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: nht73-6.18OpenDATE: 03/02/73 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Ford Motor Company COPYEE: J. G. WOMACK; MR. TOMS; MR. HARTMAN; MR. CARTER TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of February 16, 1973, concerning the safety standard applicable to the sling for the upper torso belt used in Ford's 1974 model restraint system. The schematic drawing attached to your letter shows that the sling attaches to the roof rail and serves the function of an upper torso belt anchorage. We agree with you that the sling is subject to the requirements of Standard No. 210 and not to the requirements of Standard No. 209. Although the sling is made of fabric webbing, its function is that of an anchorage and it is therefore subject to the anchorage standard. Yours truly, Ford Motor Company February 16, 1973 Douglas W. Toms Administrator National Highway Traffic Safety Administration Dear Mr. Toms: An inquiry has been raised by certain of our suppliers with regard to one feature of Ford's 1974 model year restraint system. Ford believes an interpretative statement by the Administration would be desirable to resolve questions that now exist, or may in the future arise, with regard to this type of item. The attached schematic shows a typical 1974 Ford restraint system. The non-detachable upper torso portion of the restraint system is looped through a "sling" attached to the roof rail of the vehicle. The "sling" is depicted in more detail in View-A of the attached drawing. This sling is an an anchorage for purposes of Standard No. 210 for several reasons. First, Standard No. 210 defines a seat belt anchorage as the provision for transferring seat belt assembly loads to the vehicle structure. The sling clearly serves this function. Second, as the sling location determines the angle at which the upper torso restraint crosses the occupant's chest, the sling would fall within the acceptable range for upper torso anchorage locations specified in Standard No. 210. As we have chosen to use webbing in the sling (as opposed to a cable or some such material), the concern expressed involves the question as to whether a potential conflict could arise in interpreting what requirements this sling must meet. If the sling were to be considered by an independent testing laboratory to be part of the seat belt assembly as defined in Standard No. 209, it would apply the webbing requirements set forth in Section S4.2 of Standard No. 209 to the sling webbing. We would urge that it should not be necessary to meet these webbing requirements as the sling is part of the anchorage and meets the strength requirements of Standard No. 210. We request, therefore, that the Administration concur in Ford's interpretation that the sling as depicted in the attached schematic is a part of the anchorage and not a part of the seat belt assembly. Respectfully submitted, J. C. ECKHOLD Director Automotive Safety Office Attachment (Graphics omitted) (Graphics omitted) FORD-MERCUPY MODEL 65 SHOWN TORINO-MONTEGO-COUGAR T-BIRD-MARK IV-LINCOLN MODELS 65 TYPICAL |
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ID: nht73-6.19OpenDATE: 05/22/73 FROM: AUTHOR UNAVAILABLE; James E. Wilson; NHTSA TO: Ford Motor Company TITLE: FMVSS INTERPRETATION TEXT: By petition for rulemaking dated November 15, 1973, the Ford Motor Company requested an amendment of Motor Vehicle Safety Standard No. 210 with respect to the strength required of the anchorages for the pelvic portion of a Type 2 seat belt assembly. After considering the merits of the requested amendment, we have decided to deny your petition. As stated in your petition, the anchorages for the pelvic portion of a Type 2 assembly are presently subject to two strength requirements under Standard 210. Section S4.2.2 provides that, when tested in conjunction with the upper torso anchorage, the pelvic anchorages must withstand a force of 3,000 pounds applied through the seat belt assembly. Section S4.2.1 provides that, when tested separately from the upper torso anchorage, the pelvic anchorages must withstand a force of 5,000 pounds applied through the seat belt assembly. It is Ford's position that the 5,000 pound requirement of S4.2.1 was intended to be applicable to anchorages used with Type 2 assemblies having detachable shoulder belts, and that it was not intended for use with integral Type 2 assemblies. Although the NHTSA would agree that the most widely used Type 2 assembly at the time of the standard's adoption had a detachable shoulder belt, the agency does not agree that the 5,000 pound requirement should be limited to anchorages used with such belts. The 1974 model year will be the first in which integral Type 2 belts are installed in all passenger cars. We anticipate that a measurable percentage of persons riding in cars with the new belts will somehow avoid using the shoulder belt, thereby placing the lap belt under the same potential stress as any other lap belt when used by itself. In light of this possibility, and in consideration of the fact that keeping the pelvic anchorage force at the currently required level of 5,000 pounds will not impose additional manufacturing costs on manufacturers, we do not consider it advisable to grant the requested amendment at this time. The petition of Ford Motor Company for an amendment of S4.2.1 of Motor Vehicle Safety Standard No. 210 and for a complementary amendment to the test procedures of S5.1 of the standard is therefore denied. November 15, 1972 Douglas W. Toms Administrator National Highway Traffic Safety Administration Re: Petition for Amendment of Federal Motor Vehicle Safety Standard No. 210 - Seat Belt Assembly Anchorages Ford Motor Company, with offices at The American Road, Dearborn, Michigan 48121, as a domestic manufacturer of motor vehicles, hereby submits this Petition for Amendment of Federal Motor Vehicle Safety Standard No. 210 - Seat Belt Assembly Anchorages (hereinafter "the Standard"). This Petition is filed pursuant to Section 553.31 of the procedural rules of the National Highway Traffic Safety Administration. The purpose of this Petition is to request an amendment to S4.2.1 and S5.1 of the Standard that would eliminate the requirement of applying a 5000-pound force to the anchorages of the pelvic portion of a Type 2 seat belt assembly with a non-detachable upper torso portion. Sections S4.2.2 and S5.2 of the Standard adequately cover the anchorage loading for such a Type 2 seat belt assembly. This 5000-pound test criteria was developed originally for seat belt restraint systems that were independent of upper torso restraints and is still applicable to such systems as well as those that include a detachable upper torso belt system. Ford Motor Company plans to incorporate non-detachable upper torso straps as required by S4.1.2.3 of Federal Motor Vehicle Safety Standard 208 in its 1974 model vehicles. The present requirements of Federal Motor Vehicle Safety Standard 210 cause the restraint system to be dismantled before it can be tested, resulting in redundant and unnecssary tests and, therefore, are not practicable for this type of restraint system. Ford test and development programs for these vehicles are now at that point where prototype bodies incorporating 1974 restraint system component designs are available for tests according to Federal Motor Vehicle Safety Standard 210 demonstration procedures to determine that design levels are appropriate for production tooling. We urge your prompt attention to this matter to assure that our current product programs are not affected. Respectfully submitted, J. C. Eckhold Director, Automotive Safety Office |
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ID: nht73-6.2OpenDATE: 03/01/73 FROM: AUTHOR UNAVAILABLE; L. R. Schneider; NHTSA TO: Michigan Law Review COPYEE: MR. VINSON TITLE: FMVSS INTERPRETATION TEXT: This is in response to your undated letter to the National Highway Safety Bureau (since December 31, 1970, the National Highway Traffic Safety Administration) concerning Federal motor vehicle safety standards intended to protect the pedestrian and cyclist. You ask when Standard No. 211 Wheel Nuts, Wheel Discs and Hub caps was proposed and enacted. This standard was one of the Initial Federal standards proposed late in 1966 and issued in late January 1967 effective January 1, 1968, as to original and replacement equipment. This date is almost four months earlier than the date of the accident in Passwaters v. General Motors Corp., 454 F. 2d 1270 (1972) and thus there is no connection between the two. Standard No. 211 derives from a Swedish standard on vehicle exterior protrusions. Eventually we hope to have a definitive standard on exterior protrusions (incorporating Standard No. 211) intended to prevent serious injury to a pedestrian during the initial impact with the vehicle and to control his trajectory to reduce the severity of secondary impacts. The rule would specify impact force distribution and response requirements for exterior vehicle surfaces. Our initial rulemaking effort in this area was the issuance of an advance notice of proposed rulemaking establishing Docket No. 2-5, published October 14, 1967, (32 F.R. 14278) asking for general comments on size, shape, location, and sharpness of vehicle corners and edges. At the present time, proposals for research to establish threshold-of-injury data and to investigate techniques for reducing injury are being developed. On the basis of this data we will propose a standard on pedestrian protection. Under our current plans, the final standard would be issued late in 1975 with an effective date of September 1, 1990. We also plan to issue a standard on motorcycle rider protection systems around February 1, 1974, with an effective date of January 1, 1975. The agency's standard on motorcycle headgear, under current plans, will be issued around June 1, 1973, with an effective date of September 1, 1974. |
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ID: nht73-6.21OpenDATE: 02/15/73 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Nissan Motor Co., Ltd. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of January 4, 1973, concerning your continuing uncertainties about the intent of sections S4.3.1.1 and S4.3.1.3 of Standard 210. In your figure 1, assuming the seat is not adjustable, the contact points would be (b) in the first drawing and (c) in the second. However, a rigid attachment of the length shown in the second drawing would appear to violate the intent of S4.3.1.1 that the angle formed by the webbing in passing from the hardware to the seating reference point should be a forward angle. In your figure 2, if the bracket can be rotated so that an extension of its centerline would pass through the seating reference point, we would consider point (p) to be the nearest contact point for purposes of S4.3.1.1 and S4.3.1.3. With respect to the proposed used of a flexible wire, as shown in figure 3, the ability of the wire to move with reasonable freedom removes it from the category of rigid hardware. We would consider the points shown as (c) and (f) to be the appropriate contact points for purposes of S4.3.1.1 and S4.3.1.3. January 4, 1973 Lawrence Schneider National Highway Traffic Safety Administration Although we have received and appreciated your interpretation of MVSS 210, S4.3.1.1, and S4.3.1.3, Seat Belt Anchorages, this matter remains rather vague to us. Please permit us to restate the situations in question. We would like to use the seat belt system in which the buckle is attached to the floor panel (tunnel) or seat structure by a rigid bracket as indicated in the enclosed Figure 1. In this situation, please advise us of the correct nearest contact point and angle in each of the attached drawings. If the rigid bracket with buckle is able to rotate about point "P", as shown in Figure 2, please advise us where we should consider the nearest contact point and angle. We are also considering using another type of seat belt system, as shown in Figure 3, in which the buckle is attached to the floor panel through the flexible wire. Again, please indicate the exact nearest contact point and angle. Thank you for your kind assistance. Tatsuo Kato Engineering Representative Liaison Office in USA Enclosures The nearest contact point: (A) or (B)? The angle: 20 degree SEATING REFERENCE POINT
WEBBING
HORIZONTAL LINE
TONGUE
BUCKLE
RIGID BRACKET FIXED TO FLOOR PANEL OR SEAT STRUCTURE
SEATING REFERENCE POINT
THE NEAREST CONTACT POINT: (C), (D) or The angle: 20 degree [Graphics Omitted]
FIGURE 1
RIGID BRACKET
POINT "P"
[Graphics omitted]
FIGURE 3
The nearest contact point: (A), (B) or (C)? The angle: 20 degree SEATING REFERENCE POINT
BUCKLE
FLEXIBLE STEEL WIRE
[Graphs Omitted]
BUCKLE
SEATING REFERENCE POINT The nearest contact point: (D), (E), or (F)? The angle: 20 degree <ODY> |
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ID: nht73-6.22OpenDATE: October 26, 1973 FROM: Richard B. Dyson -- Assistant Chief Counsel, NHTSA TO: Brian Gill -- Assistant Manager, Safety & Environmental Activities, American Honda Motor Company TITLE: None ATTACHMT: Attached to letter dated 12-24-90 to Stanley S. Zinner from Paul Jackson Rice (A37; Std. 123); Also attached to letter dated 12-4-90 to Paul Jackson Rice from Stanley S. Zinner (OCC 5479); Also attached to letter dated 2-16-82 to Brian Gill from Frank Berndt (Std. 123) TEXT: This is in reply to your letter of 0ctober 9, 1973, to Mr. Vinson of this office asking whether S5.2.5 of Standard No. 123 requires footrests to fold automatically when not in use. The standard does not require automatic folding. S5.2.5 states only the direction in which footrests shall retract, so that if they are inadvertently left down when not in use they will fold rearward and upward should they hit an obstacle while the motorcycle is travelling forward. |
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ID: nht73-6.23OpenDATE: December 10, 1973 FROM: Richard B. Dyson -- Assistant Chief Counsel, NHTSA TO: Robert R. Aronson -- President, Electric Fuel Propulsion Corp. TITLE: None ATTACHMT: Attached to letter dated 11-26-73 from Robert R. Aronson to Lawrence Schneider (Chief Counsel, NHTSA) TEXT: This is in reply to your letter of November 26, 1973, inquiring about the applicability of Standard No. 301 to your vehicles' gasoline-powered water heaters. Standard No. 301 was promulgated in order to reduce the incidence of deaths and injuries resulting from fuel-related fires. The standard seeks to accomplish this end by specifying performance requirements which must be met by a motor vehicle's fuel system. Although the fuel systems primarily regulated by the standard are those which propel the vehicle, nothing in the standard limits its application to those systems. A fuel system which powers another aspect of the vehicle's operation, such as the gasoline- powered Stewart Warner Water Heater, is susceptible to the same hazards as the more commonly encountered fuel system, and thus they must be regulated in the same manner in order to fulfill the purposes of Standard No. 301. In summary, the 2-quart fuel tank to which you refer is subject to the requirements of Standard No. 301. |
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ID: nht73-6.24OpenDATE: November 26, 1973 FROM: Robert R. Aronson -- President, Electric Fuel Propulsion Corp. TO: Lawrence Schneider -- Chief Counsel, NHTSA TITLE: None ATTACHMT: Attached to letter dated 12/10/73 from Richard B. Dyson to Robert R. Aronson TEXT: In reference to FMVSS 301, our electric cars are equipped with a 2-quart gasoline tank which powers a Stewart Warner Water Heater for heating and defrosting cars. The location of the gas tank and heater is in the rear of the car. Please let us know if Standard 301 applies to this gas tank. |
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ID: nht73-6.3OpenDATE: 11/14/73 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Rolls-Royce Motors Limited TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of October 16, 1973, requesting a clarification of S7.2 of Federal Motor Vehicle Safety Standard No. 301 (9-1-75) (Docket No. 70-20; Notice 2). As you are aware, a proposed amendment to Federal Motor Vehicle Safety Standard No. 301 (9-1-75) was published on August 20, 1973 with an anticipated September 1975 effective date (Docket No. 73-20; Notice 1). In the event that the proposed amendment of loading conditions is adopted, the present passenger car requirement, that the vehicle be at its GVWR during testing, will be superseded by the requirement that the passenger car be loaded "to its unloaded vehicle weight plus its rated cargo and luggage capacity weight, secured in the luggage area, plus the weight of the necessary dummies." Under these specifications, rear seat occupant weight will not be a factor of the test load condition unless a specific test requirement calls for dummies to be placed in designated rear seating positions. The proposed amendment would also make it unnecessary to firmly fix the dummies to the vehicle as is presently the case under S7.2. We have also noted your views on luggage capacity weight and are placing your letter in Docket No. 73-20 as a comment to be considered. If you require any further clarification, please do not hesitate to let us know. OCTOBER 16, 1973 The Administrator National Highway Traffic Safety Administration, Dear Sir, 49 CFR, PART 571 Docket No. 70-20; Notice 2 Standard No. 301 - Fuel System Integrity Rolls-Royce Motors Limited seeks clarification on the meaning of S 7.2 as published in the Federal Register 38 FR 22397, dated August 20, 1973. S 7.1 requires the vehicle under test to be loaded to its GVWR and S 7.2 requires weight in excess of the unloaded vehicle weight to be firmly fixed to the vehicle so that it absorbs no significant portion of the vehicle's Kinetic energy. It seems to us that the only way in which the added weight can absorb the vehicle's Kinetic energy is by actual deformation of the weight itself. Thus, it would be unacceptable to apply added weight which would reinforce the front structure of the vehicle. This would be entirely logical with a front engined vehicle, but would pose serious problems with a rear engined vehicle in which the luggage compartment was at the front of the vehicle. Would there not be practical difficulties in achieving the correct weight distribution, and is it not reasonable for the designer to intend the luggage in these circumstances to absorb some of the vehicle's Kinetic energy, particularly that due to its share of the total mass, when the vehicle is loaded to its GVWR? 2 Rolls-Royce Motors Limited does not make vehicles with luggage stowage capacity at the front, so that particular problem is of no immediate concern to us at this moment. We would, however, be very concerned if the conditions of S 7.2 were to be applied to any future rear barrier crash test, and hence our interest in seeking clarification. Our own suggestion would be to omit the luggage weight from the vehicle test weight, while a specification is drawn up for inexpensive test pieces representing more closely the density and crush characteristics of real life passenger luggage. Such test pieces would be stowed in the luggage compartment but not secured to the vehicle structure, again representing more closely real life conditions. Docket No. 73-20, Notice 1. proposes an amendment to Standard No. 301, effective September 1975, which would permit the installation of dummies in the front outboard seating positions. It is not clear to us how the weight of the rear seat occupants is to be provided when ballasting the vehicle up to its GVWR. We sincerely hope that S 7.2 of Docket No. 70-20, Notice 2, will not be interpreted to mean that the added weight due to rear seat passengers must be rigidly attached to the vehicle. For obvious economic reasons, which are of vital importance to the low volume manufacturer, we would want to combine testing against Standard No. 301 with testing against other Standards, such as No. 208, and S 5.1 of Standard No. 208 requires anthropomorphic test devices to be installed at each designated seating position. The restraint systems used for these dummies to demonstrate compliance with Standard No. 208 could not be described as rigid. We should, therefore, be most grateful if you could clarify the requirements of S 7.2 of Standard No. 301 regarding the means to be used for installing additional weight to bring the test vehicle up to its GVWR. Yours faithfully, J. B. H. Knight Chief Development and Car Safety Engineer Copies to: Trevor Williams Rolls-Royce Motors Inc. New Jersey. K. B. Barnes The Society of Motor Manufacturers & Traders Ltd. London. |
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ID: nht73-6.4OpenDATE: 11/12/73 FROM: AUTHOR UNAVAILABLE; Robert L. Carter; NHTSA TO: Honorable John B. Conlan, U.S. House of Representatives COPYEE: SEC. REP. DUNN; DR. KAYE; J. L. LEYSATH; MR. VINSON TITLE: FMVSS INTERPRETATION TEXT: This will supplement the Bureau of Motor Carrier Safety's reply of October 30, 1973, to your letter of September 21, 1973, to the Interstate Commerce Commission, concerning Mr. William H. Arendell's automatic light-blinking device for truck signaling. The Bureau has referred your letter to us for further reply. Enclosed for your constituent's information is a copy of Federal Motor Vehicle Safety Standard No. 108, entitled, "Lamps, Reflective Devices and Associated Equipment." The effect of paragraph S4.6 of the standard is to prohibit the use of automatic flashing clearance lamps for signaling purposes on vehicles manufactured on or after January 1, 1972. The term "flash" is defined (paragraph S3) as "a cycle of activation and deactivation of a lamp by automatic means continuing until stopped either automatically or manually." It appears that the device described in your constituent's letter falls within the prohibition of Standard No. 108, and could not be used as original equipment on vehicles. Its use as an aftermarket device would be subject to regulation by the individual States. I trust the above information will be of interest to Mr. Arendell. 2 ENCLS. CONSTITUENT'S LETTER STD. NO. 108 |
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ID: nht73-6.5OpenDATE: 11/14/73 FROM: E. T. DRIVER -- NHTSA; SIGNATURE BY CHARLES A. BAKER TO: Browning-Ferris Industries, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of October 26 to Mr. J. E. Leysath of this office concerning marker and signal lights on your Mack trucks. Federal Motor Vehicle Safety Standard No. 108 requires that front clearance and identification lamps be located as close as practicable to the top of the vehicle. Mounting these lamps on the top of the vehicles described in your letter does not appear to be practicable because of possible damage to the lamps. If mounting the lamps on the front vertical surface near the top is, in your determination, "as close to the top as practicable," then you have met the requirements of Standard No. 108. Mounting an additional side marker lamp (which you have identified as a corner clearance lamp) on each side of the cab, near the front and top of the cab, would not be prohibited by Standard No. 108. Turn signal lamps and hazard warning signal lamps mounted on the rear of the vehicle may be either red or amber. The color of these lamps was addressed in a Notice of Proposed Rule Making published in the Federal Register on October 25, 1972, (Docket 69-19; Notice 3). It was proposed that amber be eliminated as an optional color for these lamps, but no final decision has been made. |
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.