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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



Displaying 13901 - 13910 of 16514
Interpretations Date
 search results table

ID: nht93-7.28

Open

DATE: October 19, 1993

FROM: Donald W. Vierimaa -- Vice President-Engineering, Truck Trailer Manufacturers Association

TO: John Womack -- Acting Chief Counsel, NHTSA

COPYEE: Tank Conference Engineering Committee; TTMA Engineering Committee; Retroreflective and Reflector Devices Associates

TITLE: Conspicuity

ATTACHMT: Attached to letter dated 11/22/93 from John Womack to Donald W. Vierimaa (A41; Std. 108)

TEXT:

Often a new tank trailer will be sold to a customer who will contract with another party to have a lining installed in the tank. High heat is used to apply this lining. After the lining is installed, the tank trailer is painted. After the tank is painted, conspicuity treatment is applied. The high heat used in the installation of the lining precludes the application of paint and retroreflective sheeting to the tank before the lining is installed.

In addition, non-tank trailers may be sold without conspicuity treatment when the owner wishes to contract the application of special paint and logo schemes.

49 CFR 568.3 defines an incomplete vehicle as one "that requires further manufacturing operations, other than the addition of readily attachable components, such as mirrors or tire and rim assemblies, or minor finishing operations such as painting, to become a completed vehicle."

Is a trailer manufactured after December 1, 1993 and sold without the conspicuity treatment required in FMVSS 108 an incomplete vehicle? If you consider such a trailer to be a completed vehicle, does NHTSA require that the manufacturer furnish the owner with (1) retroreflective sheeting or reflex reflectors complying with FMVSS 108, (2) instructions as to where on the trailer the conspicuity treatment should be installed, and/or (3) instructions on preparing the surface for the application of the conspicuity treatment? Should conspicuity treatment installed by the owner be deemed to be not in compliance with S5.7 of FMVSS 108, is the owner solely responsible for the violation and for bringing the trailer into compliance?

If NHTSA determines that the installation of conspicuity treatment is a readily attachable component and therefore a complete vehicle, can the manufacturer certify that "This vehicle conforms to all applicable Federal motor vehicle safety standards in effect on the date of manufacture shown above" if the trailer is not furnished with the conspicuity treatment required by FMVSS 108?

ID: nht93-7.29

Open

DATE: October 20, 1993

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Richard Glover -- Evenflo Juvenile Furniture Co.

TITLE: None

ATTACHMT: Attached to letter dated 6/3/93 from Richard Glover to Deirdre Fujita (OCC-8744)

TEXT:

This responds to your letter and telephone calls about the child seat registration form you are considering. The form is required by S5.8 of Standard 213, "Child Restraint Systems," and is depicted in figures 9a and 9b of the standard.

You ask whether S5.8(c) permits you to place certain additional information in the shaded area on the form. The information is a bar code that you said on the telephone contains information on "date of manufacture, shift, location and serial number for the product that the card represents." You explain that the bar code is desired because it can be automatically scanned, which would avoid possible "mis-keying" of the information into the data record. Further, you state that the bar code has to be surrounded by a slightly larger unshaded "quiet zone" to enable the scanner to record the bar code information. You, are concerned whether NHTSA would conclude that the quiet zone renders a part of the shaded area unshaded.

It is our opinion that a bar code that contains the information you described is permitted in the shaded area (the area outside of the space, for the consumer to fill in). S5.8(c) of Standard 213 specifies the information that must be provided on the form and states the following:

No other information shall appear on the postcard, except identifying information that distinguishes a particular child restraint system from other systems of that model name or number may be preprinted in the shaded area of the postcard, as shown in figure 9a.

The bar code, printed in the shaded area, is permitted by S5.8(c). The information provided by the bar code distinguishes a particular child seat from another of the same model name or number. We consider the quiet zone as part of the bar code since it is needed for the bar code to be reliably read. The quiet zone therefore need not be shaded, since the printed bar code (or any other identifying information permitted by S5.8(c)) itself is not.

Please note that, while the bar code is permitted, the information on the model name or number and date of manufacture must still be in English under S5.8(c). This information must be in English so that a consumer can see that this information has been provided and that only minimal effort is needed to fill out the registration form.

We also wish to note another feature of the form you faxed. Your form has the words "please print" after the instructions to the consumer "just fill in your name and address." "Please print" is not on the form depicted in figures 9a and 9b of Standard 213. In an earlier letter, NHTSA decided

that a minor variation in the wording of a warning expressly specified by Standard 213 was permitted when the change clarified the warning and did not make any substantive change to the warning's meaning. (Letter to Mr. McGuigan, December 18, 1980.) Similarly, "please print" is a minor variation to the wording of the instructions that clarifies the instructions and does not substantively change them. Thus, it is permitted.

I hope this information is helpful. Please call Ms. Fujita at (202) 366-2992 if you have further questions.

ID: nht93-7.3

Open

DATE: October 1, 1993

FROM: John Womack -- Acting Chief Counsel, NHTSA; Stephen P. Wood

TO: Docket Section (Redbook, Standard No. 208)

TITLE: Interpretation of Standard No. 208

TEXT:

At the request of the Office of Vehicle Safety Compliance (OVSC), this provides, for the public docket, an interpretation of the requirements of S7.1.1 and S7.1.1.1 of Standard No. 208, Occupant Crash Protection. OVSC asked us to address whether these sections require safety belts at the driver's position of vans to fit around a 95th percentile male dummy when the driver's seat is in the full forward position. As discussed below, the answer to that question is yes.

The general structure of S7.1.1 through S7.1.1.2 is that S7.1.1 sets forth requirements for seat belt assemblies that apply except as those requirements are modified in S7.1.1.1 and S7.1.1.2. S7.1.1.1 modifies S7.1.1 with respect to the range of people that must be fit, but not with respect to the range of seating positions in which that fit must be provided. S7.1.1 provides:

S7.1.1 Except as specified in S7.1.1.1 and S7.1.1.2, the lap belt of any seat belt assembly furnished in accordance with S4.1.2 shall adjust by means of any emergency-locking or automatic-locking retractor that conforms to S571.209 to fit persons whose dimensions range from those of a 50th percentile 6-year-old child to those of a 95th percentile adult male and the upper torso restraint shall adjust by means of an emergency-locking retractor or a manual adjusting device that conforms to S571.209 to fit persons whose dimensions range from those of a 5th percentile adult female to those of a 95th percentile adult male, with the seat in ANY POSITION, the seat back in the manufacturer's nominal design riding position, and any adjustable anchorages adjusted to the manufacturer's nominal design position for a 50th percentile adult male occupant. . . . (Emphasis added.)

Thus, except as modified in S7.1.1.1 and S7.1.1.2, the lap belt and upper torso restraint of any seat belt assembly must meet all the requirements of S7.1.1. More specifically, the lap belt must adjust to fit persons whose dimensions range from those of a 50th percentile 6-year old child to those of a 95th percentile adult male, and the upper torso restraint must adjust to fit persons whose dimensions range from those of a 5th percentile adult female to a 95th percentile adult male, with the seat in any position.

S7.1.1.1 makes a limited modification to S7.1.1's requirements for seat belt assemblies at the driver's seating position; S7.1.1.2 is not relevant to that seating position. Section S7.1.1.1 provides:

S7.1.1.1 A seat belt assembly installed at the driver's seating position shall adjust to fit persons whose dimensions range from those of a 5th-percentile adult female to those of a 95th-percentile adult male.

S7.1.1.1 is significant in what it addresses and what it does not address. It does address the lap belt for the driver's seating position and as to that belt, the range of occupant sizes which must be fit. For the driver's seating position, the general requirement that the lap belt of any seat belt assembly must adjust to fit persons whose dimensions range from those of a 50th percentile 6-year-old to those of a 95th percentile male is modified by S7.1.1.1 to apply to persons whose dimensions range from those of a 5th-percentile adult female to those of a 95th percentile adult male. However, S7.1.1.1 does not address the range of seating positions in which seat belt fit must be provided and thus makes no change in S7.1.1 with respect to that range.

Therefore, S7.1.1 and S7.1.1.1 together require, for seat belt assemblies at the driver seating position, that the lap belt and upper torso restraint must adjust to fit persons whose dimensions range from those of a 5th percentile adult female to a 95th percentile adult male, with the seat in any position.

The use of the term "any" merits special emphasis. With respect to the requirement that safety belts must fit the specified range of occupant sizes with the seat in "any position," the term "any," when used in connection with a set of items, is specifically defined at 49 CFR 571.4 as meaning the totality of that set of items, any one of which may be selected by the Administration for testing. Therefore, safety belts at the driver's position of vans must fit a 95th percentile male dummy with the seat in all possible positions, including the full forward position.

ID: nht93-7.30

Open

DATE: October 20, 1993

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: James Z. Peepas -- Selecto-Flash, Inc.

TITLE: None

ATTACHMT: Attached to letter dated 7/26/93 from James Womack from James Z. Peepas (A41; Std. 108) and letter dated 7/9/93 from James Z. Peepas to Taylor Vinson (OCC-8871)

TEXT:

In a recent letter of interpretation on the trailer conspicuity requirements of Standard No. 108, which are effective December 1, 1993, we informed you that "()f you determine that this configuration meets S5.7.1.4.2(a) without the container load in place, there would be no need to increase the amount of retroreflective sheeting on the trailer behind the gooseneck." The word "without" is incorrect, and should be replaced with the word "with", in accordance with the requirement of S5.7.1.4.2(a) that conspicuity treatment not be obscured by trailer cargo. We are sorry for any inconvenience that this error may have caused you.

Our letter also informed you that we were considering a petition for reconsideration of the mounting height requirements for the conspicuity treatment. On October 6, 1993, the agency published its response to this petition, modifying the mounting height requirement to a range between 15 and 60 inches (375 to 1525 mm). I enclose a copy of the amendment for your information.

ID: nht93-7.31

Open

DATE: October 20, 1993

FROM: Jerome Cysewski -- Ideal Mfg., Inc.

TO: Office of the Chief Counsel -- NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 1/24/94 from John Womack to Jerome Cysewski (A42; VSA 102)

TEXT:

I would like to have your interpretation of the following equipment regarding NHTSA statutes, regulation and standards:

The cement silo has tandem axles, weighs 13,600 pounds, the silo is mounted on its own trailer operated by electric brakes. This piece of equipment is pulled by a one ton truck with hydraulic brakes.

The aggregate batch plant has a single axle, weighs 6400 pounds, the batch plant is mounted on its own trailer operated by electric brakes. This piece of equipment is pulled by a one ton truck with hydraulic brakes.

Both pieces of equipment are mobile but are designed to be towed with vehicles for off-the-road set and positioning, this equipment is for a one man operation.

Please return my request to the above address. Thank you for your attention in this matter.

ID: nht93-7.32

Open

DATE: October 21, 1993

FROM: James "Bubba" Schaub -- Midas Muffler and Brake

TO: John Womack -- Acting Chief Council, NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 5/8/94 from John Womack to James Schaub (A42; Std. 105; Part 570)

TEXT:

First allow me to introduce myself. My name is James "Bubba" Schaub. I manage a Midas Muffler and Brake Shop in Slidell, Louisiana, located at 180 Gause Blvd., and have for 9 years now. My concern is in the area of ethical and sound business practice. I'm taught by Midas to replace brake rotors and/or brake drums when they exceed the minimum thickness (on disc rotors) or maximum diameter (on drums), published by Original Equipment Manufacturers. My questions are as follows:

1. Please interpret F.M.V.S.S. 105 HYDRAULIC BRAKE SYSTEMS.

2. Is there any basis for fraud in following this policy? (Of disc rotor and/or drum replacement when out of manf. safety tolerances).

Please understand that my concern lies only with doing the right thing - the safe way, for our costumers. Let it be known that the local auto dealership service dept.'s are not following their own recommendations, for safety in this matter, which causes my costumers to believe that we (Midas) are fraudulently selling and installing parts on their vehicles when they're not needed. But, if I can present an established standard to our (Midas) costumers, I can prevent them from feeling they've been taken advantage of.

ID: nht93-7.33

Open

DATE: October 21, 1993

FROM: Schaub, James (Bubba) -- Midas Muffler And Brake Shop

TO: Womack, John -- Acting Chief Council, NHTSA

TITLE: NONE

ATTACHMT: Attached To 5/18/94 Letter From John Womack To James Schaub (A42; PART 570)

TEXT: First allow me to introduce myself. My name is James "Bubba" Schaub. I manage a Midas Muffler and Brake Shop in Slidell, Louisiana, located at 180 Gause Blvd., and have for 9 years now. My concern is in the area of ethical and sound business practice. I'm taught by Midas to replace Brake rotors and/or Brake Drums when they exceed the minimum thickness (on disc rotors) or maximum Diameter (on Drums), published by original Equipment manufacturers. My questions are as follows -

1. Please [ILLEGIBLE WORD] F.M.V.S.S. 105 HYDRAULIC BRAKE SYSTEMS

2. Is there any basis for [ILLEGIBLE WORD] in following this policy? (of disc rotor and/or Drum replacement when out of manf. safety [ILLEGIBLE WORD]).

Please understand that my concern lier only with doing the right thing - the safe way, for our customer. Let it be known that the [ILLEGIBLE WORDS] are not following their own recommendations, for safety in this matter, which causes my customers to believe that we (midas) are fraudulently, selling and installing parts on thier vehicles when [ILLEGIBLE WORD] not needed. But, if I can present on established standard to our (midas) Customers, I can prevent them from feeling they've been taken advantage of.

(ARTICLE FROM UNDERCAR DIGEST IS OMITTED.)

ID: nht93-7.34

Open

DATE: October 22, 1993

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: John P. Gach -- Marketing Coordinator, North American Lighting, Inc.

TITLE: None

ATTACHMT: Attached to letter dated 9/1/93 from John P. Gach to Richard Van Iderstein (OCC-9084)

TEXT:

We are replying to your letter of September 1, 1993, to Richard Van Iderstine of this agency with respect to the "Blu-Lite." You would like our views on this product "in both OEM and aftermarket applications."

The advertising circular which you enclosed shows Blu-Lite to be a three-compartment stop lamp that is mounted in the center of the parcel shelf adjacent to the rear window. The center compartment contains a blue light "that comes on immediately with heavy brake pressure and flashes quickly and independently from your regular brake lights." The center blue light compartment is flanked by compartments that contain a "red stop light."

It is clear that Blu-Light is intended as a substitute for the center highmounted stop lamp that Federal Motor Vehicle Safety Standard No. 108 has required to be installed as original equipment on passenger cars manufactured on and after September 1, 1985, (and light trucks and vans since September 1, 1993). Blu-Light does not meet the original equipment specifications of Standard No. 108 because, among other things, it is not a single red lamp mounted on the vertical centerline of the vehicle. Therefore, Blu-Light is impermissible under Federal law as original motor vehicle lighting equipment.

With respect to aftermarket applications, the National Traffic and Motor Vehicle Safety Act prohibits any manufacturer, distributor, dealer, or motor vehicle repair business from "knowingly rendering inoperative in whole or in part" any equipment installed in accordance with a Federal motor vehicle safety standard. Removal of the original equipment center lamp and replacement with Blu-Light would be a "rendering inoperative" as we interpret that term, and, hence, a prohibited act. However, the prohibition does not extend to persons outside the four named categories, such as the vehicle owner, and installation of Blu-Light by persons not named in the prohibition would not violate any Federal requirement. But the legality of the use of Blu-Light is determinable under the laws of each State in which the device is operated. As you note, many States reserve the color blue for lamps used to indicate emergencies. If you are interested in pursuing this question further, the American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203, can advise you whether any State allows the use of blue lamps for other than emergency use.

Further, there is no violation of Federal law involved in installing Blu- Lite on vehicles that were not required by Standard No. 108 to be originally equipped with one, i.e., cars manufactured before September 1, 1985, and

other vehicles manufactured before September 1 of this year. In this instance, too, legality of use is determinable under State law.

I hope that this answers your questions.

ID: nht93-7.35

Open

DATE: October 22, 1993

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Milford R. Bennett -- Head, Safety Affairs and Operations, NAO Engineering, Safety Center, General Motors Corporation

TITLE: None

ATTACHMT: Attached to letter dated 10/7/93 from Milford R. Bennett (Signature by Richard F. Humphrey) to H. M. Smolkin (OCC-9189)

TEXT:

This is in reply to your letter of October 7, 1993, to Howard Smolkin concerning information labels for vehicles covered by NHTSA temporary exemptions (49 CFR Part 555).

Paragraph 555.9(b) requires that a windshield or side window label containing an advisory statement be affixed securely to each exempted vehicle. You have concluded that this label is intended to notify prospective purchasers that the vehicle has been exempted from compliance with certain Federal motor vehicle safety standards. Because General Motors (GM) does not intend to sell its recently exempted GMEV, it believes that it is not required to place the label on its vehicles.

Section 123(b) of the National Traffic and Motor Vehicle Safety Act (the Act) (15 U.S.C. 1410(b)) specifies that "(t)he Secretary may require that written notification of (an) exemption be delivered to the dealer and first purchaser for purposes other than the resale of such exempted motor vehicle in such manner as he deems appropriate." NHTSA chose to exercise this discretionary power through promulgating paragraph 555.9(b) requiring windshield and side window labels on exempted vehicles, commenting that "(t)he window label appears to be the most appropriate way of providing written notification of exemptions to dealers and first purchasers" (37 FR 25534).

We read in The New York Times on October 14, 1993, that GM will build 50 Impacts (presumably the exempted GMEVs) "and lend them for two to four weeks to 1,000 drivers around the country over the next two years, with the help of 14 utilities." If these cars are made available through GM's dealer network, then we believe that the label should nevertheless be provided even if the vehicle is not sold, and that it should remain affixed until the vehicle is first lent or leased through the dealer. Although subsequent users of the GMEV will not have access to the temporary label in order to evaluate the risk they assume by accepting temporary use of a nonconforming motor vehicle, the permanently affixed exemption certification label will furnish this information should they care to consult it.

ID: nht93-7.36

Open

DATE: October 22, 1993

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Richard A. Wennerberg -- Vice President, Marketing Services, American Gas Association

TITLE: None

ATTACHMT: Letter dated 8/19/93 from Richard A. Wennerberg to John Womack (OCC-9019)

TEXT:

This responds to your request for a letter explaining the status of Federal regulations applicable to compressed natural gas (CNG) containers for motor vehicles and CNG fueled motor vehicles. As you stated, representatives of the National Highway Traffic Safety Administration (NHTSA), an agency of the United States Department of Transportation, met with the American Gas Association (AGA) on August 16, 1993 to clarify your understanding of this agency's statutory authority with respect to the notice of proposed rulemaking for CNG fuel containers and vehicles using CNG as a fuel. (58 FR 5323, January 21, 1993) This letter, which you plan to forward to State officials interested in CNG fueled motor vehicles, summarizes this information.

By way of background information, NHTSA is authorized under the National Traffic and Motor Vehicle Safety Act (15 U.S.C. S1381 et seq.; Safety Act) to issue Federal motor vehicle safety standards that set performance requirements for new motor vehicles and items of motor vehicle equipment. The Research and Special Programs Administration (RSPA), another agency of the U.S. Department of Transportation, is authorized by Congress to issue standards for containers, including CNG containers, used to transport hazardous materials. RSPA does not have the statutory authority to issue a standard for CNG containers that are used to fuel a motor vehicle. Therefore, if the Federal government were to issue a standard applicable to the manufacture of CNG containers designed to fuel a motor vehicle, NHTSA is the only Federal agency authorized to do so.

At present, NHTSA has not issued any standard applicable to CNG containers, CNG fueled vehicles or any regulation dealing with the conversion of vehicles to be equipped with such containers. Therefore, until such time as a standard is issued, a manufacturer is not required to comply with any NHTSA or Department of Transportation safety standard related to CNG fuel systems.

Nevertheless, manufacturers of CNG containers and vehicles are subject to the requirements in sections 151-159 of the Safety Act concerning the recall and remedy of products with defects related to motor vehicle safety. In the event that NHTSA or the manufacturer of the container or vehicle determines that the product contains a safety-related defect, the manufacturer would be responsible for notifying purchasers of the defective equipment and remedying the problem free of charge.

In addition, NHTSA has certain restrictions on vehicle fuel system conversions, depending on who does the conversion and when the work is done.

I have enclosed a discussion that sets forth the implications under our present regulations of converting new and used gasoline-powered vehicles to use propane or other gas (such as CNG). That discussion addresses NHTSA's vehicle alterer requirements (49 CFR S567.7) which apply to work on new vehicles, and the Safety Act's "render inoperative" provision (S108(a)(2)(A)), which applies to work on new and used vehicles. Section 108(a)(2)(A) prohibits vehicle manufacturers, distributors, dealers and repair businesses from "knowingly rendering inoperative, in whole or in part, any device or element of design installed ... in compliance" with any FMVSS. If the agency were to ultimately decide to adopt the proposal, it would be necessary for NHTSA to revisit the "render inoperative" issues that relate to vehicle conversions. For example, if NHTSA were to issue a safety standard for CNG containers, all containers manufactured after the effective date of the standard would be required to comply with its requirements, whether they are placed on new vehicles or on new or used vehicles converted to CNG fuel.

In addition to these current regulatory provisions, as mentioned above, NHTSA issued a proposed rule for CNG containers and vehicles using CNG as a fuel. As we explained at the August 16, 1993 meeting, the agency is currently reviewing the comments to the proposal for CNG containers and vehicles using CNG as a fuel. We expect our next regulatory decision in early 1994. As we explained, the January 1993 notice was a proposal and does not necessarily reflect the precise requirements that will be contained in the final rule, assuming that a rule is issued.

If a Standard is issued, each manufacturer would be responsible for certifying that its products meet with the requirements of that standard. This is so because the "Safety Act" establishes a "self-certification" process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. NHTSA does not, however, approve or certify any vehicles or items of equipment. NHTSA also investigates safety-related defects in motor vehicles and items of motor vehicle equipment.

You should also be aware that the Federal Highway Administration (FHWA) of this Department has operational and equipment requirements for commercial vehicles used in interstate commerce. For information about possible FHWA requirements affecting your conversions, you can contact that agency's Chief Counsel's office at (202) 366-0650.

I hope you find this information helpful. If you have any other questions, please contact Marvin Shaw at this address or by phone at (202) 366-2992.

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.