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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 10631 - 10640 of 16510
Interpretations Date
 search results table

ID: nht95-1.61

ID: nht95-1.62

Open

TYPE: INTERPRETATION-NHTSA

DATE: February 13, 1995

FROM: Philip R. Recht -- Chief Counsel, NHTSA

TO: Scott E. Peters -- Director, Regulations & Compliance, U.S. Electricar

TITLE: None

ATTACHMT: ATTACHED TO 10/21/94 LETTER FROM SCOTT E. PETERS TO PHIL RECHT

TEXT: This responds to your letter to me in which you asked whether Federal Motor Vehicle Safety Standard (FMVSS) No. 110, Tire selection and rims (49 CFR 571.110), applies to your Electricar sedan.

You explained that your Electricar sedan (Electricar), a converted Geo Prizm, is being built under NHTSA Exemption No. 92-3 for low-emission vehicles. You stated that the Electricar's speed and endurance limitations are substantially below those of inte rnal combustion-powered vehicles. You further stated that it is your understanding that "the purpose of Standard No. 110, S4.4.2 (I assume you meant paragraph S4.2.2, since there is no S4.4.2 in the standard) is to ensure against tire failure due to pro longed operation at speeds in the range of 75 mph or higher." Thus, you interpret FMVSS No. 110 as not applying to the Electricar or other electric passenger cars "in which it is physically impossible to operate at high speeds for an extended duration." You asked this agency, therefore, to review paragraph S4.2.2 and provide you our opinion as to its applicability to your Electricar. As discussed below, the requirements of S4.2.2 are applicable to electric passenger cars.

By way of background information, the National Highway Traffic Safety Administration issues safety standards for motor vehicles and motor vehicle equipment. The agency does not provide approvals of motor vehicles or motor vehicle equipment. Instead, ma nufacturers are required to certify that their vehicles and equipment meet applicable safety standards.

Federal Motor Vehicle Safety Standard No. 110 specifies requirements for tire selection to prevent overloading. Section S2 of the standard provides that the standard applies to passenger cars. S4.2 of the standard specifies the following tire load limi ts:

S4.2.1 The vehicle maximum load on the tire shall not be greater than the applicable maximum load rating as marked on the sidewall of the tire.

S4.2.2 The vehicle normal load on the tire shall not be greater than the test load used in the high speed performance test specified in S5.5 of section 571.109 of that tire.

The test load used in the high speed performance test specified in S5.5 of Standard No. 109 is 88 percent of the tire's maximum load rating as marked on the tire sidewall.

With respect to your question whether S4.2.2 applies to electric passenger cars, the answer is yes. That section applies on its face to all passenger cars, and does not include an exception for electric passenger cars.

Your understanding that the purpose of S4.2.2 is limited to ensuring against tire failure due to prolonged operation at speeds in the range of 75 mph or higher is incorrect. The reference in that requirement to Standard No. 109's high speed performance test is for the sole purpose of specifying a load and not to indicate that the requirement is limited to high speed operation.

As indicated above, Standard No. 110 seeks to ensure that tires are not overloaded. One way Standard No. 110 does this is by requiring in S4.2.1 that the vehicle maximum load on the tire not exceed the maximum load rating of the tire. Another way Stand ard No. 110 does this is by limiting the vehicle normal load on the tire, so that the tire will have some reserve load carrying capacity available to handle safely cargo and other kinds of added loading the car may experience. S4.2.2 does this by limiti ng the normal load on a tire to 88 percent of the tire's maximum load rating, which ensures that 12 percent of the tire's load rating will be available to bear cargo and other added loads.

I hope this information is helpful to you. Should you have any further questions or need additional information, please feel free to contact Walter Myers of my staff at this address or at (202) 366-2992.

ID: nht95-1.63

Open

TYPE: INTERPRETATION-NHTSA

DATE: February 13, 1995

FROM: Philip R. Recht -- Chief Counsel, NHTSA

TO: G. Brandt Taylor -- President, Day-Night Mirrors, Inc.

TITLE: None

ATTACHMT: ATTACHED TO 12/6/94 LETTER FROM G. BRANDT TAYLOR TO PHILIP R. RECHT (OCC 10553)

TEXT: This responds to your letter asking about the requirements applicable to multiple reflectance mirrors in Federal Motor Vehicle Safety Standard (FMVSS) No. 111, Rear View Mirrors. You stated that your mirror can change its reflectivity either by mechanica lly rotating a shaft or by actuating an electrical motor.

By way of background information, the National Highway Traffic Safety Administration (NHTSA) has the authority to issue safety standards for new motor vehicles and new items of motor vehicle equipment. NHTSA does not, however, approve or certify any veh icles or items of equipment. Instead, each manufacturer is responsible for "self-certifying" that its products meet all applicable safety standards. The agency periodically tests vehicles and items of equipment for compliance with the standards.

FMVSS No. 111 specifies requirements for the performance and location of rearview mirrors. Section S11, which specifies requirements for mirror construction, provides in relevant part that

All single reflectance mirrors shall have an average reflectance of at least 35 percent. If a mirror is capable of multiple reflectance levels, the minimum reflectance level in the day mode shall be at least 35 percent and the minimum reflectance level in the night mode shall be at least 4 percent. A multiple reflectance mirror shall either be equipped with a means for the driver to adjust the mirror to a reflectance level of at least 35 percent in the event of electrical failure, or achieve such refl ectance automatically in the event of electrical failure.

You asked several questions about the requirement for adjusting the mirror in the event of electrical failure. You first asked if a manual override knob could be removable. You then asked whether a removable manual override could be supplied by the car manufacturer along with the car keys or with the owner's manual for insertion into the mirror and use only in the event of an electrical failure. You also asked about whether "west coast" mirrors and mirrors on trailer trucks could have a removable man ual override.

The answer to each of your questions is that a removable manual override knob would not be permitted. In the preamble to the final rule amending the mirror construction requirements in FMVSS No. 111, NHTSA stated that the agency's goal is to assure that multiple reflectance mirrors are capable of providing adequate images at all times during the vehicle's operation, including electrical failure situations where the mirror is unpowered. (see 56 FR 58513, November 20, 1991)

The manual override knob you discuss would serve as the means for the driver to adjust the mirror's reflectance level. However, a removable manual override knob would not always serve this purpose, since it would not necessarily always be with the mirro r. We are concerned that a removable override device may become lost or otherwise not available when a mirror's reflectance needs to be adjusted. Accordingly, since the agency's goal of providing adequate images at all times during the vehicle's operat ion would only be achieved by requiring this device to be permanent, a removable override would not be permitted.

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

ID: nht95-1.64

Open

TYPE: INTERPRETATION-NHTSA

DATE: February 13, 1995

FROM: Philip R. Recht -- Chief Counsel, NHTSA

TO: Ken Liebscher -- President/Director, Electric Car Company

TITLE: None

ATTACHMT: ATTACHED TO 1/16/95 LETTER FROM KEN LIEBSCHER TO NHTSA ADMINISTRATOR

TEXT: We have reviewed your application of January 16, 1995, for temporary exemption of the M1-6 electric passenger car from six Federal Motor Vehicle Safety Standards, on the basis that compliance would cause Electric Car Company ("Electric Car") substantial economic hardship. We need some additional information before we are able to consider the application further.

A hardship applicant must provide corporate balance sheets and income statements for the three fiscal years preceding the filing of the application. You have filed statements for E.T.C. Industries and only for two years, those ending December 31, 1992, and December 31, 1993. This is acceptable since your submission indicates that E.T.C. Industries (apparently a Canadian corporation) is the parent of Electric Car (a Nevada corporation incorporated on November 24, 1993), and that "the consolidated finan cial statements [that you have provided us] include the accounts of Electric Car . . . ." We would like to have balance sheets and income statements for Electric Car for the year ending December 31, 1994, but if these are not yet available, we would be w illing to accept statements for E.T.C. Industries (or its predecessor Bradsue Resources, Ltd.) for the year ending December 31, 1991. If the information reflected in the financial statements is given in Canadian dollars, please provide a key indicating the value in American dollars on December 31 of each year for which the information is provided.

In order to grant a hardship application, the Administrator must find that an applicant has tried to comply in good faith with each standard for which exemption is requested. Your application contains no information upon which the Administrator could ma ke such a finding with respect to any of the six standards for which you seek exemption. In spite of your confidence about the MI-6's performance in a 30 mph barrier impact, the fact that the MI-6 uses equipment installed in motor vehicles that are cert ified as meeting the Federal motor vehicle safety standards does not mean that the MI-6 will meet any of the six standards with the equipment installed. We therefore suggest that you supplement the application with information demonstrating that you hav e examined each of the six standards in some detail, and have made a study of possible compliance problems and possible solutions to them. It is permissible to ask to be excused from only a portion of a standard, and you may find, after studying your pr oblems, that you will be able to narrow your requests for exemption from Standards No. 201 and 208. We assume with respect to the latter that you are concerned with the airbag requirements. Although your letter speaks of "restraint systems", we would l ike your further identification of them as two-point (lap belt) or three-point (lap and shoulder belt) systems.

Although you appear to be a manufacturer in the start-up stage and one whose total motor vehicle production in the year preceding the filing of the application was far less than 10,000, you have omitted to provide the number of motor vehicles that you pr oduced in 1994 which is information that we require. Please do so in your response to this letter.

When we have received this information, we shall prepare a notice requesting public comment which will appear in the Federal Register. We shall notify you when the Administrator has made a decision. We expect this to be three to four months after we ha ve received your further submission. If you have any questions on our requirements, you may call Taylor Vinson of this Office (202-366-5263).

ID: nht95-1.65

Open

TYPE: INTERPRETATION-NHTSA

DATE: February 14, 1995

FROM: Philip R. Recht -- Chief Counsel, NHTSA

TO: David O'Neil -- Hehr International Inc.

TITLE: None

ATTACHMT: ATTACHED TO 12/6/94 LETTER FROM DAVID O'NEIL TO PHILIP R. RECHT (OCC 10574)

TEXT: This responds to your inquiry about Federal Motor Vehicle Safety Standard No. 205, Glazing Materials, with respect to the labeling of glazing installed on transit buses. You stated that the passenger and driver side window glazing on certain transit bus es will be a glass-plastic composite consisting of 1/4 inch tempered glass with DuPont Spallshield 307 plastic laminated to the interior surface. You asked whether this glazing must be certified and marked as Item 15B/16B glazing or whether it is possib le to certify and mark the glazing as Item 2/3. You also asked whether taping the required cleaning instructions to the glazing satisfies the requirements of paragraph S5.1.2.10.

Question One: Must the glazing be certified and marked as Item 15B/16B or is it possible to certify and mark the glazing as Item 2/3?

The glazing described in your letter is tempered glass-plastic and therefore must be certified and marked as either Item 15B or 16B glazing. Item 2 and Item 3 glazing refers to glass, not glass-plastic glazing. It would be incorrect to certify and mark a glass-plastic item of glazing as glass.

Question Two: Does a label containing all required instructions which is taped to the glazing satisfy the requirements of paragraph S5.1.2.10?

Paragraph S5.1.2.10(a) states that

Each manufacturer of glazing materials designed to meet the requirements of S5.1.2.1, S5.1.2.2, S5.1.2.3, S5.1.2.4, S5.1.2.5, S5.1.2.6, S5.1.2.7, or S5.1.2.8 shall affix a label, removable by hand without tools, to each item of such glazing material. Th e label shall identify the product involved, specify instructions and agents for cleaning the material that will minimize the loss of transparency, and instructions for removing frost and ice, and at the option of the manufacturer refer owners to the veh icle's Owners Manual for more specific cleaning and other instructions.

S5.1.2.10(a) applies to your Item 15B/16B glazing since the glazing is required to comply with S5.1.2.6 or S5.1.2.8, S5.1.2.10(a) requires a manufacturer to "affix a label, removable by hand without tools . . . ." Taping the instructions to the glazing i s one way to affix a label to glazing that could be removed by hand without tools. Therefore, a manufacturer could comply with the requirements in S5.1.2.10(a) by taping the instructions to the glazing.

I hope this information is helpful. Please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992 if you have any further questions or need additional information.

ID: nht95-1.66

Open

TYPE: INTERPRETATION-NHTSA

DATE: February 14, 1995

FROM: Philip R. Recht -- Chief Counsel, NHTSA

TO: Baysul Parker -- Manager, Safety Department, California Trucking Association

TITLE: None

ATTACHMT: ATTACHED TO 11/20/92 LETTER FROM PAUL JACKSON RICE TO J. LESLIE DOBSON, 7/1/92 LETTER FROM PAUL JACKSON RICE TO GENE FOUTS, 3/19/91 LETTER FROM PAUL JACKSON RICE TO JERRY TASSAN, 5/24/93 LETTER FROM JOHN WOMACK TO JOHN PAUL BARBER, AND 12/21/94 LETTER FROM BAYSUL PARKER TO PAUL JACKSON RICE (OCC 10622)

TEXT: This responds to your letter of December 21, 1994, in which you state that you have received numerous inquiries regarding whether an alterer can change a vehicle's gross vehicle weight rating (GVWR) before the vehicle's first sale. You state that you hav e received similar inquiries concerning changes to the GVWR on used vehicles. You describe these inquiries as coming generally from owners of vehicles with a GVWR in excess of 26,000 pounds who wish to lower the GVWR so that these vehicles may be driven by operators who do not possess a commercial driver's license. From your review of regulations governing vehicle certification that have been issued by the National Highway Traffic Safety Administration (NHTSA), you express the understanding that only a vehicle manufacturer can assign a GVWR, but that either the manufacturer or "an alterer approved by NHTSA" can change the GVWR before the vehicle's first sale. This has led you to ask whether there is a list of NHTSA approved alterers.

Under NHTSA's regulations on vehicle certification, found at 49 CFR Part 567, the manufacturer of a new motor vehicle is responsible for affixing a label to the vehicle that specifies, among other things, the vehicle's GVWR. Section 567.4(g)(3) of those regulations states that the GVWR assigned by the manufacturer "shall not be less than the sum of the unloaded vehicle weight, rated cargo load, and 150 pounds times the vehicle's designated seating capacity." NHTSA requires a vehicle's GVWR to be specif ied on the certification label to inform the vehicle's owners how heavily the vehicle may safely be loaded. NHTSA expects the GVWR to reflect a manufacturer's good-faith evaluation of the vehicle's size, weight, load carrying capacity, and intended use.

Section 567.7 of NHTSA's certification regulations provides that if a vehicle is altered before its first purchase in such a manner that the vehicle's GVWR is different from that shown on the original certification label, the modified GVWR must be specif ied on the label that the alterer affixes to the vehicle. Contrary to your understanding, NHTSA does not approve vehicle alterers, and consequently maintains no list of such enterprises.

You stated that you have received inquires concerning whether the GVWR of a used vehicle can be changed. As detailed in the certification regulations discussed above, a vehicle's GVWR is assigned by its manufacturer as part of the certification process. To avoid statutory violations, the manufacturer must complete the certification process before the vehicle is first sold to a consumer. The GVWR is therefore fixed prior to this first sale. The only exception to this is if the manufacturer seeks to c orrect an error (such as an error in calculation or a typographical error) in the originally assigned GVWR.

NHTSA recognizes no other circumstances in which an originally assigned GVWR can be changed. The agency has stated on a number of occasions that modifications to assigned GVWRs should not be made for reasons relating to the GVWR threshold of the commerc ial driver's license program. This is reflected in the enclosed letters to J. Leslie Dobson, dated November 20, 1992, Gene Fouts, dated July 1, 1992, and Jerry Tassan, dated March 19, 1991. The commercial driver's licensing program is administered by t he Federal Highway Administration. If you have any further questions concerning licensing requirements for operators of commercial motor vehicles, you should contact Mr. James Scapellato, Director, Office of Motor Carrier Standards, HCS-1, Federal Highw ay Administration, 400 Seventh Street, S.W., Washington, D.C. 20590.

I hope this information is helpful. If you have any further questions concerning NHTSA's certification regulations, feel free to contact Coleman Sachs of my staff at the above address, or by telephone at 202-366-5263.

ID: nht95-1.67

Open

TYPE: INTERPRETATION-NHTSA

DATE: February 14, 1995

FROM: Tamera Reuvers -- Quality Assurance Manager, Viracon/Curvlite

TO: Philip Recht -- Chief Council, NHTSA

TITLE: NONE

ATTACHMT: ATTACHED TO 4/10/95 LETTER FROM PHILIP RECHT TO TAMERA REUVERS (A43; STD. 205)

TEXT: Mr. Recht,

I am respectfully requesting an official ruling/interpretation of 49 CFR Ch. V (10-1-91 Edition) section 571.205 Standard No. 205, Glazing materials. The section in question is section S6. Certification and marking, S6.1 states "Each prime glazing mate rial manufacturer, except as specified below, shall mark the glazing materials it manufactures in accordance with section 6 of ANSI Z26. The material specified in S5.1.2.2 . . . . shall be identified by marks AS 11C, . . . . respectively. A prime glazi ng material manufacturer is one who fabricates, laminates, or tempers the glazing material." Below is our scenario:

We purchase bent tempered product from fabricator "X", which is standard AS-2 designation material according to ANSI Z26. We laminate a piece of SentryGlas tm to the bent tempered product. This now will make the material an AS-15B designation according to ANSI Z26. My question is how should this product be properly marked. Should the primary tempered supplier, fabricator "X", have their marking (AS-2, model number and DOT number) on the product in addition to our marking (AS-15B, model number and Do t number)?

I have never seen a piece of automotive glass with two markings on it. I understand, if we only put our designation on the product, we will be fully responsible for the product. Would it be appropriate to have both prime manufacturers markings on it?

With any inquiries, please feel free to contact me. My hours are 7:00 am to 4:00 pm Monday through Friday. My number is 800-533-0482 Ext. 373.

Immediate attention to this matter would be greatly appreciated.

ID: nht95-1.68

Open

TYPE: INTERPRETATION-NHTSA

DATE: February 14, 1995

FROM: Merridy Gottlieb

TO: Mary Versailles, Office of Chief Counsel, NHTSA

TITLE: NHTSB Letter of Exemption

ATTACHMT: ATTACHED TO 4/25/95 LETTER FROM JOHN WOMACK TO MERRIDY R. GOTTLIEB (A43; STD. 207; STD. 208; VSA 108(A)(2)(A))

TEXT: Dear Ms. Versailles:

Per our conversation today, I am requesting a National Highway Traffic Safety Administration letter of exemption for a modification to my 1995 Chrysler Concord. I am disabled and need 3-4" of additional room for the passenger seat to allow my legs to straighten on long trips. I have two replaced hips and arthritis in my knees. If I leave my legs slightly bent at the knees for long periods of time. I suffer too much pain to be active at the end of the drive. By allowing my legs to straighten all t he way out, there is no pain at all.

Mr. Robert Kitts of Auto Access has agreed to make the slight modification if I can secure your letter of exemption. His service is not local, but he will make a trip to Baltimore for this purpose.

Incidentally, the Automobile Accessibility hotline at Chrysler apparently does not know of your existence and was not aware of any exemptions that could be issued. After repeated phone calls, they said they could not help me and referred me to the Na tional Highway Traffic Safety Board hotline who was also unaware of any exemptions I could get. She was quite adamant that the design alteration would interfere with the functionality of the airbag and could not be done. When I again mentioned in closi ng that I was disabled and asked if anything at all could be done, referred me to "Ms. O'Neill" at the handicapped office in Washington. It turned out that she gave me the wrong name, but I did eventually find Ms. Dalrymple and she lead me to you. Plea se send a memo to the Chrysler Accessibility hotline supervisor and the NHTSB hotline operators informing them that you do exist for these types of problems. It may prevent someone less tenacious than me from giving up and accepting the many years of pa in.

Thank you very much for your quick telephone response.

Sincerely,

ID: nht95-1.69

Open

TYPE: INTERPRETATION-NHTSA

DATE: February 15, 1995

FROM: Tilman Spingler -- ROBERT BOSCH GMBH

TO: Chief Counsel -- NHTSA

TITLE: FMVSS 108, S.4 Definitions, bonded [Illegible Words]

ATTACHMT: ATTACHED TO 3/8/95 LETTER FROM PHILIP R. RECHT TO TILMAN SPINGLER (REDBOOK 2; STD. 108)

TEXT: Request for interpretation:

Dear Chief Counsel,

We ask you kindly to check if this proposal for a lens-reflector-joint can be considered as conforming to the appropriate definition in FMVSS 108.

Thanks in advance for your efforts Best regards

ID: nht95-1.7

Open

TYPE: INTERPRETATION-NHTSA

DATE: January 4, 1995

FROM: Philip R. Recht -- Chief Counsel, NHTSA

TO: Mr. Harold Sousa

TITLE: NONE

ATTACHMT: Attached to 8/31/94 letter from Harold Sousa to NHTSA Counsel

TEXT: Dear Mr. Sousa:

This responds to your letter asking about whether you can import a product into the United States. You stated that the product uses air pressure from a vehicle's brake system to "prevent the air from escaping from the tires of trucks and buses" and "kee ps air pressure in the case of puncture (sic)." I am pleased to have this opportunity to explain how this agency's requirements apply to the manufacture and importation of such a product. The following represents our opinion based on the facts provided in your letter.

By way of background information, this agency, the National Highway Traffic Safety Administration (NHTSA), regulates the manufacture of motor vehicles and motor vehicle equipment. Under our governing statute, the manufacturer must certify that its vehic le or equipment complies with all applicable Federal motor vehicle safety standards (FMVSS). Importers are included in the definition of "manufacturer" under our statute.

NHTSA does not have any specific regulations covering a tire pressure device such as you describe. However, since this device is tied into a vehicle's air brake system, it could affect a vehicle's compliance with Standard No. 121, Air Brake Systems.

If the device is installed as original equipment on a new vehicle, the vehicle manufacturer is required to certify that, with the device installed, the vehicle satisfies the requirements of all applicable Federal safety standards. If the device is added to a previously certified new motor vehicle prior to its first sale, the person who modifies the vehicle would be an alterer of a previously certified motor vehicle and would be required to certify that, as altered, the vehicle continues to comply with all of the safety standards affected by the alteration.

One relevant issue is whether your device is considered an integral part of the brake system in the sense that it would need to comply with certain of Standard No. 121's requirements. A related issue is whether certain parts of the device are considered brake hoses and therefore subject to the requirements of Standard No. 106, Brake Hoses.

We do not have sufficient information about your device to specifically address these issues. I can advise you, however, that your device would not be considered part of the braking system if it were separated from the vehicle's main braking system by a check valve in such way that the main braking system would not be affected by a leakage failure in the device. Moreover, if your device is not considered to be part of the braking system, it would not be subject to Standard No. 106.

If the device is installed on a used vehicle by a business such as a repair shop, the repair shop would not be required to attach a certification label. However, it would have to make sure that it did not knowingly make inoperative any part of a device o r element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable FMVSS.

You should also be aware that all manufacturers headquartered outside of the United States must designate a permanent resident of the United States as the manufacturer's agent for service of process, notices, orders, and decisions. This designation is to be mailed to the Chief Counsel of NHTSA. In accordance with 49 CFR 551.45, the designation must include the following information:

1. A certification that the designation is valid in form and binding on the manufacturer under the laws, corporate by-laws, or other requirements governing the making of the designation at the time and place where it is made;

2. The full name, principal place of business, and mailing address of the manufacturer;

3. Marks, trade names, or other designations of origin of any of the manufacturer's products which do not bear its name;

4. A statement that the designation shall remain in effect until withdrawn or replaced by the manufacturer;

5. A declaration of acceptance duly signed by the agency appointed, which may be an individual, a firm, or a U.S. corporation; and

6. The full legal name and address of the designated agent.

7. The signature of one with authority to appoint the agency. The signer's name and title should be clearly indicated beneath his signature.

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.