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: aiam2407OpenHonorable Carl Albert, Speaker of the House of Representatives, Washington, DC 20515; Honorable Carl Albert Speaker of the House of Representatives Washington DC 20515; Dear Mr. Speaker: This letter is to inform you that the effective date that has bee established for implementation of the Federal bumper standard issued pursuant to Title I of the Motor Vehicle Information and Cost Savings Act (Pub. L. 92-513) is more than 18 months after the date on which the final rule was promulgated. Section 102(d)(2) of Title I directs the National Highway Traffic Safety Administration (NHTSA) to provide Congress with a detailed explanation of the effective date of the Federal bumper standard where more than 18 months leadtime has been provided. This letter describes the basis for the agency's decision to establish an effective date 30 months after the standard's date of promulgation.; The NHTSA, on March 4, 1976, published a Federal bumper standard, 4 CFR Part 581, pursuant to Title I of the Act. Title I directs the NHTSA to develop standards that 'seek to obtain the maximum feasible reduction of costs to the public and to the consumer' occasioned by low-speed collisions. Part 581 moves toward accomplishing this goal by limiting the damage that is allowed to vehicle bumpers and exterior surfaces in low-speed crashes. Petitions for reconsideration of the rule have been submitted and will be responded to shortly. The agency's response to these petitions will complete the final rulemaking step in the issuance of the standard.; On March 12, 1975, the NHTSA proposed three alternative effectiv dates--September 1 of 1976, 1977, or 1978--for implementation of the Part 581 requirements. Interested persons were asked to comment on the feasibility of satisfying the standard's damage criteria within those alternative time periods. Comments were received from seven motor vehicle manufacturers on the subject of Part 581's initial effective date. Five manufacturers specifically urged an effective date of September 1, 1978, stating that earlier compliance would impose high development costs and involve the use of bumper systems that have not been optimized. One manufacturer did not specifically favor any of the suggested implementation dates, but stated that early compliance could only be achieved if the standard were modified. Only one manufacturer said that it could meet the standard earlier than 1978. It stated that it could satisfy Part 581 by September 1, 1977, and emphasized that significant costs would be involved if an earlier effective date were prescribed.; During the phase effective on September 1, 1978, the Part 581 standar will prohibit any damage to vehicle exterior surfaces during prescribed front and rear 5 mph pendulum and barrier crash tests. Only the bumper itself will be permitted to sustain damage. Compliance with these requirements, according to manufacturers, will entail a degree of redesign and retooling. The requested effective dates indicate the amount of leadtime considered necessary to accomplish these vehicle changes in a cost-efficient manner.; Since the purpose of the Title I bumper standard is to achieve a cos savings for consumers, all costs involved in its implementation must be closely examined. Based upon the information submitted by manufacturers, compliance with Part 581 would be significantly more costly before September 1, 1978. The agency has determined that such additional costs would not be justified as they would undermine the benefits to be provided to consumers. A September 1, 1978, effective date is appropriate since it will give manufacturers adequate leadtime to develop and optimize bumper systems that meet the performance level of Part 581.; In keeping with the Act's requirement that the agency publish it reasons for providing more than 18 months leadtime, the basis for the NHTSA's decision to specify a September 1, 1978, effective date is thoroughly explained in the *Federal Register* notice establishing the Part 581 bumper standard as a final rule.; Sincerely, John W. Snow, Administrator |
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ID: aiam5022OpenMr. Hal Balzak 28025 N. Sarabande Lane #1216 Canyon Country, CA 91351; Mr. Hal Balzak 28025 N. Sarabande Lane #1216 Canyon Country CA 91351; "Dear Mr. Balzak: This responds to your letter concerning Federal Moto Vehicle Safety Standard No. 201, Occupant Protection in Interior Impact. I apologize for the delay in our response. You stated that you have received a copy of this standard and would like clarification of two issues. Your questions are addressed below. Your first question asked whether Standard No. 201 applied to passenger cars manufactured between January 1, 1968 and September 1, 1981. The answer to this question is yes, the standard applied to all passenger cars manufactured on or after January 1, 1968. Your second question asked whether Standard No. 201 applies to instrument panels manufactured for replacement of damaged units. The answer to this question is that, by its own terms, Standard No. 201 applies only to new motor vehicles. This means that the standard applies to original equipment components, including instrument panels, but not to replacements for those components. However, you should be aware of an important provision in Federal law. Section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1397(a)(2)(A)) provides that '(n)o manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard. . . .' This provision applies to both new and used vehicles. You specifically asked about the replacement of damaged instrument panels. I note that the Safety Act does not require a manufacturer, distributor, dealer or repair business to return a vehicle to compliance with a standard if a device or element of design has been 'rendered inoperative' by another agent, such as a crash. The prohibition of section 108(a)(2)(A) does not apply to individual owners who alter their own vehicles. Thus, individual owners may install any item of motor vehicle equipment regardless of its effect on compliance with Federal motor vehicle safety standards. However, NHTSA encourages vehicle owners not to tamper with the safety equipment installed on their vehicles. I hope this information is helpful. If you have further questions, please feel free to contact Edward Glancy of my staff at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam5021OpenMr. Hal Balzak 28025 N. Sarabande Lane #1216 Canyon Country, CA 91351; Mr. Hal Balzak 28025 N. Sarabande Lane #1216 Canyon Country CA 91351; "Dear Mr. Balzak: This responds to your letter concerning Federal Moto Vehicle Safety Standard No. 201, Occupant Protection in Interior Impact. I apologize for the delay in our response. You stated that you have received a copy of this standard and would like clarification of two issues. Your questions are addressed below. Your first question asked whether Standard No. 201 applied to passenger cars manufactured between January 1, 1968 and September 1, 1981. The answer to this question is yes, the standard applied to all passenger cars manufactured on or after January 1, 1968. Your second question asked whether Standard No. 201 applies to instrument panels manufactured for replacement of damaged units. The answer to this question is that, by its own terms, Standard No. 201 applies only to new motor vehicles. This means that the standard applies to original equipment components, including instrument panels, but not to replacements for those components. However, you should be aware of an important provision in Federal law. Section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1397(a)(2)(A)) provides that '(n)o manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard. . . .' This provision applies to both new and used vehicles. You specifically asked about the replacement of damaged instrument panels. I note that the Safety Act does not require a manufacturer, distributor, dealer or repair business to return a vehicle to compliance with a standard if a device or element of design has been 'rendered inoperative' by another agent, such as a crash. The prohibition of section 108(a)(2)(A) does not apply to individual owners who alter their own vehicles. Thus, individual owners may install any item of motor vehicle equipment regardless of its effect on compliance with Federal motor vehicle safety standards. However, NHTSA encourages vehicle owners not to tamper with the safety equipment installed on their vehicles. I hope this information is helpful. If you have further questions, please feel free to contact Edward Glancy of my staff at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam2464OpenMr. John J. Giesguth, Director, Bureau of Pupil Transportation, Division of Field Services, Department of Education, P.O. Box 2019, Trenton, New Jersey 08625; Mr. John J. Giesguth Director Bureau of Pupil Transportation Division of Field Services Department of Education P.O. Box 2019 Trenton New Jersey 08625; Dear Mr. Giesguth: This is in reply to your letter of September 9, 1976, requestin information of the legal aspects of the change in the definition of 'school bus.'; Effective April 1, 1977, the definition of 'school bus' in Title 49 o the Code of Federal Regulation (49 CFR S571.3) will read as follows:; >>>'School bus' means a bus that is sold or introduced in interstat commerce, for purposes that include carrying students to and from school or related events, but does not include a bus designed and sold for operating as a common carrier in urban transportation.<<<; The definition of 'bus' will continue to read a follows: >>>'Bus' means a motor vehicle with motive power, except a trailer designed for carrying more than 10 persons.<<<; The new definition of school bus will include many of the van-typ vehicles that are classified as Type II school vehicles under Highway Safety Program Standard No. 17. If a Type II van is designed to carry more than 10 persons, and if it is sold for purposes that include 'carrying students to and from school or related events,' it will have to be sold with all the equipment specified for school buses by the Federal Motor Vehicle Safety Standards. It will therefore have to have school bus lights as specified by the standard on lighting (49 CFR S571.108).; Our experience with the comparative accident patterns of Type I an Type II buses does not justify the use of different lighting systems for the two types. In view of Congress's expressed desire to have the school bus standards uniformly applicable to busses of all sizes, we consider it appropriate to apply the lighting standard to all school buses.; We understand your concern with the effects that the newly applicabl requirements will have on your purchase of Type II vans. However, we are persuaded that the requirements are reasonable and that they will protect school children.; If we can be of further assistance, please let us know. Sincerely, John W. Snow, Administrator |
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ID: aiam2465OpenMr. John J. Giesguth, Director, Bureau of Pupil Transportation, Division of Field Services, Department of Education, P.O. Box 2019, Trenton, NJ 08625; Mr. John J. Giesguth Director Bureau of Pupil Transportation Division of Field Services Department of Education P.O. Box 2019 Trenton NJ 08625; Dear Mr. Giesguth: This is in reply to your letter of September 9, 1976, requestin information on the legal aspects of the change in the definition of 'school bus.'; Effective April 1, 1977, the definition of 'school bus' in Title 49 o the Code of Federal Regulations (49 CFR S 571.3) will read as follows:; >>>'School bus' means a bus that is sold or introduced in interstat commerce, for purposes that include carrying students to and from school or related events, but does not include a bus designed and sold for operation as a common carrier in urban transportation.<<<; The definition of 'bus' will continue to read as follows: >>>'Bus' means a motor vehicle with motive power, except a trailer designed for carrying more than 10 persons.<<<; The new definition of school bus will include many of the van- typ vehicles that are classified as Type II school vehicles under Highway Safety Program Standard No. 17. If a Type II van is designed to carry more than 10 persons, and if it is sold for purposes that include 'carrying students to and from school or related events,' it will have to be sold with all the equipment specified for school buses by the Federal Motor Vehicle Safety Standards. It will therefore have to have school bus lights as specified by the standard on lighting (49 CFR S571.108).; Our experience with the comparative accident patterns of Type I an Type II buses does not justify the use of different lighting systems for the two types. In view of Congress's expressed desire to have the school bus standards uniformly applicable to buses of all sizes, we consider it appropriate to apply the lighting standard to all school buses.; We understand your concern with the effects that the newly applicabl requirements will have on your purchase of Type II vans. However, we are persuaded that the requirements are reasonable and that they will protect school children.; If we can be of further assistance, please let us know. Sincerely, John W. Snow, Administrator |
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ID: aiam2351OpenMr. Edmund Downey, Suplicy Cacique Trading Co., Inc., 120 Wall St., New York, New York 10005; Mr. Edmund Downey Suplicy Cacique Trading Co. Inc. 120 Wall St. New York New York 10005; Dear Mr. Downey: #This is in response to your telephone conversation o June 3 and June 21, 1976, with Mark Schwimmer of this office concerning the application of the Federal motor vehicle safety standards to components of hydraulic brake systems for passenger cars. #The performance of hydraulic brake systems for passenger cars is the subject of Standard No. 105-75. The only standards that apply directly to components of a hydraulic drake system are Standard No. 106-74, *Brake Hoses*, and standard No. 116, *Motor Vehicle Brake Fluids*. Standard No. 106-74 applies to brake hoses, brake hose end fittings, and brake hose assemblies. These terms are defined in the standard as follows: #>>>'Brake hose means a flexible conduit, other than a vacuum tubing connector, manufactured for use in a brake system to transmit or contain the fluid pressure or vacuum used to apply force to a vehicle's brakes. #'Brake hose end fitting' means a coupler, other than a clamp, designed for attachment to the end of a brake hose. #'Brake hose assembly' means a brake hose, with or without armor, equipped with end fittings for use in a brake system, but does not include an air or vacuum assembly prepared by the owner or operator of a used vehicle, by his employee, or by a repair facility, for installation in that used vehicle. #'Vacuum tubing connector' means a flexible conduit of vacuum that (i) connects metal tubing to metal tubing in a brake system, (ii) is attached without end fittings, and (iii) when installed, has an unsupported length less than the total length of those portions that cover the metal tubing.<<< #Please note that vacuum tubing connectors are not presently subject to any safety standards. #Section 114 of the National Traffic and Motor Vehicle Safety Act of 1966, as amended, specifies that #>>>Every manufacturer or distributer of a motor vehicle or motor vehicle equipment shall furnish to the distributer or dealer at the time of delivery of such vehicle or equipment by such manufacturer or distributer the certification that each such vehicle or item of motor vehicle equipment conform to all applicable Federal motor vehicle safety standards. In the case of an item of motor vehicle equipment such certification may be in the form of a container in which such item is delivered... .<<< #With respect to an item of motor vehicle equipment for which there exists no applicable Federal motor vehicle safety standard, the National Highway Traffic Safety Administration interprets this section as not requiring any certification. Sincerely, Frank A. Berndt, Acting Chief Counsel; |
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ID: aiam4485OpenMr. A. L. Bragg Laboratory Manager Truck-Lite Co., Inc. 310 East Elmwood Avenue Falconer, NY 14733; Mr. A. L. Bragg Laboratory Manager Truck-Lite Co. Inc. 310 East Elmwood Avenue Falconer NY 14733; Dear Mr. Bragg: This is in reply to your letter of June 22, l988, t Mr. Vinson of this Office asking for an interpretation of Motor Vehicle Safety Standard No. 108. It is your understanding that for purposes of measuring the effective projected illuminated area of a lens, the reflex area, if any, must be subtracted from the total lens area. Your company manufactures a combination lamp which 'has four square inches of reflector area and eight square inches of stop, tail and turn area.' You have asked if you may advise your customers that this lamp may be used on vehicles whose overall width is 80 inches or more: 'A) Singularly (that is one on each side of the vehicle in the rear) as a stop, turn, tail and reflex reflector? B) In combination of two's or three's (on each side of the rear of the vehicle), provided that the lamps are separated by at least twenty-two inches?' Your understanding is correct, that the effective projected illuminated lens area must be determined without reference to any reflex reflector that may be combined with it. If the turn signal function in your lamp is met by one compartment, your lamp is acceptable under 'A).' But if the turn signal function is met by more than one compartment, your lamp would not be acceptable as the area of each compartment is less than l2 square inches. With regard to 'B),' the lamps could be used in combinations of twos and threes if they are mounted more than 22 inches apart but could not be used if mounted closer than 22 inches. You also asked about the relationship to paragraph S4.1.1.7. This paragraph covers replacement equipment only, without reference to its location on a vehicle. It applies only to turn signal lamps intended to replace original equipment turn signal lamps on vehicles manufactured in accordance with SAE Standard J588d, June l966. The current original equipment requirement is SAE Standard J588e September l970. You should be aware that the Truck Safety Equipment Institute has petitioned for rulemaking the effect of which would be to extend the l2-inch requirement to lamps used on all wide vehicles without reference to the 22-inch spacing. At present the agency is reviewing this petition. I hope that this answers your questions. Sincerely, Erika Z. Jones Chief Counsel /; |
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ID: aiam4480OpenMr. A. L. Bragg Laboratory Manager Truck-Lite Co., Inc. 310 East Elmwood Avenue Falconer, NY 14733; Mr. A. L. Bragg Laboratory Manager Truck-Lite Co. Inc. 310 East Elmwood Avenue Falconer NY 14733; Dear Mr. Bragg: This is in reply to your letter of June 22, l988, t Mr. Vinson of this Office asking for an interpretation of Motor Vehicle Safety Standard No. 108. It is your understanding that for purposes of measuring the effective projected illuminated area of a lens, the reflex area, if any, must be subtracted from the total lens area. Your company manufactures a combination lamp which 'has four square inches of reflector area and eight square inches of stop, tail and turn area.' You have asked if you may advise your customers that this lamp may be used on vehicles whose overall width is 80 inches or more: 'A) Singularly (that is one on each side of the vehicle in the rear) as a stop, turn, tail and reflex reflector? B) In combination of two's or three's (on each side of the rear of the vehicle), provided that the lamps are separated by at least twenty-two inches?' Your understanding is correct, that the effective projected illuminated lens area must be determined without reference to any reflex reflector that may be combined with it. If the turn signal function in your lamp is met by one compartment, your lamp is acceptable under 'A).' But if the turn signal function is met by more than one compartment, your lamp would not be acceptable as the area of each compartment is less than l2 square inches. With regard to 'B),' the lamps could be used in combinations of twos and threes if they are mounted more than 22 inches apart but could not be used if mounted closer than 22 inches. You also asked about the relationship to paragraph S4.1.1.7. This paragraph covers replacement equipment only, without reference to its location on a vehicle. It applies only to turn signal lamps intended to replace original equipment turn signal lamps on vehicles manufactured in accordance with SAE Standard J588d, June l966. The current original equipment requirement is SAE Standard J588e September l970. You should be aware that the Truck Safety Equipment Institute has petitioned for rulemaking the effect of which would be to extend the l2-inch requirement to lamps used on all wide vehicles without reference to the 22-inch spacing. At present the agency is reviewing this petition. I hope that this answers your questions. Sincerely, Erika Z. Jones Chief Counsel; |
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ID: aiam1280OpenMr. Roy Case, Twin Coach Highway Products Incorporated, Kent, OH 44240; Mr. Roy Case Twin Coach Highway Products Incorporated Kent OH 44240; Dear Mr. Case: Thank you for your letter of August 22, 1973, concerning th requirements of Federal Motor Vehicle Safety Standard No. 217, Bus Window Retention and Release.; Following are answers to your four questions: >>>1. In a phone conversation with Richard Dyson on September 26 yo explained that the window mechanism in question (which you mentioned you are no longer using) requires the release of both mechanisms before the window releases -- that is, before the window will no longer conform to the retention requirements in paragraph S5.1, S5.1.1, and S5.1.2 of the standard. In this case, only one of the force applications necessary to operate both mechanisms need differ by 90 degrees to 180 degrees from the direction of the original push-out motion of the emergency exit.; 2. You are correct that the post in front of the window is not a obstruction so long as it permits passage of the ellipsoid. However, when a post cuts a window opening into two segments as shown in your enclosed sketch, only the segment that passes the ellipsoid, not the entire window opening, may count toward the measurement of total area specified in paragraph S5.2.; 3. Although Figure 3C shows only the boundaries for high and low forc access regions when the bus is upright (and when an obstacle is between the occupant and the unit), these same dimensions are these that are to be applied when the bus is overturned on either side, with the side on which the bus is resting being considered as the floor. The transposition of these dimensions is illustrated to some extent in Figure 3D.; Whether or not both rear windows must be made into emergency exit rests solely on whether both windows are necessary for the bus to meet the unobstructed opening requirements, and the emergency exit release requirements of S5.3 and S5.5 when the bus is upright and overturned on either side.; 4. The cut-off date for windows which do not comply with the standar is that of the date of manufacture of the bus in which the window is installed. All buses manufactured on or after September 1, 1973, must comply with the requirements of Standard No. 217.<<<; If I can be of further assistance, please do not hesitate to ask. Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicle Programs |
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ID: aiam4184OpenMr. William H. Spain, National Management, Inc., P.O. Box 3528, Montgomery, AL 36109; Mr. William H. Spain National Management Inc. P.O. Box 3528 Montgomery AL 36109; Dear Mr. Spain: Thank you for your letter of May 20, 1986, asking how our regulation would apply to a wooden steering wheel you manufacture. You explained that you use a standard steering wheel with a steel outer rim. The steel outer rim is then veneered with wood, which is covered with a protective finish. The finished wheel will then be used as an item of original equipment by a vehicle manufacturer. I hope the following discussion answers your question.; The agency has issued two Federal Motor Vehicle Safety Standards tha set occupant crash protection performance requirements for vehicle steering systems, which includes the steering wheel. Those standards are Standard No. 203, *Impact Protection for the Driver from the Steering System*, and Standard No. 204, *Steering Column Rearward Displacement*. Those two standards do not regulate the types of material that may be used in the steering wheel, but instead set performance requirements that the steering systems must meet under certain test conditions. Therefore, a manufacturer may use any material in its steering wheel, as long as the steering system still complies with the performance requirements of Standard Nos. 203 and 204.; If you have any further questions, please let me know. Sincerely, Erika Z. Jones, 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.