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: aiam1498OpenMr. Kenji Shimizu, Mitsubishi Motors Corporation, 24300 Southfield Road, Southfield, MI 48075; Mr. Kenji Shimizu Mitsubishi Motors Corporation 24300 Southfield Road Southfield MI 48075; Dear Mr. Shimizu: This responds to your verbal request to Mr. Herlihy of this office fo a determination that a 3-point, continuous loop, Type II seat belt assembly would meet the requirements of S4.1.2.3.1(a) of Standard No. 208 if its emergency-locking retractor were mounted at the outboard floor anchorage instead of at the roof rail. The belt is routed from the fixed upper torso end, through a slip-fitting latch and pelvic section, to the retractor.; Assuming the belt assembly meets any other adjustment requirement o S4.1.2.3.1, it would conform to S7.1 of Standard No. 208 and S4.1(g) of Standard No. 209 with the emergency -locking retractor mounted at the outboard floor anchorage. The upper torso restraint would 'adjust by means of an emergency-locking retractor' within the meaning of S7.1 as long as the continuous loop permitted slack from the floor-mounted emergency-locking retractor to reach the upper torso portion of the assembly.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4360OpenMr. Y. Koyama, Niles Parts Company, Ltd., 4-9-16 Higashikojiya, Ota-Ku (144), Tokyo, Japan; Mr. Y. Koyama Niles Parts Company Ltd. 4-9-16 Higashikojiya Ota-Ku (144) Tokyo Japan; Dear Mr. Koyama: We refer to your letter of March 15, 1978, concerning the testing o hazard warning and turn signal operating units (switches) in accordance with Federal Motor Vehicle Safety Standard No. 108, Lamps, Reflective Devices, and Associated Equipment.; The purpose of requiring 3-inch wire leads on any operating unit durin testing is to permit the measurement of any voltage drop across a connector in the circuit. Since the connector is an integral part of your type of operating unit with its 'terminal-direct' connection system, the wire leads are not necessary. We, therefore, interpret the society of Automotive Engineers Standards J589 and J910, covering Hazard Warning and Turn Signal Operating Units respectively, to require 3-inch wire test leads only on those units that are supplied with integral wire leads. During the prescribed tests, voltage measurements on units such as those that you provide shall be made at the electrical contacts on the units.; Sincerely, Michael M. Finkelstein, Acting Associate Administrator fo Rulemaking; |
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ID: aiam1162OpenMr. J. T. Monk, Taylor Machine Works, Inc., P.O. Box 150, Louisville, MS 39339; Mr. J. T. Monk Taylor Machine Works Inc. P.O. Box 150 Louisville MS 39339; Dear Mr. Monk: This is in reply to your letter of May 25, 1973, to Michael Peskoe o this office, requesting clarification of the regulations regarding the certification of motor vehicles. You enclose an incomplete vehicle document concerning a particular tractor, a certification label you would affix to that tractor after its completion, a drawing of a trailer certification label, and a sample quarterly report of production figures for vehicles manufactured by your company.; Mr. Peskoe indicated to you over the phone that in meeting you certification responsibilities for these vehicles, they are certified independently of each other. It appears from your letter that this approach, which is the correct one, is the approach you are using.; With reference to your responsibilities for the certification of th tractor, if the truck does not have a certification label attached to it when you receive it, it is true that when you complete it by mounting a fifth wheel you must then attach a certification label. The label you enclose (exhibit 1) contains the necessary information in the appropriate order. You should obtain the information for the label primarily from the incomplete vehicle document, but may, as you state, rely on your own engineering judgment or contact the truck manufacturer. If, however, in relying on your own judgment you depart from the information contained in the incomplete vehicle document, you may be responsible for failures of the vehicle to conform to applicable standards and regulations.; The sample trailer certification label which you have submitted is no consistent with the certification regulations. We have taken the position that the information must be presented on the label in the form and in the order specified in the regulations. With respect to your sample label, the regulations do not presently call for a kingpin rating. Although we have just proposed to require a weight rating for the trailer coupling, this information should not now be included on the label. The regulations also do not permit ratings for tandem axles to be stated as tandem ratings. Each axle must be independently identified and a separate rating provided for it. Moreover, tire sizes are permitted to be specified only in conjunction with weight ratings. There are no provisions for the listing of plies, apart from their inclusion in a tire size designation, or for the listing of an inflation pressure. Again, information that is not specifically required cannot be inserted between items of required information, and your drawing of a trailer is not permitted unless it is placed after the required information. Finally, the regulations call for gross vehicle weight rating (the phrase 'gross trailer weight rating' is inappropriate) to follow the gross axle weight ratings, and the order in which you present this information must be reversed. I believe you should reexamine the Certification regulations in order to obtain specific guidance on the order and form of the required information.; The sample quarterly production report you submit conforms to th requirements of section 573.5(b) of the Defect Reports regulations. However, that section requires only the reporting of the number of vehicles, identified by make, model, and model year (if appropriate). While we are happy to receive the additional information you provide, you are not required to furnish it to us.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2963OpenMr. Paul Utans, Subaru of America, Inc., 7040 Central Highway, Pennesauken, (sic) NJ 08109; Mr. Paul Utans Subaru of America Inc. 7040 Central Highway Pennesauken (sic) NJ 08109; Dear Mr. Utans:#I regret the delay in responding to your September 12 1978, letter requesting interpretation of Federal Motor Vehicle Safety Standard 101-80, *Controls and Displays*. The responses to your specific questions regarding the compliance of your prototype monitor of vehicle systems are as follows:#1. When there is no problem with the vehicle systems included in the monitor, only the outline of a car is visible. The displays for items such as oil and electrical charge would not be illuminated. You asked if the monitor in its 'no problem' model would comply with FMVSS 101-80. The answer is yes. There is no requirement that the displays be continuously illuminated.#2. On the monitor, the high beam symbol would be oriented so that it pointed upward. You asked whether this complies with the standard even though the symbol appears in Table 2 of the standard pointing to the left. The answer is yes. The requirement is section 5.2.3 that the display symbol appear preceptually (sic) upright to the driver was not intended to apply to the situation in which the symbol is used in conjunction with a car diagram of the type in your monitor. In such situations, it would be more confusing to place the symbol in the upright position than to orient the symbol so that it bears the same relationship to the diagram as the symbolized equipment does to the actual vehicle.#Sincerely, Frank Berndt, Acting Chief Counsel; |
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ID: aiam3671OpenMr. David E. Williams, Marketing Manager, Smithers Scientific Services, Inc., 1150 N. Freedom Street, P.O. Box 351, Ravenna, OH 44266; Mr. David E. Williams Marketing Manager Smithers Scientific Services Inc. 1150 N. Freedom Street P.O. Box 351 Ravenna OH 44266; Dear Mr. Williams: This responds to your letter to Mr. Kratzke of my staff, asking abou the requirements of Safety Standard No. 119, *New Pneumatic Tires for Motor Vehicles Other Than Passenger Cars* (49 CFR 571.119) (copy enclosed). Specifically, you are representing a towing trailer manufacturer which would like to mount aircraft tires on its trailers as original equipment.; Paragraph S5.1.1 of Standard No. 120, *Tire Selection and Rims fo Motor Vehicles Other Than Passenger Cars*, 49 CFR 571.120) specifies that new trailers shall be equipped with tires that meet the requirements of either Safety Standard No. 109, which applies to passenger car tires, or Safety Standard No. 119. Your client intends to meet this requirement by equipping the trailers with tires which comply with Standard No. 119. However, your tests showed that the aircraft tires which the trailer manufacturer wants to use on the trailers could not pass the high speed test in Standard No. 119. You asked if the high speed test requirement could be avoided if those tires were speed-restricted to 55 miles per hour (mph) or less.; The answer is yes. Speed restrictions may only be placed on a tire b the tire manufacturer, and may only be specified at 35, 50, or 55 mph. To create a speed-restriction, paragraph S6.5(e) of Standard No. 119 requires the tire manufacturer to mark the notation 'max speed 55 mph' on both sidewalls. When a tire is so marked, it is speed-restricted for purposes of Standard No. 119. Paragraph S6.3 of Standard No. 119 states that the high speed test requirement 'applies only to motorcycle tires and non- speed-restricted tires.' Accordingly, no high speed tests are conducted on tires which are speed-restricted.; You should, however, be aware of the requirements of 49 CFR Part 567 *Certification* (copy enclosed). Specifically, section 567.4(g)(3) and (4) requires a vehicle manufacturer to show a gross vehicle weight rating (GVWR) and gross axle weight rating (GAWR) for each axle on the certification label required to appear on all new vehicles. The NHTSA requires that the GVWR and GAWR placed on the certification label be unqualified by any speed restrictions and be based on the 60 mph capabilities assigned to the tires and rims by the Tire & Rim Association. Other GVWR and GAWR values may be assigned by the manufacturer, but they must be listed after the information required on the certification label, and they do not form the basis for testing a vehicle's compliance with safety standards, such as Standard No. 120.; Finally, I wish to emphasize that if these towing trailers are likel to be used at speeds in excess of 55 mph, the use of tires which are speed-restricted to 55 mph might well be determined to constitute a safety-related defect in the vehicle, under the terms of the National Traffic and Motor Vehicle Safety Act of 1966, as amended (15 U.S.C. 1381 *et seq*.). When a determination is made that a vehicle or item of equipment contains a safety-related defect, section 154 of the Safety Act (15 U.S.C. 1414) requires the manufacturer to repair or replace the defective vehicle or item without charge to the purchaser.; Should you need any further information on this matter, please contac Mr. Kratzke at (202) 426-2992.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3221OpenMr. J. Leftrook, Jr., President, G. Mack Industries, Ltd., Suite No. 3, 933 McLeod Avenue, Winnipeg, Manitoba, Canada R2G OY4; Mr. J. Leftrook Jr. President G. Mack Industries Ltd. Suite No. 3 933 McLeod Avenue Winnipeg Manitoba Canada R2G OY4; Dear Mr. Leftrook: This is in reply to your letter of February 18, 1980, asking about th legality in the United States of a lamp with the words 'DON'T PASS' which you are presently manufacturing for school buses in Canada. The lamp is intended for mounting on both the front and rear of the bus.; Such a lamp is not required in this country under Federal law. Its us as original equipment on U.S. school buses would not be prohibited by Federal Motor Vehicle Safety Standard No. 108, *Lamps, Reflective Devices and Associated Equipment*, since its installation would not appear to impair the effectiveness of required lighting equipment. Its legality would be determined by that of the State in which the bus is registered and operated, and therefore, you should contact the individual State for their opinion in this matter.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2060OpenMr. Stephen L. Oesch, Communications Department, Insurance Institute for Highway Safety, Watergate Six Hundred, Washington, DC 20037; Mr. Stephen L. Oesch Communications Department Insurance Institute for Highway Safety Watergate Six Hundred Washington DC 20037; Dear Mr. Oesch: This is in response to your letter of June 27, 1975, inquiring as t the legislative basis for the National Highway Traffic Safety Administration's (NHTSA) May 13, 1975, amendment of Standard No. 215, *Exterior Protection*, to delay for 1 year the application of the low-corner impact requirements to vehicles with wheelbases exceeding 120 inches (40 FR 20823).; The sections of the National Traffic and Motor Vehicle Safety Act (Pub L. 89-563) supporting the agency's May 13, 1975, action are sections 103(a) and 103(f) (15 U.S.C. 1392(a), 1392(f)). Section 103(a) directs the Secretary to establish appropriate motor vehicle safety standards which are practicable, meet the need for motor vehicle safety, and are stated in objective terms. The 1-year delay in application of the low-corner requirements to 'full-sized' cars was granted as a means of providing Chrysler with relief from the serious financial difficulties it was experiencing. Based upon the information presented by Chrysler to the agency, compliance with the low-corner requirements by its 'full-sized' cars would endanger its ability to continue functioning as an automobile manufacturer. Imposition of these pendulum requirements on Chrysler was therefore not considered practicable.; Granting the relief contained in the May notice meets the need fo motor vehicle safety in that jeopardizing the existence of Chrysler as one of the United States' major motor vehicle manufacturers would have a distinct impact on the technological advances fostered by competition among these members of the motor vehicle industry. In addition, loss of Chrysler as a viable competitor in the motor vehicle market would almost certainly have an unhealthy economic impact.; Section 103(f) of the Traffic Safety Act specifies factors to b considered in prescribing standards: that they be 'reasonable, practicable, and appropriate for the particular type of motor vehicle.' On the basis of the information submitted by Chrysler explaining the effect of this requirement on it as a motor vehicle manufacturer, the agency determined that a delay of 1 year in the imposition of the low-corner hit to the type of vehicles in question would be reasonable, in light of these policy considerations.; The NHTSA did not follow the procedures prescribed in section 113 o the Traffic Safety Act relating to cost information in its handling of Chrysler's request to delay for one year the application of the low-corner impact requirements to vehicles with wheelbases exceeding 120 inches since the Chrysler request did not constitute an objection 'to an action of the Secretary.' The low-corner impact requirements were issued in 1971 and it was not that action of the Secretary which was opposed by Chrysler. Chrysler, in its petition, has requested that new action be taken to provide them with some relief from their existing financial burdens.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam2430OpenMr. Kerry G. Lund, United Recreational Products, Inc., Country Road & Highway 35, Webster, WI 54893; Mr. Kerry G. Lund United Recreational Products Inc. Country Road & Highway 35 Webster WI 54893; Dear Mr. Lund: This responds to your July 16, 1976, request for information on th requirements for a manufacturer of a light utility trailer which is designed to carry snowmobiles. I regret that we have not responded sooner.; The information you request appears in Title 49 of the Code of Federa Regulations, and I enclose an information sheet which explains how this material may be acquired.; Part 566, *Manufacturer Identification (49 CFR Part 566), specifie identification information which must be submitted to the NHTSA by manufacturers of vehicles and equipment regulated by our standards.; Part 567, *Certification* (49 CFR Part 567), specifies the content an location of the certification label or tag which must be attached to motor vehicles regulated by our standards.; At this time the only Federal safety standards applicable to al trailers are Standard No. 108, *Lamps, Reflective Devices, and Associated Equipment*, and Standard No. 120, *Tire and Rim Selection for Vehicles Other Than Passenger Cars*. The enclosed information sheet also explains how to acquire those regulations.; Standard No. 121, *Air brake systems*, became effective on January 1 1975, in the case of trailers which the manufacturer has decided to equip with air brakes. Thus trailers which you manufacture on or after January 1, 1975, which utilize air brakes must meet the air brake standard.; After you have reviewed the regulations I have referred to, pleas contact me if you have any further questions.; Yours truly, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam2125OpenMr. Charles F. Butler, President, Butler Associates, Inc., Post Office Box K, Washington, DC 20014; Mr. Charles F. Butler President Butler Associates Inc. Post Office Box K Washington DC 20014; Dear Mr. Butler: I am writing in response to your September 22, 1975, letter concernin safety standards applicable to your 1975 Ford Custom Wagon. Your letter was referred to this agency by Senator Magnuson.; I am enclosing a brochure entitled *Standards* which briefly lists th Federal motor vehicle safety standards and the vehicles to which they apply.; Most of the standards were initially applied to passenger cars becaus they accounted for the vast majority of traffic deaths and injuries. Your Custom Wagon is classified for the purposes of our standards as a multi-purpose passenger vehicle (MPV). Each particular type of vehicle, such as a car, small or large truck, van, bus, or motorcycle, has its own design characteristics and configuration, with widely different causes of crash injury and fatality. Since the original Federal standards were established in 1967, effective January 1, 1968, we have been in the process of extending the applicability of our current standards and of preparing new standards where appropriate to other vehicle types, including MPV's. For example, effective January 1, 1976, all trucks and MPV's with a Gross Vehicle Weight Rating of 10,000 pounds or less will be required to be equipped with combination lap and shoulder belts with inertial retractors, just as has been required of passenger cars since September 1973. With the constantly improving accident investigation information on how and why particular injuries occur in particular types of vehicles, we expect to be able to determine which safety items are necessary and will do the most good on all vehicles. We will then issue appropriate standards as rapidly as possible.; I appreciate your concern over the safety of our motor vehicles. Sincerely, James B. Gregory, Administrator |
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ID: aiam0118OpenMr. Max Walter, Citroen Cars Corporation, 415-421 Third Avenue, Brooklyn, NY 11215; Mr. Max Walter Citroen Cars Corporation 415-421 Third Avenue Brooklyn NY 11215; Dear Mr. Walter: By your letter of October 8, 1968 you ask if the glazing material i the rear window of passenger cars can be 4 millimeters thick and be in compliance with Federal Motor Vehicle Standard No. 205, Glazing Materials - Passenger Cars, Multipurpose Passenger Vehicles, Motorcycles, Trucks, and Buses.; Standard No. 205 requires that glazing materials conform to the AS Standard Z26.1-1966. The ASA standard Z26.1- 1966 does not set forth how thick glazing material must be but requires the glass used to meet certain tests, depending on the type of vehicle the glass is being used in and the location of the glass in that vehicle.; Sincerely, Robert M. O'Mahoney, Assistant Chief Counsel for Regulations |
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.