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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 5841 - 5850 of 16490
Interpretations Date

ID: 14054.drn

Open

Mr. Mike Hofstätter
Steyr-Daimler-Puch
Fahrzeugtechnik AG & Co KG
Liebenauer Hauptstraße 317
A-8041 Graz
AUSTRIA

Dear Mr. Hofstätter:

This responds to your request for information whether a vehicle your company is considering manufacturing may be classified as a "multipurpose passenger vehicle." As explained below, we need more information to make this determination.

Please note that under NHTSA's statutory authority (49 U.S.C. Chapter 301 Motor Vehicle Safety) the vehicle's manufacturer is responsible in the first instance for classifying a particular vehicle. NHTSA does not approve or endorse any vehicle classification before the manufacturer itself has classified a particular vehicle. NHTSA may reexamine the manufacturer's classification during the course of an enforcement action.

"Multipurpose passenger vehicle" is defined in our regulations at 49 CFR 571.3 as "a motor vehicle with motive power, except a trailer, designed to carry 10 persons or less which is constructed either on a truck chassis or with special features for occasional off-road operation."

Your letter informed us that you are designing a "passenger car" with dimensions similar to a Volkswagen Golf, with four side doors, one rear door, two front seats and three rear seats. Your letter further states that the vehicle has a front wheel drive, and the body "will be lifted up for 50 to 60 mm, so that the vehicle can be used for occasional off-road operation."

Based on your description, it appears that the vehicle is designed to carry fewer than 10 persons (as it has five seats). Part of "multipurpose passenger vehicle's" definition is that it has "special features for occasional off-road operation." The only "special feature" you have described is the body is raised 50-60 mm. We cannot agree that raising the body 50-60 mm alone is commensurate with equipping the vehicle with special features for off-road operation.

Before determining whether your vehicle could be classified as a "multipurpose passenger vehicle," we must know whether the vehicle has other special features. If your vehicle has other features for occasional off-road operation, please write to let us know what they are. After reviewing the additional information, we will be able to make an informed decision.

I am enclosing an information sheet for new manufacturers of motor vehicles. For further information, please feel free to contact Dorothy Nakama of my staff at this address or at (202) 366-2992.

Sincerely,

John Womack

Acting Chief Counsel

Enclosure

ref:571.3

d:4/21/97

1997

ID: aiam2958

Open
Mr. J. C. Eckhold, Director, Automotive Safety Office, Ford Motor Company, The American Road, Dearborn, MI 48121; Mr. J. C. Eckhold
Director
Automotive Safety Office
Ford Motor Company
The American Road
Dearborn
MI 48121;

Dear Mr. Eckhold: This responds to your recent petition to amend Safety Standard No. 210 *Seat Belt Assembly Anchorages*, to exempt active lap belts installed in conjunction with passive upper torso restraints from the anchorage location requirements of the standard.; The agency has determined that amendment of the standard as you reques is unnecessary since active lap belts and their associated anchorages are not required to comply with Federal safety standards if installed voluntarily by a manufacturer in addition to a single, diagonal passive belt. The passive restraint requirement of Safety Standard No. 208 will require passive protection in frontal crashes and, either passive protection in lateral and rollover crash modes or the provision of Type I or Type II active belts for protection in lateral and rollover crash modes. The agency has previously stated, most recently in a letter to Volkswagen dated August 1, 1977, that the provision in S4.5.3 of Standard No. 208 allowing the substitution of any passive belt system (whether or not including a lap belt) for any other belt system otherwise required, is intended to apply to the provisions of S4.1.3(c) that specify either passive protection or the provision of Type I or Type II belts.; Since active lap belts installed in conjunction with single, diagona passive belts are not required, they are voluntary additions by the manufacturer. The agency has stated in past interpretations that systems or components installed in addition to required safety systems are not required to meet Federal safety standards, provided the additional components or systems do not destroy the ability of required systems (the passive belt in this case) to comply with Federal safety standards. This means that your proposed restraint system would have to meet the frontal crash protection requirements of Standard No. 208 both with and without the active lap belt fastened.; Since the change you requested is unnecessary in light of thi interpretation, the agency will consider your petition withdrawn.; Sincerely, Frank Berndt, Acting Chief Counsel

ID: nht68-3.17

Open

DATE: 03/02/68

FROM: AUTHOR UNAVAILABLE; Joseph R. O'Gorman; NHTSA

TO: Field Body Company Inc.

TITLE: FMVSR INTERPRETATION

TEXT: Thank you for your letter of January 8, 1968, in regard to certification of your product and questions regarding interpretation of the Chassis-Cab regulation.

In regard to your letter furnishing us certification information, what you have provided will be very useful to us; however, in accordance with Section 112 of the National Traffic and Motor Vehicle Safety Act of 1966, it would be appreciated if you would provide us with an actual sample of your certification label and the method of attachment.

Concerning your request for clarification in regard to the extent of responsibility for adherence to applicable safety standards to your type of vehicle, the following should be of assistance:

First, your vehicle, completed, falls into the category defined as a "truck" and as such, must adhere to Safety Standards 102, 107, 108, 205 and 209. We have enclosed a copy of the Federal Register, Volume 32, No. 23, dated February 3, 1967, and several other pertinent amendments.

Regarding extent of responsibility of the chassis-cab body manufacturer, and final assembler of the units into a completed vehicle, these are clarified in Section 2 you refer to in your letter. I assume this is Federal Register Volume 33, No. 1, dated January 3, 1968, "Notice of Ruling regarding Chassis-Cabs," but in case it is not I am enclosing a copy for your reference. This notice defines two main points which I will endeavor to state in a few words as follows:

If the original manufacturer of the chassis, after January 1, 1968, cannot or does not include all the safety standard regulations required for the type of end product or completed assemblage, then the final assembler is responsible to certify that all applicable safety standards are included and the vehicle is so certified and labeled.

Thank you for your interest in the safety program.

ID: 86-5.21

Open

TYPE: INTERPRETATION-NHTSA

DATE: 09/16/86

FROM: JEROME A. CZARNOWSKI

TO: CARL CLARK -- INVENTOR CONTACT NHTSA

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 06/04/87, TO JEROME A CZARNOWSKI FROM ERIKA Z. JONES, REDBOOK A30 (2), STANDARD 121

TEXT: Dear Dr. Clark,

Enclosed are copies of the un-edited and published versions of the article on the Emergency Air Reserve System (EARS) of which we spoke this morning. I retained copyright, while granting FIRE COMMAND one-time publication rights, which is our usual arrangement.

Basically, EARS is a separate high-pressure system intended to provide an emergency vehicle with enough air volume and pressure to charge the vehicle's integral system to operating pressure. Depending upon the volume of the integral system, this can be accomplished in four to ten seconds versus two to five minutes using the vehicle's air compressor from O PSI. In our business, cutting the response time in any emergency can mean life or death for the victim.

This system does not violate the integrity of the vehicle's system, since check-valves, a relief valve and one-way regulator are present. The components of the system are proven under the most demanding and abusive conditions.

The article points out other advantages to the system, and how some apparatus manufacturers are providing to solve the initial air-pressure problem. I doubt if some of the solutions I've seen (i.e., on-board diaphram compressors tied to the "wet tank") solve more problems than they create. I have also seen electrical air-selenoids on the discharge ports of air tanks to shut the tanks off when not in use (parked). Can you imagine the result if the electrical system fails while a fire engine is responding to a scene?

Thank you for your time in evaluating this device. As I stated over the phone, the Patent prospect looks favorable. However, I am more concerned with the safety for both the firefighter and the public.

Sincerely,

ID: nht75-6.14

Open

DATE: 08/19/75

FROM: AUTHOR UNAVAILABLE; Frank A. Berndt; NHTSA

TO: South Texas Tire Test Fleet

TITLE: FMVSR INTERPRETATION

TEXT: This is to confirm your telephone conversation of July 31, 1975, with Mark Schwimmer concerning the treadwear test procedures specified in 49 CFR Part 575.104, Uniform Tire Quality Grading Standards (UTQGS).

You had previously pointed out that the A78-13 and other tires are available neither as original equipment nor as recommended replacement options on any 1975 model passenger cars, although they are available as replacement options for the 1974 Ford Pinto. You had asked whether it is permissible for a tire manufacturer to conduct treadwear testing for such tires on a 1975 Pinto, in light of the National Highway Traffic Safety Administration's (NHTSA) statement that

tires will be tested for compliance only on vehicles for which they are available as original equipment or recommended replacement options. (40 FR 23076, May 28, 1975)

As Mr. Schwimmer explained to you, the UTQGS rules does not dictate the method by which a tire manufacturer must conduct his testing to assign grades. It merely specifies the procedures which the NHTSA will follow when testing tires for compliance with the rule. While the surest way for the tire manufacturer to be confident of compliance would be to follow these procedures in every detail, he is not legally obligated to do so. His obligation is simply to ensure that, when tested by the NHTSA according to the specified procedures, his tires are capable of achieving the grades which he has assigned to them. He may fulfill this obligation by whatever means he believes reliable and necessary. Thus, for example, he might choose a 1975 Pinto to test an A78-13 tire, if he is confident that the model year change in the Pinto will have no effect on the tire's treadwear performance. This decision is his, however. The NHTSA, in its compliance testing, would test such a tire on a 1974 Pinto or on some other passenger car for which it is original equipment or a recommended replacement option.

ID: 1983-1.1

Open

TYPE: INTERPRETATION-NHTSA

DATE: 01/01/83 EST.

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: Mr. Richard R. Kelm -- Manager of Automotive Glass Replacement Services, Libby-Ownes - Ford Company

TITLE: FMVSS INTERPRETATION

TEXT:

This responds to your letter of September 24, 1983, regarding the certification and marking requirements for glazing under S6 of Safety Standard No. 205, Glazing Materials. You stated that you are interested in "out-sourcing some of your replacements auto glass requirements" to other manufacturers and sought clarification on four points concerning glazing identification.

Section 6 of Standard No. 205 deals specifically with the certification and marking requirements for glazing materials. The standard incorporates by reference the American National Standard "Safety Code for Safety Glazing Materials for Glazing Motor Vehicles Operating on Land Highways," Z26.6-1966 (ANS Z26). You ask whether it is permissible under National Highway Traffic Safety Administration (NHTSA) regulations to allow another manufacturer, using its own DOT code mark, to put an LOF trademark and logo on its glass.

Section 6 of ANS 226 states that a manufacturer shall mark safety glazing materials with its own "distinctive designation or trademark." The purpose behind these markings was to aid in the tracing of glazing materials and the enforcement of applicable standards. Your letter states that the other manufacturer will place their DOT code mark on the safety glass. Since the other manufacturer is using its own DOT code mark, the tracing and enforcement policies will not be circumvented. Therefore, under these circumstances, the use of LOF's logo and trademark is not violative of Standard No. 205.

Further, you ask whether another glass manufacturer can use LOF's "M" number on his glass with LOF's permission. As long as the model number is an accurate description of the specified glazing material being produced, the other manufacturer may use it.

Lastly, you ask if the name of the country of manufacture must appear on the safety glass if not manufactured in the United States. The standard does not mandate that the country of manufacture be marked on the safety glazing materials.

Original Signed by Frank Berndt, Chief Counsel

ID: nht94-2.6

Open

TYPE: Interpretation-NHTSA

DATE: March 29, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Tom Delapp -- Executive Coach Builders, Inc. (Springfield, MO)

TITLE: None

ATTACHMT: Attached to undated letter from Tom Delapp to Chief Council, NHTSA (OCC 8868)

TEXT:

This responds to your letter requesting an interpretation of Federal Motor Vehicle Safety Standard (FMVSS) No. 206, "Door locks and door retention components," as it pertains to the locking mechanism of a so-called "5th" door installed on your limousines . I apologize for the delay in responding. We conclude that the locking mechanism on the 5th door is not prohibited by Standard 206.

Based on your letter and a conversation with David Elias of my office, I understand that you have replaced the extra panel on the right side of a 1993 Lincoln Town Car based limousine with a passenger door (i.e., the 5th door). The door consists complete ly of the original equipment manufacturer's materials and hinges. The 5th door is a supplementary door, and does not replace or effect in any way the two side rear doors with which your vehicles are normally equipped.

When the 5th door is closed, its locking mechanism engages automatically, and the door cannot be opened from the inside or the outside. A solenoid locking mechanism that unlocks the 5th door is located inside the vehicle in a "privacy panel" behind the driver's seat. For the driver to unlock the 5th door, the car must be stopped and the driver must then get out of the car and reach through a window into the area behind the driver's seat. The locking mechanism cannot be reached by the driver while sea ted in the driver's seat, and cannot be reached by the passengers in the rear seats. The 5th door cannot be accidentally opened; unless the locking mechanism has been actively disengaged, the door remains locked. Disengaging the locking mechanism for t he 5th door allows the driver to open the door from the outside, although passengers could push the door open from the inside, as well.

There are two pertinent requirements of FMVSS No. 206 to your situation. First, S4.1.3 (Door Locks) states that:

Each door shall be equipped with a locking mechanism with an operating means in the interior of the vehicle.

In two prior letters, to Mr. Charles Murphy on May 10, 1974, and to Mr. Gary Hackett on April 11, 1988, the agency interpreted S4.1.3 to mean that the locking mechanism must also be OPERABLE from within the vehicle.

The first question to be addressed is whether the 5th door meets the requirement of S4.1.3. We believe the answer is yes, the door is equipped with a locking mechanism with an operating means in the interior of the vehicle that is operable from within the vehicle. The operating means for the locking mechanism is in the interior of the vehicle in that the locking mechanism engages automatically when the 5th door is closed. While the means to

disengage the operating mechanism is not accessible to occupants in the vehicle, Standard 206 does not require the locking mechanism to be capable of being disengaged by an occupant. This is because the purpose of the standard is to minimize the chance that occupants of the vehicle will be ejected in a collision. Thus, the thrust of the standard is to ensure that occupants are retained within the vehicle, such as by requiring doors to have door locks that occupants are capable of locking.

The second pertinent requirement is S4.1.3.2 (Side Rear Door Locks), which states that:

... when the locking mechanism is engaged both the outside and inside door handles or other latch release controls shall be inoperative.

The 5th door appears to comply with S4.1.3.2, in that it cannot be opened from the outside or inside when the locking mechanism is engaged.

In a letter to Ms. C.D. Black, dated April 10, 1987, the agency interpreted a question on child safety locks that is relevant to your situation. The child safety lock operated as a "secondary locking system" that, when activated, rendered the inside rea r door handle incapable of opening the door. (It had no effect on the outside door handle.) As we stated in that letter, our conclusion was that Standard 206 permitted the child safety lock because the standard prohibits only secondary locking systems that interfere with the ENGAGEMENT, but not with the DISENGAGEMENT, of the primary locking system. In that letter, we wrote:

The answer to your question about the child locking systems is dependent on whether the systems interfere with an aspect of performance required by Standard No. 206. We have determined that the answer is no, because the requirements of... S4.1.3.2 are written in terms of what must occur when the primary system is engaged and impose no requirements regarding the effects of disengaging the system. Thus, the aspect of performance required by S4.1.3 for the interior operating means for the door locks is that it be capable only of ENGAGING the required door locking mechanisms. The aspect of performance required by S4.1.3.2 for door locks on the rear doors is that the inside and outside door hand les be inoperative when the locking mechanism is ENGAGED. Since we have determined that... S4.1.3.2 do(es) not address the effects of disengaging the required door locks--i.e., S4.1.3.2 does not require that the inside rear door handles b e operative (capable of releasing the door latch) when the required locking system is disengaged--a child locking system may be provided on a vehicle if it does not negate the capability of the door lock plunger (the operating means) to engage the door locks.

I hope this information has been helpful. If you have any further questions, feel free to contact Mr. Elias at the above address or by phone at (202)366- 2992.

ID: aiam3203

Open
Mr. Walter S. Felton, Jr., Hugh A. West, Inc., Suite 303 Professional Building, Suffolk, Virginia 23434; Mr. Walter S. Felton
Jr.
Hugh A. West
Inc.
Suite 303 Professional Building
Suffolk
Virginia 23434;

Dear Mr. Felton: This is in response to your letter of October 22, 1979, addressed t Mr. Nelson Erickson. Please accept my apologies for the lateness of our letter. Your letter asked whether Federal Motor Vehicle Safety Standard No. 114, *Theft Protection*, was intended to prevent a small child or animal left unattended in a parked automobile (model year 1973) from which the keys have been removed, from intentionally or accidentally moving the gear selection level from the 'Park' position. The answer to your question is no, for the reasons noted below. You also requested a copy of any technical analysis that may have been done in the development of Safety Standard 114. Although the public docket contains analyses pertinent to later versions of Safety Standard 114 it contains none pertinent to any version of the standard applicable to passenger cars manufactured in 1973. The only analyses pertinent to these earlier versions of the standard are contained in documents which contain internal agency opinion and recommendations and thus are not publicly available.; When Safety Standard 114 was adopted in 1968 its stated purpose was t 'reduce the incidence of accidents resulting from unauthorized use.' (33 FR 6471, April 27, 1968). This goal was based on evidence which shoed that: 'cars operated by unauthorized persons are far more likely to cause unreasonable risk of accident, personal injury and death than those which are driven by authorized individuals,' (33 FR 6471, preamble). Neither the rule nor the preamble states that the standard was intended to accomplish any other goal.; As adopted, the standard required that all passenger cars manufacture on or after January 1, 1970, be equipped with a key locking system that (upon removal of the key) would prevent 'activation of the car's engine or other main source of motive power, and either steering or self-mobility or both.' Safety Standard 114 in its current form also provides manufacturers with this option. The preamble to the standard simply stated that a steering or self-mobility lock was needed in order '...to defeat car thieves who start cars with so-called 'master keys' and devices which bypass the [ignition] lock ...' (33 FR 6471).; In light of the compliance option described above and the purpose o Safety Standard 114 as expressed both in the standard its self and in the preambles of various Federal Register notices, it appears that Safety Standard 114 was not intended to apply to the situation described in your letter.; If you have any further questions, please fell free to contact Ms Debra Weiner of my staff at 202-426-2992.; Sincerely, Frank Berndt, Chief Counsel

ID: nht74-3.29

Open

DATE: 09/17/74

FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA

TO: The Weatherland Company

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of August 14, 1974, pointing out a discrepancy in the constriction test requirements for hydraulic brake hose found in Federal Motor Vehicle Safety Standard No. 106-74.

We are considering a change in our next notice concerning Standard 106-74, so that S6.7.2(c) will conform with S5.3.1 as that paragraph was amended by Notice 11 (39 F.R. 24012).

Yours Truly,

The Weatherhead Company

August 15, 1974

Reference: MUE 486

Richard B. Dyson Assistant Chief Counsel -- NHTSA

Subject: FMVSS 571.106-74 Reference Notice 11 Docket 1-5

Your timely personal response to our request for clarification of the labeling of 1/8 inch O.D. SAE J844c nylon air brake tubing is sincerely appreciated. The NHTSA's determination to exempt this small sized tubing is reasonable, without adverse effect on vehicle safety, and sustains the usage of an economic product.

While preparing our corporate documentation to support product compliance with 571.106-74 a troublesome inconsistency was noted. Perhaps NHTSA can incorporate a minor change in the wording of Para. S6.7.2(c) in the next publication released concerning The Brake Hose Standard.

Paragraph S6.7.2(c) retains the Constriction Test requirement for the complete brake hose assembly stating: "Drain the brake hose assembly, immediately determine that every inside diameter of any section of the hose assembly is not less than 64% of the nominal inside diameter of the hose, and conduct the test specified in S6.2."

As you may recall Notice 11 excluded end fittings, distribution blocks and residual valves by amending constriction requirements to be applicable to only ". . . that part of the fitting in which hose is inserted".

Realizing this inconsistency in Para. S6.7.2(c) is an oversight and that it would not cause an unnecessary compliance variance, a repetitive petition is withheld pending correction.

Thank you once again for responding so promptly to our requests for clarification concerning this Standard.

John H.Mueller

Manager, Engineering Standards

cc: D. Delve

W. Redler

ID: aiam4852

Open
Mr. Earl C. Lempke President, Delavan Industries, Inc. 1728 Walden Avenue Buffalo, NY 14225; Mr. Earl C. Lempke President
Delavan Industries
Inc. 1728 Walden Avenue Buffalo
NY 14225;

"Dear Mr. Lempke: This responds to your letter of March 6, l991, t Taylor Vinson of this Office. You have asked whether there is 'any Federal ruling stating that Trailer Clearance Lights are considered as Safety Equipment and as such are not be be included as part of the overall width of the vehicle.' You have enclosed a copy of 49 CFR 323.20, the clearance lamp regulation of the Federal Highway Administration (FHWA), with the observation that 'this section does not answer the question.' I am pleased to clarify this situation for you. As the FHWA regulation states, 'Clearance lamps shall be mounted so as to indicate the extreme width of the motor vehicle . . . .' This requirement is virtually identical to that in Table II of this agency's Federal Motor Vehicle Safety Standard No. 108 that clearance lamps be located 'to indicate the overall width of the vehicle . . . .' In l976, NHTSA issued an interpretation that was published in the Federal Register on August 23 of that year stating that 'The term 'overall width' refers to the nominal design dimension of the widest part of the vehicle, exclusive of . . . marker lamps' such as clearance lamps. I enclose a copy for your information. The FHWA concurs with this interpretation, and has provided us with some additional comments. Federal width limits apply only on the National Network highways (23 CFR 658, Section A). The width of commercial trailers operated on these highways is to be measured across the sidemost load carrying structures, support members, and structural fasteners, as stated in an interpretation published on March 13, l987, a copy of which I enclose. That proceeding also determined that side marker lamps and any other 'non load-carrying safety appurtenance' which extended beyond these limits were excluded from width measurements. This would include clearance lamps, and thus exclude them also from width measurements. In December 1989, FHWA issued an advance notice of proposed rulemaking to consider if a new approach should be adopted to determine which devices to exclude from measurements of vehicle length and width. I also enclose a copy of that notice. FHWA advises that its next notice on the subject should be issued soon. Although under FHWA regulations, the States determine whether safety equipment is to be excluded from the measurement of vehicle width, we believe that the State determination must be identical to the NHTSA position. Federal law (l5 U.S.C. 1392(d)) prohibits a State from enacting or maintaining in effect any regulation covering the same aspect of performance as a Federal motor vehicle safety standard unless it is identical to the Federal requirement. We believe that a State must also interpret an identical regulation in a manner identical to NHTSA's interpretation. Sincerely, Paul Jackson Rice Chief Counsel Enclosure";

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.

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