knaur Jr. Brougham Industries P.O. Box 768 101 Bolivar Street Sanger TX 76266; Dear Mr. Knaur: This responds to your March 17, 1975, request for an explanation of th seat belt assembly installation requirements of Standard No. 208, *Occupant crash protection*, as they apply to motor homes with a gross vehicle weight rating (GVWR) of more than 10,000 pounds, and those with a GVWR of 10,000 pounds or less.; The standard requires that motor homes with a GVWR of more than 10,00 pounds be equipped with 'passive' crash protection of a certain level (S4.3.1) or a Type 1 or Type 2 seat belt assembly at each designated seating position (S4.3.2).; Motor homes with a GVWR of 10,000 pounds or less must be equipped wit 'passive' crash protection of a certain level (S4.2.1.1) or a Type 2 seat belt assembly at each outboard designated seating position that includes the windshield header within the head impact area, and a Type 1 or Type 2 seat belt assembly at each other designated seating position(S4.2.1.2).; At the front outboard designated seating position, you state that th incomplete vehicle manufacturer provides Type 1 seat belts. Unless the documentation, provided under Part 568 of our regulations (49 CFR Part 568), states that modification of the Type 1 seat belts is required to meet Standard No. 208, it appears that the vehicle windshield header is not within the head impact area and that Type 1 seat belts meet the requirement.; You point out that some manufacturers may not provide as man designated seating positions as there are sleeping accommodations in the vehicle. We evaluated the proportion of this problem recently because of the possibility that occupants were not being provided with enough Type 1 seat belts. An informal but comprehensive survey at a recent trade show indicated that the problem is extremely limited. If you have information that this practice is becoming more common, please provide this office with more specific identification of manufacturer and model line.; We do appreciate your efforts to provide your purchasers with a hig level of crash protection.; Sincerely, James C. Schultz, Chief Counsel |
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ID: aiam2242OpenMr. Gerald Werner, President, Werner Incorporated, P.O. Box 310, 10861 Straits Hwy., Cheboygan, MI 49721; Mr. Gerald Werner President Werner Incorporated P.O. Box 310 10861 Straits Hwy. Cheboygan MI 49721; Dear Mr. Werner: This is in response to your letter of November 20, 1975, concernin certification of your company's roof vents as being in compliance with Federal Motor Vehicle Safety Standard No. 205, *Glazing Materials*.; In our correspondence to you of August 25, 1975, we stated that roo vent covers of the type your company manufactures are subject to the requirements of Standard No. 205. However, we also stated that the National Highway Traffic Safety Administration (NHTSA) concurred in the view that roof vent covers manufactured by the injection molding process were not susceptible to testing under the procedures found in USAS Z26.1. Further, we informed you that the NHTSA intended to issue proposed rulemaking that would establish a surrogate testing procedure for these roof vent covers, and that until this was done the NHTSA would not take action against manufacturers who did not certify that their injection molded covers met the requirements of Standard No. 205.; Upon further consideration and review, however, the NHTSA ha determined that it must retract its earlier concurrence in the view that roof vent covers manufactured by the injection molding process are not susceptible to testing under the procedures specified in USAS Z26.1.; The earlier concern that the USAS Z26.1 test procedures wer inappropriate for testing the covers was based upon the fact that the USAS tests call for 'substantially flat specimens'. Manufacturers of the roof vents contended that covers manufactured by the injection molding process were not 'substantially flat' in their finished condition or at any time during their manufacture, and hence could not be tested for compliance with USAS Z26.1 requirements.; The NHTSA has since concluded that manufacturers can test their roo vent product under the procedures specified in USAS Z26.1, and thereby certify compliance with Standard No. 205. The USAS tests do not require the test specimens to be cut from the actual product--in this case the roof vent covers. Therefore, although the vent covers themselves are not 'substantially flat,' it is possible to mold flat specimens of the same material for purposes of the USAS tests. Consequently, it is not necessary that the NHTSA issue new surrogate testing procedures.; Since this is a reversal of our previous position, the NHTSA will no consider this interpretation to take effect with respect to glazing manufactured before September 1, 1976.; Please contact us if we can be of any further assistance. Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam5587OpenGeorge E. Walton International Manufacturer's Consultants, Inc. 7618 Winterberry Place Bethesda, MD 20817; George E. Walton International Manufacturer's Consultants Inc. 7618 Winterberry Place Bethesda MD 20817; Dear Mr. Walton: This responds to your July 13, 1995 letter requestin an interpretation regarding the requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 205, 'Glazing Materials.' You stated in your letter that your client wants to know if Standard No. 205 permits the use of laminated AS-1 glass in motorcycle windshields. The answer to your question is yes. ANSI Z26.1-1977, which has been incorporated by reference into Standard No. 205, explicitly refers to item 1 glazing (defined as including laminated glass) as 'Safety Glazing Material for Use Anywhere in Motor Vehicle.' Motorcycles are motor vehicles. Therefore, item 1 glazing is permitted in that application. I hope this information is helpful. Please feel free to contact Paul Atelsek of my staff at this address or by telephone at (202) 366-2992 if you have any further questions or need additional information. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam0785OpenMr. Philip Ralston, Aero Precision Inc., 3608 Stone Avenue, Colorado Springs, CO 80907; Mr. Philip Ralston Aero Precision Inc. 3608 Stone Avenue Colorado Springs CO 80907; Dear Mr. Ralston: This is in reply to your letter of July 5, 1972, concerning th applicability of Standard No. 215, Exterior Protection, to the bumpers you manufacture for pickup trucks.; Standard No. 215 does not apply to vehicles other than passenger cars so that pickup trucks equipped with your bumper would not have to conform.; We do not have the facilities to conduct product evaluation tests o the type you have in mind. We are enclosing a copy of the standard, however, for your review. The test procedures are set out in sections S6 and S7.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1897OpenHonorable Dante B. Fascell, House of Representatives, Washington, DC 20515; Honorable Dante B. Fascell House of Representatives Washington DC 20515; Dear Mr. Fascell: This is in response to your letter of March 31, 1975, forwardin correspondence from Mr. Gurth G. West commenting on a proposed amendment to the Federal bumper standard by urging that recyclability of bumpers be assured.; Although promulgation of rules that have a direct positive impact o the environmental and energy situation is not within the National Highway Traffic Safety Administration's (NHTSA) jurisdiction, the agency gives serious consideration to the effect any of its standards will have on these important areas of concern.; The NHTSA's most recent proposal (March 12, 1975, 40 F.R. 11598, Docke No. 74-11, Notice 7, Docket No. 73-19, Notice 6) ensures that a wide variety of materials, including metals, could continue to be used in bumper systems.; We greatly appreciate your interest and that of Mr. West in thi matter. You can be sure that his comments will be given every consideration.; Sincerely, James C. Schultz, Chief Counsel |
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ID: aiam2612OpenMr. Matt Kolb, Suite 937 Spitzer Building, Toledo, OH 43604; Mr. Matt Kolb Suite 937 Spitzer Building Toledo OH 43604; Dear Mr. Kolb: This responds to your April 18, 1977, letter asking whether ou regulations pertaining to truck-camper loading apply to trucks designed to haul fifth-wheel trailers.; Truck manufacturers are required to supply information pertaining t the cargo weight rating and longitudinal limits for the center of gravity of those vehicles capable of accommodating slide-in campers (Code of Federal Regulations, Volume 49, Part 575.103, *Truck-camper loading*). Slide-in camper is defined as 'a camper having a roof, floor, and sides, designed to be mounted on and removable from the cargo area of a truck by the user.' The purpose of this information requirement is to lessen the possibility of vehicle overloading. Since fifth-wheel trailers do not fall within the definition of slide-in camper, the regulations pertaining to truck-camper loading do not apply to vehicles designed to haul these trailers.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3900OpenMr. 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 a 1 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 standard for Type A vehicles? (We are aware that NHTSA requires seat belts on all Type A vehicles)'(sic); 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 protective 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.