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
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ID: aiam0939OpenMr. James Tydings, Chief Engineer, Thomas Built Buses, Inc., 1408 Courtesy Road, P. O. Box 1849, High Point, NC 27261; Mr. James Tydings Chief Engineer Thomas Built Buses Inc. 1408 Courtesy Road P. O. Box 1849 High Point NC 27261; Dear Mr. Tydings:#This is in response to your recent inquiries t Berkley Sweet concerning Federal Motor Vehicle Safety Standards Nos. 101 and 108.#You ask whether S4.2.2 of Standard No. 101 applies to push-pull switches. This paragraph requires identification for the extreme positions of any heating and air conditioning system control that regulates a function over a quantitative range, and you state that you currently do not indicate the quantitative range for the heater switches.#S4.2.2 does apply to push-pull switches, and I enclose a notice that the agency published on December 3, 1971, clarifying our intent. A legend such as 'push off' and 'pull high' would be sufficient to meet the requirements of Standard No. 101. You would not have to redesign your switch cabinet to provide a slide or lever-type switch.#You also asked whether the school bus lighting description on your attached pages numbered 34 and 35 is 'legal'. The system as described conforms to the requirements of Standard No. 108 for the items listed.#Sincerely, Richard B. Dyson, Assistant Chief Counsel; |
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ID: aiam2904OpenMr. Walter J. Kulpa, Yankee Metal Products Corp., Norwalk, CT 06852; Mr. Walter J. Kulpa Yankee Metal Products Corp. Norwalk CT 06852; Dear Mr. Kulpa:#This is in response to your letter of September 18 1978, requesting a clarification of Federal Motor Vehicle Safety Standard No. 101-80, *Controls and Displays*. The National Highway Traffic Safety Administration concurs in your interpretation of S5.3.1 that any hand operated control which is mounted on the steering column does not have to meet the illumination requirements of Column 4 of Table 1.#Sincerely, Joseph J. Levin, Jr., Chief Counsel; |
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ID: aiam1781OpenHonorable William L. Scott, United States Senate, Washington, DC 20510; Honorable William L. Scott United States Senate Washington DC 20510; Dear Senator Scott: This is in response to your letter of January 28, 1975, requestin information concerning correspondence from the Virginia Automobile Dealers Association urging the issuance of a 2.5 mph bumper impact requirement by February 15, 1975.; On January 2, 1975, the National Highway Traffic Safety Administratio (NHTSA) published a Federal Register notice proposing to reduce the current 5-mph bumper impact requirements to 2.5 mph. The proposal was based primarily on the results of two agency- conducted 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. The aim of the proposed reduction in the bumper impact requirements is to allow manufacturers to produce lighter bumpers, which NHTSA studies indicate would have a favorable effect on the cost-benefit ratio.; No agreement was made with the motor vehicle industry concerning th proposal. The proposed reduction in the bumper requirements does not constitute a final statement of the NHTSA's position. All comments and data submitted in response to the proposal will be thoroughly considered before any final decision is reached.; Petitions have been received from various motor vehicle manufacturers insurance groups, and members of Congress requesting extensions of the period allowed for the submission of comments to the proposal. Although the motor vehicle manufacturers limited their request for an extension to that portion of the proposal that would not take effect until 1978, sufficient interest has been shown to indicate that more time is needed for the preparation of comments. Therefore, the comment period has been extended until March 3, 1975.; In addition, in order to allow the airing of all views, we have decide that a public hearing would be desirable. The hearing has been scheduled for February 18 and 19, 1975, at which time all interested persons are invited to present their views on the proposed amendment. I cordially invite the Virginia Automobile Dealers Association to attend and present its thoughts on this subject. We feel that the time schedule for the hearing and the comment closing date will permit the presentation of all sides of the questions involved, and enable the agency to make a final decision in time for the motor vehicle manufacturers to act with respect to the 1976 model year.; For your information, I have enclosed a copy of the Federal Registe notice scheduling the public hearing and extending the comment period. Your interest and that of the Virginia Automobile Dealers Association is greatly appreciated.; Sincerely, Barmin |
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ID: aiam4079OpenMr. M. Hayashibara, Managing Director, Certification Business Division, Mazda (North America), Inc., 24402 Sinacola Court, Farmington Hills, MI 48018; Mr. M. Hayashibara Managing Director Certification Business Division Mazda (North America) Inc. 24402 Sinacola Court Farmington Hills MI 48018; Dear Mr. Hayashibara: This responds to your letter seeking an interpretation of certain term used in Standard No. 110, *Tire selection and rims - passenger cars* (49 CFR S571.110). Specifically, you asked about the definitions of the terms 'curb weight', 'accessory weight', and 'production options weight'. These terms are defined in Standard No. 110 as follows.; The 'curb weight' of a vehicle is calculated by adding the weight o the vehicle with all of its standard equipment, including its maximum capacity of fuel, oil, and coolant to the weights of two optional items of equipment, *if the vehicle is equipped with these optional items*. The items whose weight is included in calculating the curb weight, if present on the vehicle, are air conditioning and the additional weight of an optional engine. No other optional items are included in calculating a vehicle's curb weight, even if the vehicle is equipped with such options.; The 'accessory weight' of a vehicle means the combined weight (i excess of the weight of the standard equipment items that may be replaced) of automatic transmission, power steering, power brakes, power windows, power seats, radio, and heater to the extent that these items are available as factory-installed options on that vehicle, *regardless of whether these options are actually present on the vehicle in question*. No other items of optional equipment are included in calculating the accessory weight, even if the vehicle is equipped with such options.; The 'production options weight' means the combined weight of all item of optional equipment that meet all of the following criteria:; (1) The weight of the item of optional equipment is more than fiv pounds greater than the weight of the item of standard equipment that it replaces,; (2) The optional equipment is present on the vehicle in question, and (3) The weight of the optional equipment has not previously bee considered in either the curb weight or the accessory weight.; Section S3 of Standard No. 110 lists the following examples of items o optional equipment whose weight might be considered when calculating the production options weight: heavy duty brakes, ride levelers, roof rack, heavy duty battery, and special trim. However, any item of optional equipment that meets the three criteria listed above *would* be included in calculating the production options weight, even if that item were not listed in the examples. Therefore, Mazda's understanding is correct that the weight of four-wheel drive components, aerodynamic accessories, special body styling panels, and sunroofs *are* included when calculating the production options weight.; If you have any further questions on this subject, or need mor information, please contact Steve Kratzke of my staff at this address or by telephone at (202) 426- 2992.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam0893OpenMr. Thomas S. Pieratt, Jr., Executive Secretary, Truck Equipment & Body Distributors Association, 602 Main Street, Cincinnati, OH 45202; Mr. Thomas S. Pieratt Jr. Executive Secretary Truck Equipment & Body Distributors Association 602 Main Street Cincinnati OH 45202; Dear Mr. Pieratt: This is in reply to your letters of September 25 and October 19, 1972 In your letter of September 25, you ask whether persons performing intermediate manufacturing operations are subject to the Defect Reports regulations, specifically that part of the regulations which requires the quarterly reporting of production figures (S 573.5(b)). The defect reports regulations apply to all manufacturers of complete or incomplete motor vehicles. We consider intermediate manufacturers to be within the latter category, and the regulations therefore apply to them.; Your letter of October 19 asks whether a person who installs a fift wheel in a pickup truck is considered a 'remanufacturer.' Under existing regulations, we would not consider the installation of a fifth wheel on a pickup truck to be a significant enough alteration to constitute remanufacturing. Under the recently proposed amendment to the Certification Regulations regarding the certification of altered vehicles (37 F.R. 22600, October 25, 1972), whether such a person would be an alterer and required to affix a new label to the vehicle would depend upon whether the fifth-wheel is a readily attachable component.; Yours truly, richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3246OpenMr. Earl H. Wright, Administrator, Department of Education, State of Florida, Tallahassee, FL 32304; Mr. Earl H. Wright Administrator Department of Education State of Florida Tallahassee FL 32304; Dear Mr. Wright: This responds to your recent letter requesting information concernin the legal ramifications of converting school buses with gasoline fuel systems to liquefied fuel systems.; I am enclosing a copy of a letter that we issued last year whic discusses the Federal requirements and implications of making such conversions of vehicle fuel systems. That letter should answer all of your questions. Please note that an individual or an entity such as a State agency or school board can make modifications to his or its own vehicles with impunity as far as Federal requirements are concerned, if that individual or entity performs the work. For example, district school board employees could make the conversion you desire without regard to Federal requirements, whereas a motor vehicle repair business or the L.P. gas dealer would be responsible for complying with all Federal requirements.; I hope this has been responsive to your inquiry. If you have an further questions, please contact Hugh Oates of my office at 202-426- 2992.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4583OpenThe Honorable Robert C. Smith U.S. House of Representatives Washington, DC 20515; The Honorable Robert C. Smith U.S. House of Representatives Washington DC 20515; "Dear Mr. Smith: Thank you for your letter to Secretary Skinner o behalf of your constituent, Mrs. Maureen Andrews, of Derry. You expressed concern about the absence of safety belts for school bus passengers and about the number of persons to occupy a school bus seat. I've been asked to respond to your letter since the National Highway Traffic Safety Administration (NHTSA) is responsible for administering Federal programs relating to school bus safety. The National Traffic and Motor Vehicle Safety Act of 1966 authorizes NHTSA to issue motor vehicle safety standards for new motor vehicles, including school buses. In 1974, Congress amended the Act to direct NHTSA to issue motor vehicle safety standards addressing various aspects of school bus safety, such as seating systems, windows and windshields, emergency exits, and fuel system integrity. Pursuant to that authority, NHTSA issued a comprehensive set of motor vehicle safety standards to make school buses, already a safe mode of transportation, even safer. We have considered the safety belt issue in connection with our safety standard for school bus passenger crash protection, Federal Motor Vehicle Safety Standard No. 222. Standard No. 222 requires that large school buses provide passenger crash protection through a concept called 'compartmentalization.' Providing compartmentalization entails improving the interior of the school bus with protective seat backs, additional seat padding, and better seat spacing and performance. These interior features are intended to keep occupants in their seating area and protect them during a crash. They ensure that a system of crash protection is provided to passengers independent of whether these passengers use safety belts. For your information, I have enclosed a copy of our notice terminating a rulemaking proceeding to decide whether Standard No. 222 should be amended to specify certain requirements for safety belts voluntarily installed on new large school buses. We decided not to amend the standard since these belts appear to be currently installed in a manner that ensures adequate safety performance. The notice provides a thorough discussion of the safety belt issues raised by Mrs. Andrews. As explained in the notice, school buses in this country have compiled an excellent safety record. In addition to meeting compartmentalization requirements, large school buses differ from small school buses in that they have greater mass, higher seating height and high visibility to other motorists. For all of these reasons, the need for safety belts to mitigate against injuries and fatalities in large school buses is not the same as that for smaller vehicles, such as small school buses. Thus, although Standard No. 222 does require safety belts for passengers in small school buses, we conclude that a Federal requirement for the installation of safety belts in large school buses is not justified at this time. Mrs. Andrews also asks about requirements that apply to the number of children that are allowed to sit on a bench seat. We are not authorized by Congress to regulate the number of persons that may occupy a school bus seat. However, for the purpose of ensuring that school bus manufacturers properly design their large school buses, we do specify the method for establishing the number of designated seating positions on a bench seat. The number of seating positions on a bench seat is calculated under Standard No. 222 by dividing the bench width in inches by 15 and rounding the result to the nearest whole number. Under this formula, a 39 inch bench seat has three seating positions. (39 divided by 15 = 2.6, which is rounded to 3) For small school buses, the determination of the number of positions ensures that the bench seat would have sufficient restraint systems for the maximum number of persons that should ever occupy the seat, and that the seat provides crash protection to all these persons. For large school buses, the determination ensures that the forces applied to the seat during compliance tests are reasonable reflections of the number of occupants and of the crash forces that would be involved in a real-world crash. It should be noted, however, that the number of seating positions derived from the Standard No. 222 formula is not meant to be an absolute measure of the seating capacity of the bus, irrespective of occupant size. We recognize that, in practice, school buses transport a tremendously wide variety of student sizes. For example, while a bus that may be capable of easily accommodating 65 preschool or elementary students, it may be capable of carrying only 43 high school students. When the bus is used to transport students of widely varying ages and sizes, the appropriate capacity of the bus will fall somewhere between those two values. The decision on how many passengers may be comfortably and safely accommodated, therefore, is a decision that must be reached by the bus operator, in light of the ages and sizes of passengers involved, and in accordance with state and local requirements. Since NHTSA does not have the authority to regulate how States use school buses, the agency could not preclude a State from allowing the number of passengers on a bench seat to exceed the number of designated seating positions on that seat. However, we agree with Mrs. Andrews that a student should not stand while riding in a school bus. We agree further that a student should not sit on a seat unless the student can sit fully on the seat instead of sitting only partially on the seat and thus only being partially protected by the compartmentalization. We believe that Mrs. Andrews' concerns as they apply to public schools would be best addressed by her working with the local school board and state officials. I hope this information is helpful. If you have any further questions, please do not hesitate to contact me. Sincerely, Diane K. Steed Enclosure"; |
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ID: aiam3231OpenMr. Raymond J. Salehar, Highway Safety Engineer, Motor Vehicle Administration, Maryland Department of Transportation, 6601 Ritchie Highway NE, Glen Burnie, MD 21062; Mr. Raymond J. Salehar Highway Safety Engineer Motor Vehicle Administration Maryland Department of Transportation 6601 Ritchie Highway NE Glen Burnie MD 21062; Dear Mr. Salehar: This responds to your February 8, 1980, letter asking whether it i permissible for a State to transport children to and from school on regular city transit buses. The answer to your question is yes, if the buses are on their scheduled transit routes and are transporting both school children and adults.; The National Highway Traffic Safety Administration has defined schoo bus in a way that allows buses sold for use as common carriers in urban transportation to transport school children without complying with school bus standards. This definition is located in Title 49 of the Code of Federal Regulations, Part 571.3. The agency permitted this exemption from the school bus safety standards in acknowledgment of the high costs involved in maintaining dual fleets of buses, one for school children and one for adults. Accordingly, the agency permitted cities with operating bus lines to transport children on those city buses. The agency also believes that joint bus fleets can help to conserve fuel.; The agency has made one restriction on the use of city buses t transport school children. The buses must be operating on their regular passenger routes and schedules and must not be operating on special school bus routes. Any vehicle that is operating exclusively as a school bus should be constructed in accordance with the school bus safety standards.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3661OpenMr. John C. Dobbs, Project Manager, E-Z-Go Textron, P.O. Box 388, Augusta, GA 30913-2699; Mr. John C. Dobbs Project Manager E-Z-Go Textron P.O. Box 388 Augusta GA 30913-2699; Dear Mr. Dobbs: This is in reply to your letter of February 4, 1983, telling of you wish to build a four-wheeled light weight traffic enforcement vehicle similar to a three-wheeled machine manufactured by Cushman. You have asked whether you have to meet passenger car safety standards 'or can we obtain a waiver for this vehicle only to comply with motorcycle safety standards?' You have enclosed a brochure on the vehicle you propose to modify, Textron's GX-800.; I am sorry to say that only vehicles with three wheels or less ar defined as 'motorcycles' for purposes of compliance with the Federal motor vehicle safety standards. Years ago, the agency totally excluded from the application of those standards four-wheeled vehicles with a curb weight of 1000 pounds or less such as the GX-800. However, that exclusion was terminated in the early 1970's.; A manufacturer of 10,000 vehicles or less per year may petition for temporary exemption from any safety standard where immediate compliance would cause substantial economic hardship. However, he must make a good faith effort to bring the vehicle into compliance during the exemption period. Although this would appear impossible with your vehicle because of its physical limitations, the agency has in the past exempted replicas of 1900-style vehicles where full compliance was manifestly not feasible. I enclose a copy of Title 49 Code of Federal Regulations Part 555 which sets out the exemption procedures. If your planned vehicle would have a cargo box, similar to the one on the Cushman vehicle, your vehicle could be considered a 'truck' for compliance purposes.; As a car or truck, your vehicle would also have to comply with Federa fuel economy and emissions standards. Exemptions from fuel economy standards may be sought under 49 CFR Part 525. As to the emissions standards, you should write the Environmental Protection Agency.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2973OpenMr. Charles D. Hylton, III, Director, Editorial Services, National Tire Dealers & Retreaders Association, Inc., 1343 L Street, N.W., Washington, DC 20005; Mr. Charles D. Hylton III Director Editorial Services National Tire Dealers & Retreaders Association Inc. 1343 L Street N.W. Washington DC 20005; Dear Mr. Hylton: This is in response to your letter of February 27, 1979, asking whethe tire dealers are responsible for supplying point-of-sale information concerning the Uniform Tire Quality Grading Standards (UTQG) (49 CFR 575.104) to prospective tire purchasers.; Subpart A of Part 575, *Consumer Information Regulations*, provides i section 575.6(c) (49 CFR 575.6(c)) that,; >>>'Each manufacturer of motor vehicles, each brand name owner o tires, and each manufacturer of tires for which there is no brand name owner shall provide for examination by prospective purchasers, at each location where its vehicles or tires are offered for sale by a person with whom the manufacturer or brand name owner has a contractual, proprietary, or other legal relationship, or by a person who has such a relationship with a distributor of the manufacturer or brand name owner concerning the vehicle or tire in question, the information specified in Subpart B of this part that is applicable to each of the vehicles or tires offered for sale at that location ...'<<<; The UTQG Standards, contained in Subpart B of Part 575, specify th information which must be furnished to prospective purchasers by vehicle manufacturers, tire manufacturers, and tire brand name owners (49 CFR 575.104(d)(1)(ii)).; Thus, the Consumer Information Regulations place the responsibility fo providing UTQG point-of-sale information to prospective tire purchasers on manufacturers and brand name owners rather than directly on tire dealers. The means by which tire manufacturers and brand name owners assure that UTQG information is provided for examination will be determined between these suppliers and their dealers and distributors.; You should also note that, in light of the 30-day stay granted by th U.S. Court of Appeals for the Sixth Circuit in the case of *B.F. Goodrich Co. v. Department of Transportation*, the effective dates for all requirements of the UTQG regulation, with the exception of paragraphs (d)(1)(i)(A) and (d)(1)(iii) (49 CFR 575.104(d)(i)(A) and (d)(1)(iii), are now March 31, 1979 for bias-ply tires and October 1, 1979 for bias- belted tires. Paragraph (d)(1)(i)(A), the sidewall molding requirement, and paragraph (d)(1)(iii), the first purchaser requirement, now become effective October 1, 1979 for bias-ply tires and March 31, 1980 for bias-belted tires.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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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.