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: aiam1892OpenHonorable Edwin B. Forsythe, House of Representatives, Washington, DC 20515; Honorable Edwin B. Forsythe House of Representatives Washington DC 20515; Dear Mr. Forsythe: This is in response to your letter of March 31, 1975, requestin information concerning correspondence from one of your constituents, Mr. Anthony N. D'Elia, commenting on a proposed amendment to the Federal Bumper Standard.; On January 2, 1975, the National Highway Traffic Safety Administratio (NHTSA) issued a Federal Register Notice (copy enclosed) proposing to reduce the current 5 mph bumper impact requirements to 2.5 mph until the 1979 model year. The impact requirements would have been increased to 4 mph for 1979 and later model year cars.; The proposal was based primarily on the results of two agency sponsored studies which indicated that the cost and weight of many current production bumpers, in light of inflation and fuel shortages, made the bumpers no longer cost beneficial. Information presented at public hearings on the bumper notice and comments submitted to the docket in response to the proposal have brought to light additional data. The NHTSA has carefully examined all of this evidence and reviewed its studies in light of the new information. As a result, the agency has concluded that the 5 mph protection level should not be reduced. This decision is contained in a Federal Register notice that was published March 12, 1975, which is enclosed (Docket No. 74-11, Notice 7, Docket No. 73-19, Notice 6).; Another public hearing was held on April 4, 1975, to allow ora presentation of views on the March 12 notice. The agency is currently examining the information gathered at that proceeding in addition to the written comments that have been submitted. The next step in our rulemaking process will be based on all of the data available.; Your interest and that of Mr. D'Elia is greatly appreciated. Sincerely, James C. Schultz, Chief Counsel |
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ID: aiam0780OpenMr. J. C. Eckhold,Automotive Safety Director,Ford Motor Company,The American Road,Dearborn, Michigan 48121; Mr. J. C. Eckhold Automotive Safety Director Ford Motor Company The American Road Dearborn Michigan 48121; Dear Mr. Eckhold:#This is in reply to your letter of June 20, 1972, t Mr. Toms concerning general reference material in support of the proposals contained in Docket No. 70-27.*Hydrauli- c Brake Systems.* You ask that the NHTSA place in the file 'The supporting data upon which the test sequence is based as well as the data used to determine the performance values based on the sequence.'#The proposed test sequence is based primarily upon the test sequence of standard No. 105, which is that if SAE Recommended Practice J937 incorporated by reference. Parking brake, lightly loaded vehicle, inoperative brake power assist unit, and partial failure tests not included in J937, were placed in the sequence in order that appeared, in the judgment of agency personnel, most likely to provide realistic and undistorted results. The sequence, of course, is subject to revision on the same basis in the forthcoming final rule. General reference material in the Docket includes data from braking tests of eighteen 1970 automobiles, NBS Technical Note 557,'The Brake Pedal Forces Capability of Adult Females,' and SAE 7200032,'Eval- uation of the use of Automotive Braking Systems During a 7300 Mile Cross-County Trip.'#Sincerely,Lawrence R. Schneider,Chief Counsel; |
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ID: aiam5078OpenMr. Wolfgang W. Klamp 8105 Chehalis Road Blaine, Washington 98230; Mr. Wolfgang W. Klamp 8105 Chehalis Road Blaine Washington 98230; "Dear Mr. Klamp: This responds to your letter of October 28, 1992, wit respect to problems encountered by your wife in her use of a 1992 Canadian Ford Tempo passenger car. Your letter indicates that your wife works in Canada, and uses the Ford, a company car owned by her employer, to travel to and from her home in the United States. Because the vehicle is not certified as meeting the U.S. Federal motor vehicle safety standards, she has been informed by U.S. Customs officials at the border that it may not be admitted in the future without going through the formal entry process for conversion to the U.S. standards. You have asked for our consideration of this matter. The National Traffic and Motor Vehicle Safety Act prohibits the importation into the United States of motor vehicles that do not conform, and that are not certified by their manufacturers to conform, to all applicable U.S. Federal motor vehicle safety standards. As a legal matter, each time the Ford crosses the border from British Columbia to Washington, it is being imported into this country. It has been the policy of this agency for many years to regard Canadian and Mexican-registered vehicles engaged in daily cross-border traffic as subject to the importation prohibitions of the Act, and to require their compliance with the U.S. Federal motor vehicle safety standards. This is the reason why your wife is encountering difficulties at the border. We have several suggestions. If the Ford is equipped with automatic occupant protection such as an air bag or automatic belts, it may, in fact, comply with all the U.S. standards. If this is the case, then Ford of Canada may be willing to provide your wife with a letter certifying its compliance to the U.S. standards which she could present at the border. Customs should honor such a letter, and allow the vehicle to proceed with no further delay. If this is not the case, perhaps her employer could provide her with a Canadian-manufactured car that does meet, and is certified as meeting, the U.S. standards. Otherwise, your wife may have to use a U.S.-registered and certified vehicle and seek reimbursement for travel expenses from her Canadian employer. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam2247OpenMr. George A. Hunt, Engineering Manager, Motor Coach Industries, Inc., Pembina, ND 58271; Mr. George A. Hunt Engineering Manager Motor Coach Industries Inc. Pembina ND 58271; Dear Mr. Hunt: This responds to Motor Coach Industries' February 20, 1976, lette asking whether Standard No. 121, *Air Brake Systems*, requires the installation of parking brakes on all non-steerable axles of a bus, including a lightly-loaded axle, in satisfaction of the emergency braking provisions of S5.7.1. Once parking brakes are applied on the non-driving, lightly-loaded axle on some Motor Coach Industries (MCI) buses in cold, wet weather, the linings can freeze to the drums and 'lock' the wheels so that they will not turn even after the parking brake is released. You suggest that parking brakes are inappropriate on a lightly-loaded axle, citing an interpretation of the standard that stated parking brakes are not required on an air-lift axle which lifts off the ground when the vehicle is parked.; MCI raised the same question of parking brake requirements fo lightly-loaded axles in an April 17, 1972, letter requesting interpretation of the provision of S5.7.1 that requires automatic application of parking brakes. At the time, the NHTSA had just issued S5.7.1, expanding the methods for meeting performance levels for emergency braking performance. The question of whether parking brakes should be required on all axles under S5.7.1 was left open pending formal rulemaking.; What was not raised in MCI's April 1972 letter was whether both method for meeting S5.7.1 performance levels necessitate parking brakes on all non-steerable axles. Section S5.7.1.2 permits reliance on retardation force capabilities of each non-steerable axle or, in the alternative, reliance on vehicle stopping capability using the vehicle's available parking brakes. In the second case, the NHTSA does not interpret S5.7.1 to require installation of parking brakes on an axle if it is not necessary to meet the stopping performance of S5.7.2.3 specified under S5.7.1.2. To the degree the language of S5.7.1 does not specifically address this method of satisfying the requirement, we regret that the agency's July 1972 response was not more clear.; An interpretative amendment of S5.7.1 would be appropriate in view o the difficulties that its misinterpretation has caused. However, in view of the short time remaining before the automatic application option will no longer be available, the NHTSA does not expect to undertake rulemaking to formalize this interpretation.; Yours truly, Frank Berndt, Acting Chief Counsel |
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ID: aiam5582OpenMr. Michael J. Wirsch Manager Electric Transportation Department Sacramento Municipal Utility District P.O. Box 15830 Sacramento, CA 95852-1830; Mr. Michael J. Wirsch Manager Electric Transportation Department Sacramento Municipal Utility District P.O. Box 15830 Sacramento CA 95852-1830; "Dear Mr. Wirsch: This is in reply to your letter of June 16, 1995 relating to the disposition of 16 City-El electric vehicles ('EVs') which were imported into the United States in 1992 for purposes of demonstration and testing. The EVs do not meet the Federal motor vehicle safety standards. The EVs were imported pursuant to the declaration that, at the end of the test period, they would be exported or brought into compliance with the Federal motor vehicle safety standards not later than November 1995. You suggest that there may be a third alternative, which you would prefer: 'transferring ownership' to McClellan Air Force Base for use on base property and not on the public roads. McClellan apparently has been testing another group of 25 EVs. Although a literal interpretation of our regulations does not permit this transaction without exportation and reimportation of the EVs, we have determined that the transaction you propose is in the public interest, and may be accomplished, subject to the terms of this letter. In brief, the regulation under which the EVs were imported does not allow transfer of ownership or possession, and provides that such vehicles must be exported or brought into compliance with all applicable Federal motor vehicle safety standards at the end of the period for which admission has been authorized. The regulations would permit the EVs to be exported to Mexico or Canada, transferred to McClellan, and reimported into the United States by McClellan under the same terms and conditions as the original importation (your letter indicates that McClellan may also be engaged in an evaluation of electric vehicles for use on military bases). We assume that this course of action would be acceptable to you and to McClellan. Under that assumption, we have tentatively concluded that it would be in the public interest to forego the formalities and to allow a direct transfer of the EVs to McClellan without requiring them to be exported. However, in order to allow us to reach a final conclusion, we want you to obtain from McClellan and to provide us with a written statement similar to what McClellan would have provided had it imported the vehicles itself. Understanding from you that the EVs will not be operated on the public roads, McClellan should also provide this assurance. We also need a statement as to McClellan's eventual intended disposition of the EVs, which should include an assurance that none of the EVs will be sold to individuals for on-road use. This is especially important in view of the fact that McClellan appears to be one of the military bases that has been selected for closure. Our eventual agreement to the transaction you propose will not relieve you of your obligation to fulfill the requirements of the U.S. Customs Service regarding the original importation of the EVs. If you have any further questions, you may refer them to Taylor Vinson of this Office (202-366-5263). Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam5428OpenMr. Keith E. Smith Piper & Marbury 2 Penn Center Plaza, Suite 1500 Philadelphia, PA 19102-1715; Mr. Keith E. Smith Piper & Marbury 2 Penn Center Plaza Suite 1500 Philadelphia PA 19102-1715; Dear Mr. Smith: This responds to your letter asking whether th National Highway Traffic Safety Administration (NHTSA) considers automotive and motorcycle braking systems to be 'safety devices.' As explained below, the agency considers such systems to be items of motor vehicle equipment. Please note that neither the National Traffic and Motor Vehicle Safety Act (formerly at 15 U.S.C. 1381 et seq. and recently codified in Title 49 of the U.S. Code) nor the agency's regulations in Title 49 of the Code of Federal Regulations use the phrase 'safety device.' Rather, the statute refers to 'motor vehicles' and 'motor vehicle equipment.' Specifically, motor vehicle equipment is defined, in relevant part, as any system, part, or component of a motor vehicle as originally manufactured or any similar part or component manufactured or sold for replacement or improvement of such system, part, or component or as any accessory, or addition to the motor vehicle ... Under this definition, NHTSA would consider an automotive or motorcycle braking system to be an item of motor vehicle equipment. Please note that the Federal motor vehicle safety standards are issued to meet the need for safety. For example, the purpose of Standard No. 105, which regulates hydraulic brake systems of passenger cars and other specified vehicles, is 'to insure safe braking performance under normal and emergency conditions.' See S2 of Standard No. 105. Similarly, the purpose of Standard No. 122, which regulates motorcycle brake systems, is 'to insure safe motorcycle braking performance under normal and emergency conditions.' See S2 of Standard No. 122. I hope this information is helpful. If you have any further questions about NHTSA's safety standards, please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam1938OpenMr. Kenneth B. Kramer, Floyd, Kramer & Lambrecht, 220 Western Federal Savings Building, Colorado Springs, Colorado 80902; Mr. Kenneth B. Kramer Floyd Kramer & Lambrecht 220 Western Federal Savings Building Colorado Springs Colorado 80902; Dear Mr. Kramer: #This responds to your letter of April 25,1975 concerning the applicability of Federal Motor Vehicle Safety Standard No. 106-74, *Brake Hoses*, to the Wabco Westinghouse DuoMatic Coupler. #You have described the Coupler as a device which replaces the glad hand coupler now used by most manufacturers to connect truck tractor and trailer brake lines. Because the brake hose which attaches to the coupler is equipped with its own end fittings, the Coupler itself is not an end fitting, Therefore Standard No. 106-74 is inapplicable, #The Coupler is, however, subject to the requirements of 49 CFR Part 393.45 and 393.46, of which I enclose a copy. Please direct any questions you may have concerning interpretation of these requirements to the Office of the Chief Counsel, Federal Highway Administration, at 400 Seventh St., S.W., Washington, D.C. 20590. #Yours truly, Richard B. Dyson; |
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ID: aiam3905OpenMr. Andrew P. Kallman, Kallman Marketing, 205 W. Saginaw, Lansing, MI 48933; Mr. Andrew P. Kallman Kallman Marketing 205 W. Saginaw Lansing MI 48933; Dear Mr. Kallman: This responds to your letter of January 14, 1985, concerning wha regulations affect a process you intend to market for new and used cars. The process consists of grinding two parallel grooves into the lower portion of the windshield. The grooves are 2mm wide, 0.1-0.3mm deep, and are 2mm from each other. You stated that the purpose of the grooves is to improve the efficiency of the wipers and increase their life expectancy. The following discussions address the effect of our regulations on the process you described.; First, let me explain how our regulations apply to a new vehicle or t a new windshield sold as an item of replacement equipment. Our agency has issued Standard No. 205, *Glazing Materials*, which sets performance requirements for glazing materials used in new vehicles or sold as items of replacement equipment. I have enclosed a copy of the standard. If, before they are sold, the safety grooves are ground into either the windshield of a new vehicle or into a new windshield sold as an item of replacement of equipment, the person making the grooves would have to certify that the glazing continues to be in compliance with all of the requirements of Standard No. 205 for windshields. I note that the test results enclosed with your letter do not address whether the glazing would continue to comply with the requirements after it has had the safety grooves ground into it. In particular, we would urge you to determine whether the glazing would continue to comply with the requirements regarding impact and penetration resistance, optical deviation and visual distortion after the grooves have been ground into the windshield. Purchasers of a new vehicle may alter the vehicle as they please, so long as they adhere to all State requirements.; If the safety grooves are ground into the windshield of a used vehicle then Section 108 (a)(2)(A) of the National Traffic and Motor Safety Act may apply. That section provides that no manufacturer, distributor, dealer or motor vehicle repair business shall knowingly render inoperative any device or element of design installed on or in a motor vehicle in compliance with an applicable motor vehicle safety standard. Thus, none of those persons may knowingly grind the grooves into a vehicle's windshield if by so doing they would render inoperative the compliance of the vehicle's glazing with Standard No. 205. Violation of this section can result in Federal civil penalties up to $1,000 for each violation.; If you have any further questions, please let me know. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2617OpenMr. John Storz, Director of Engineering, Great Dane Trailers, Inc., Lathrop Avenue, P.O. Box 67, Savannah, GA 31402; Mr. John Storz Director of Engineering Great Dane Trailers Inc. Lathrop Avenue P.O. Box 67 Savannah GA 31402; Dear Mr. Storz: This is in response to your letter of May 5, 1977, concerning a vehicl manufacturer's responsibilities with regard to overloading.; You make a reference to a November 10, 1976, letter from the Nationa Highway Traffic Safety Administration (NHTSA) which stated that manufacturers must take reasonable steps to ensure that the vehicles they produce will not be overloaded by their users. Although we acknowledge that a manufacturer does not have direct control over the actual use of its vehicles, it does exercise indirect control over use through the vehicle's design.; The NHTSA has stated in the past that a vehicle's gross vehicle weigh rating (GVWR) is determined by the sum of its unloaded vehicle weight, 150 pounds for each designated seating position, and its rated cargo load. It is the cargo load rating that is most relevant to the problem of overloading. The rated cargo load should represent the manufacturer's assessment of the vehicle's cargo-carrying capacity and the maximum load at which the vehicle may be safely operated. A manufacturer must consider the maximum load capacity of the vehicle when it designs its cargo-carrying portion. If this is not done, the rated cargo load, and thus the GVWR, may be meaningless since the vehicle may have a cargo-carrying chamber which, if filled, would cause the vehicle to exceed its stated weight ratings. An illustration of such a situation would be a tanker truck which exceeds its GVWR when the tank is filled with a type of material appropriate for carrying in that cargo area. If the manufacturer could reasonably have anticipated that such cargo would be carried in the tanker, yet rated the vehicle with a GVWR which was less than the vehicle's weight when fully loaded with that cargo, a safety-related defect for which the manufacturer is responsible may be considered to exist.; The NHTSA does not expect manufacturers to be omniscient when it come to the use of the vehicles they produce. It does, however, expect the stated weight ratings to reflect the design of the vehicles and the uses to which they can reasonably be anticipated to be put. Where the manufacturer has reason to know the specific commodity intended to be carried in its vehicles and those vehicles have a totally enclosed cargo area, as with a tanker, the rated cargo load is relatively easy to determine.; In your particular case, your responsibility for any subsequen overloading of the vehicles it manufactures would be determined by the reasonableness of your GVWR's and gross axle weight ratings (GAWR), given the size and configuration of your vehicles and the types of loads which they could reasonably be expected to carry. Since some of your vehicles are flat beds (no enclosed cargo area) you would obviously not be able to provide weight ratings sufficiently high to prevent overloading in all instances. The design of flat beds necessarily permits overloading since the cargo area is unrestricted. Thus if the weight ratings you specify appear to have been arrived at by a good faith determination based upon the types of loads you anticipate will be carried, your responsibility with regard to weight rating specifications will have been satisfied and no safety-related defect will be attributable to you.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1191OpenMr. Joe R. Hoag, Southwest Auto Auction Inc., 3400 South Central Avenue, Phoenix, AZ 85040; Mr. Joe R. Hoag Southwest Auto Auction Inc. 3400 South Central Avenue Phoenix AZ 85040; Dear Mr. Hoag: This is in response to your letter of July 19, 1973, concernin odometer mileage statements, which questions the circumstances under which the transferor would check the statement indicating that actual mileage differs from the odometer reading. It appears from your examples that the problem arises in the transfer of vehicle ownership to you prior to auction.; The check-off provision is intended to warn the unprofessional buyer t ask for more information when the seller has checked the box indicating that he knows that the recorded mileage is incorrect. Your first example illustrates the case of a seller who considers the recorded mileage to be very low for a car of that age but has no certain information that the mileage is wrong. He should not check the box. Your second example illustrates a seller who has reasonable grounds to know (or perhaps certain knowledge) that the odometer is on its second time around, and he must check the box. The buyer is thereby warned to ask for further information about actual mileage.; Every buyer (including an auto auction) should insist on furthe information when the box is checked, so that it can make an accurate disclosure when it resells the vehicle. In the first example the auto auction would not check the box if the previous owner had not, but in the second example the auto auction would check the box, as the previous owner had and also be prepared to offer the explanation made by the original seller.; 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.