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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 10901 - 10910 of 16510
Interpretations Date
 search results table

ID: nht95-2.8

Open

TYPE: INTERPRETATION-NHTSA

DATE: March 21, 1995

FROM: Stephen M. Padula -- Industry Standards & Government Regulations, Uniroyal Goodrich

TO: Walter K. Myers -- NHTSA, Office of the Chief Counsel

TITLE: NONE

ATTACHMT: ATTACHED TO 5/17/95 LETTER FROM JOHN WOMACK TO STEPHEN M. PADULA (A43; PART 575; REDBOOK 2)

TEXT: Dear Mr. Myers:

As discussed in our conversation of March 20, I would like to know if a UTQGS Treadwear grade of 00 or 000 is permissible. My contention is that it would be because of the following argument.

According to 49 CFR @ 575.104(d)(2)(i), "Each tire shall be graded for treadwear performance with the word "TREADWEAR" followed by a number of two or three digits representing the tire's grade for treadwear, expressed as a percentage of the NHTSA nominal treadwear value . . .". Further, @ 575.104(e)(2)(ix)(F) requires the computation of "the percentage (P) of the NHTSA nominal treadwear value . . . using the following formula":

P = Projected mileage / 30,000 X 100

The computed value of P is then rounded to the nearest lower 20-point increment (after September 1, 1993).

Using a hypothetical example of a tire with projected mileage of 5,000 miles would result in the following value for P:

P = 5,000 / 30,000 X 100 = 16.67

Rounding the above number to the nearest lower 20 point increment would result in a grade of 0. Since 2 or 3 digits are required the grade would become 00 or 000.

I would appreciate your response as soon as possible.

ID: nht95-2.80

Open

TYPE: INTERPRETATION-NHTSA

DATE: May 12, 1995

FROM: Robert C. Maltzahn -- Attorney At Law

TO: John Womack Esq -- Acting Chief Counsel, NHTSA

TITLE: Re: Jet Edge Mobile Equipment

ATTACHMT: ATTACHED TO 6/27/95 LETTER FROM JOHN WOMACK TO ROBERT CHARLES MALTZAHN (A43; VSA 102(3))

TEXT: Dear Mr. Womack:

I am corporate counsel for Jet Edge, a company that manufactures ultra-high pressure waterjet cutting and cleaning equipment in Minneapolis, Minnesota. Jet Edge sells the equipment throughout the United States and internationally and some of the equi pment is manufactured as a mobile trailer. I have included a piece of literature from Jet Edge which shows one of the older pumps, but the newer pumps, which are now designated as 36-250D's, are very similar and weigh approximately the same amount.

The equipment is manufactured for use in the construction industry for hydrodemolition and cleaning and for industrial use or for the rental markets where the end user does not wish to purchase the equipment. The equipment is mobile so as to be towed from job to job or from industrial site to industrial site but is not used primarily on the roadways and highways of the United States.

My question is: does the mobile equipment meet the definition of a trailer set forth in 49 CFR sec. 571.3 so as to come under the Federal Motor Vehicle Safety Standards and Regulations and thus require a vehicle identification number (VIN) which would require us to meet the specifications and regulations and the content requirements for the VIN. We would prefer, obviously, because of the nature of the equipment, not to have to establish a VIN and the content requirement thereof.

Therefore, I would request from you a short letter statement as to your opinion as whether the equipment, as described, does or does not require a VIN so that I might in turn give my opinion to those infrequent individuals that so request from us. I might point out that there are less than 50 of these units manufactured per year and the total number in existence at the time of this letter is, to the best of my knowledge, less than 250 worldwide.

If you have any questions with reference to the above, please contact my office.

Enclosure - Brochure omitted.

ID: nht95-2.81

Open

TYPE: INTERPRETATION-NHTSA

DATE: May 17, 1995

FROM: Douglas C. Helbig -- Vice President, SPENCER TESTING SERVICES, Inc.

TO: John Womack -- Acting Chief Counsel, NHTSA

TITLE: NONE

ATTACHMT: ATTACHED TO 6/7/95 LETTER FROM JOHN WOMACK TO DOUGLAS C. HELBIG (A43; STD. 304)

TEXT: Dear Mr. Womak:

I am writing in reference to a telephone conversation I had with Marvin Shaw of NHTSA on May 16, 1995 regarding written verification of NHTSA's power to regulate the re-inspection of Compressed Natural Gas (CNG) containers used as fuel tanks on Altern ative Fuel Vehicles.

It is our understanding that NHSTA does not have any regulatory authority to require periodic reinspection of CNG containers used as a vehicle fuel container. We have been told this by several NHSTA personnel over the phone but they are unwilling to give this to us in writing. Our inability to obtain this in writing has led to considerable confusion for our clients who need to know if D.O.T. or NHTSA does indeed regulate this periodic reinspection.

Simply stated, we need in writing, a letter stating that NHTSA does not have any authority to require periodic inspection of CNG containers used as fuel cells on alternative fuel vehicles.

We thank you for your prompt attention to our request and if you have any questions please do not hesitate to call.

ID: nht95-2.82

Open

TYPE: INTERPRETATION-NHTSA

DATE: May 17, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Stephen M. Padula -- Industry Standards and Government Regulations, Uniroyal Goodrich Tire Company

TITLE: NONE

ATTACHMT: ATTACHED TO 3/21/95 LETTER FROM STEPHEN M. PADULA TO WALTER K. MYERS

TEXT: Dear Mr. Padula:

This responds to your letter of March 21, 1995, in which you asked whether it is permissible to have a treadwear grade of 00 or 000 on tires under the Uniform Tire Quality Grading Standards (UTQGS), 49 CFR 575.104. The answer to your question is yes.

As you know, the UTQGS currently provide that all new passenger car tires sold in the United States must be graded by their manufacturers or brand name owners for treadwear, traction, and temperature resistance. The grades must be assessed in accordance with paragraphs (d)(1)(i)(A) and (B) of the UTQGS and must be molded into or onto the tire sidewall.

Paragraph (d)(2)(i) requires the treadwear grade to be expressed as 2 or 3 digits, representing the percentage (P) of the NHTSA nominal treadwear value, computed as follows:

Projected

P = mileage 30,000 X 100

The percentage derived from the above formula is then rounded off to the nearest lower 20-point increment to arrive at the treadwear grade.

In your letter you proposed a hypothetical example of a tire with a projected mileage of 5,000 miles, which would compute as follows:

P = 5,000 30,000 X 100 = 16.67

Rounded off to the nearest lower 20-point increment, the treadwear rating for that tire would be 00 or 000.

Your example would be correct, if tires still exist that have a projected tread life of 5,000 miles. Although NHTSA has not found any tires so rated, under the current provisions of the UTQGS, it is possible, as demonstrated by your example, to have a U TQGS treadwear rating of 00 or 000.

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

ID: nht95-2.83

Open

TYPE: INTERPRETATION-NHTSA

DATE: May 17, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Dietmar K. Haenchen -- Manager, Vehicle Regulations, Volkswagen of America, Inc.

TITLE: NONE

ATTACHMT: ATTACHED TO 3/13/95 LETTER FROM DIETMAR K. HAENCHEN TO PHILIP R. RECHT (OCC 10790)

TEXT: Dear Mr. Haenchen:

This responds to your request for an interpretation of Standard No. 118, Power-operated window, partition, and roof panel systems. You asked whether the "squeezing force limitation" of S5 applies only to the first attempt to close a power operated window , partition, or roof panel system (power-operated system) and not to immediately following attempts to close. You explained that an operator may initiate more than one closing attempt in order to assure the closing of the power operated system under adv erse conditions such as low temperature or the presence of ice in the power operated system's track. As discussed below, the S5 squeezing force limitation applies to each closing attempt.

By way of background information, Standard No. 118 requires that a power operated system, while closing, must comply with one of two alternative provisions. The first, S4, generally specifies requirements for situations where a person is expected to be in the immediate vicinity of the vehicle to supervise the closing. The second, S5, covers "unsupervised" closings, i.e., automatic closings or closings where the person initiating the closing is further away from the vehicle.

In the rulemaking establishing S5, NHTSA recognized that unsupervised closings increase the risk that persons, especially children, could be caught between a closing system and the frame. Therefore, to the extent that a power operated system permits uns upervised closings, the agency decided to require an automatic reversal mechanism that reverses the window direction upon its meeting an obstruction. More specifically, if an obstruction is between 4 and 200 mm from any part of the vehicle structure wit h which the closing system mates, S5 requires window reversal before a force of 100 Newtons is encountered.

S5 does not specify different squeezing force limitation requirements for different closing attempts. Therefore, a power operated system must meet the same requirements for each closing attempt. We note that since the requirements of S5 address unsuper vised closings, the same safety concerns about children being caught between a closing system and frame would be relevant to each closing attempt.

I note that NHTSA decided not to apply the S5 squeezing force limitation requirement to unsupervised closings within the area between 4 mm and any part of the vehicle structure with which the closing system mates. The agency recognized that injury from system closure is not possible in this area, and that unnecessary automatic reversal could result from the system's misalignment or obstruction from ice. Thus, during unsupervised closing, if the system encounters an obstruction less than 4 mm from any part of the vehicle structure with which the closing system mates, the power operated system need not reverse.

I hope that this information is helpful. If you have any further questions, please contact Dorothy Nakama of my staff at (202) 366-2992.

ID: nht95-2.84

Open

TYPE: INTERPRETATION-NHTSA

DATE: May 17, 1995

FROM: Phyllis Armstrong -- General Sales Manager, Saturn of Puyallup (Washington)

TO: Phillip Reckt, Chief Counsel, NHTSA

TITLE: Phone Conference Evonne Ropell and Dick Morris

ATTACHMT: ATTACHED TO 11/28/95 LETTER FROM Samuel J. Dubbin to Phyllis Armstrong (A43; Part 580); Also attached to 7/20/89 letter from Kathleen DeMeter to B.L. Swank

TEXT: Dear Mr. Reckt:

On May 17th, 1995, I called Nancy Kelly, Administrator of Department of Licensing for the State of Washington, regarding the towing mileage on the Saturn. As you may or may not be aware, the mileage on the Saturn does not register as the car is being to wed. Only driven miles record on the odometer. Nancy Kelly said she would investigate by having her office communicate with the National Highway Traffic Safety Association in Washington, D.C. and have a definitive answer for me today.

I soon received a phone call from Evonne Ropell, Nancy Kelly's assistant, who had just completed a phone conference with Dick Morris. Evonne said that the NHTSA was well aware that Saturns did not record towed miles, and that the actual miles driven are what is to be recorded on the odometer statements. For example if a Saturn is towed and reflects 10,000 miles on the odometer, then the odometer statement should show 10,000.

I am requesting a letter confirming these findings, as it is crucial information in our daily business affairs. It is terrific to have an agency that is readily available and supportive.

ID: nht95-2.85

Open

TYPE: INTERPRETATION-NHTSA

DATE: May 18, 1995

FROM: Jane L. Dawson -- Specifications Engineer, Thomas Built Buses, Inc.

TO: Walter Myers -- Chief Counsel's Office, NHTSA

TITLE: NONE

ATTACHMT: ATTACHED TO 8/4/95 LETTER FROM JOHN WOMACK TO JANE L. DAWSON (A43; STD. 217; REDBOOK 2)

TEXT: Dear Mr. Myers,

Please provide an interpretation on the following:

In the final rule for FMVSS 217, Bus Emergency Exits and Window Retention and Release published in the Federal Register May 9, 1995, what are the location requirements (fore and aft) for emergency windows which may now be used as the first additional eme rgency exit?

Your quick response is appreciated.

ID: nht95-2.86

Open

TYPE: INTERPRETATION-NHTSA

DATE: May 18, 1995

FROM: Jim Burgess -- Engineering Manager, Independent Mobility Systems, Inc

TO: Walter Myers -- Chief Council, NHTSA

TITLE: NONE

ATTACHMT: ATTACHED TO 8/4/95 LETTER FROM JOHN WOMACK TO JIM BURGESS (A43; REDBOOK 2; STD. 206)

TEXT: Dear Mr. Meyers:

Per our conversation earlier today, I am writing to learn your interpretation of 49CFR, 571.206, S4, as it pertains to our vehicles.

As we discussed, for eight (8) years, Independent Mobility Systems, Inc., has been converting Chrysler minivans, and recently Ford minivans, into wheelchair accessible vehicles by lowering the floor and adding a wheelchair ramp in the passenger side rear sliding door area. We have crash tested these converted vehicles at OTRC in Ohio for FMVSS 571.208 Frontal Impact, and for FMVSS 571.301 Rear Impact and Side Impact, to gain certification.

In regard to 49CFR, 571.206, S4, our interpretation is that side doors on motor vehicles which are equipped with wheelchair lifts, and linked to an alarm system consisting of either a flashing visible signal located in the driver's compartment or an alar m audible to the driver which is activated when the door is open, need not conform to this standard, pertains to our converted vehicles. We believe the wheelchair ramp we employ serves the same function as a wheelchair lift, in that it provides those per sons in wheelchairs or access to the vehicle, and thus we do not have to conform to this standard.

Because we have had inquiries from customers on this issue, your written interpretation to our inquiry will be appreciated.

ENCLOSURE

June 16, 1995

Dear Mr. Meyers:

As per our telephone conversation this morning, I am sending the enclosed brochures on our current offerings. As I stated, we are working on converting the new 1996 Chrysler NS minivans. We are scheduled for crash testing this vehicle the latter part o f July and offer it for sale in mid-August.

If you have any further questions before ruling on our request of May 18, 1995, regarding interpretation of 49 CFR, 571.206, S4, please call me.

Sincerely,

INDEPENDENT MOBILITY SYSTEMS, INC.

Jim Burgess Engineer

Enclosure: RAMPVAN BROCHURE/PHOTOS OMITTED

ID: nht95-2.87

Open

TYPE: INTERPRETATION-NHTSA

DATE: May 19, 1995

FROM: Don Bearden -- Director, Governmental Affairs

TO: John Womack -- Acting Chief Counsel, NHTSA

TITLE: Interpretation of 49 CFR Part 581, Bumper Standard

ATTACHMT: ATTACHED TO 6/9/95 LETTER FROM JOHN WOMACK TO DON BEARDEN (A43; PART 581)

TEXT: Dear Mr. Womack:

Subaru of America, Inc. is considering the use of an optional rear bumper-mounted spare tire carrier on a future vehicle as shown on the attached sketch. All trim levels of this vehicle would be offered both with and without the optional rear spare t ire carrier. (For vehicles without the optional external carrier, the spare tire would be carried inside the vehicle). At this time, we can only estimate the sales appeal of this option, but project that it will be specified for far less than 50% of th e car line.

The bumper test conditions contained in 49 CFR @ 581.6(5) specify that "[running] lights, fog lamps, and equipment mounted on the bumper face bar are removed from the vehicle if they are optional equipment." (Emphasis added.)

Since the Subaru optional spare tire carrier would be mounted to the bumper beam and face bar, we understand that the tire and carrier would be removed from the vehicle prior to the conducting of the Part 581 bumper test.

We would appreciate your confirmation of our interpretation.

Thank you for your assistance. Should you or your staff have any questions concerning this request, please contact me at (609) 488-8644

Enclosure

Rear spare tire carrier

without equipment with equipment

(Graphics omitted.)

ID: nht95-2.88

Open

TYPE: INTERPRETATION-NHTSA

DATE: May 19, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Mary J Gazich -- Owner - Clever Kids, Inc.

TITLE: NONE

ATTACHMT: ATTACHED TO 3/23/95 LETTER FROM MARY J. GAZICH TO PHILLIP RECHT (OCC 10327)

TEXT: Dear Ms. Gazich:

This responds to your letter asking about how this agency's regulations might apply to your product, the "Smart Rider." In your letter, you described the Smart Rider as a "new automobile accessory for children." It is a vinyl seat back protector that sli ps over one or both of the front seats and secured, we assume, with the two 3/4 inch elastic bands.

The answer to your question is that there are no standards that apply directly to the Smart Rider, but there are Federal requirements that may affect it. I summarize below the relevant safety standards and laws you should consider.

As you recognized in your letter, the Smart Rider is an accessory, a type of motor vehicle equipment under our regulations. As a manufacturer of motor vehicle equipment, you are subject to the requirements in sections 30118-30122 of Title 49 of the U.S. Code concerning the recall and remedy of products with defects related to motor vehicle safety. In the event that the manufacturer or NHTSA determines that the product contains a safety related defect, the manufacturer would be responsible for notifyin g purchasers of the defective equipment and remedying the problem free of charge.

NHTSA has not issued any standards for an accessory such as the Smart Rider. For that reason, you should not place any label on your packaging to the effect that it meets Federal standards.

Although no standards apply directly to the Smart Rider, its installation may affect vehicle compliance with certain safety standards. NHTSA has issued a safety standard (Standard No. 201, Occupant protection in interior impact) that requires, among oth er things, that seat backs have a certain amount of cushioning to provide protection when struck by the head of rear seat passengers during a crash. Installation of your product on the back of front seats could have an impact on compliance with that sta ndard. If the vinyl of the Smart Rider is stiff enough, it might distribute the impact of the occupant's head over a larger area of the seat back than the vehicle manufacturer intended. As a result, the foam in the seat back might not compress as deepl y as the manufacturer intended, and the requisite amount of cushioning might not be achieved. We do not know how stiff the vinyl is, and this may not be a problem, but it is something of which you should be aware.

Another standard that you might want to consider is Standard No. 302, Flammability of interior materials. That standard requires that seat backs not burn or transmit a flame front across their surface at a rate of more than 4 inches per minute. If the S mart Rider were installed as part of a new vehicle, it would be considered part of the seat back.

Which legal requirements apply depend to some extent on how your product is marketed. If your product were installed by a vehicle manufacturer as original equipment, the vehicle manufacturer would have to certify that the vehicle with the Smart Rider in stalled complies with all FMVSS's, including Standards No. 201 and 302. In addition, although we recognize it would be unlikely that your product would be installed by a motor vehicle manufacturer, distributor, dealer or repair business, section 30122(b ) of title 49 prohibits those commercial businesses from "knowingly mak[ing] inoperative any part of a device or element of design installed on or in a motor vehicle . . . in compliance with an applicable Federal motor vehicle safety standard . . ." For instance, compliance with Standard No. 201 might be degraded if the Smart Rider were mounted in front of rear seat passengers. Any violation of this "make inoperative" prohibition would subject the installer to a potential civil penalty of up to $ 1,000 for each violation.

The "make inoperative" prohibition does not apply to modifications that vehicle owners make to their own vehicles. Thus, our standards would not apply in situations where individual vehicle owners install the Smart Rider in their own vehicles, even if t he installation were to result in the vehicle no longer complying with the safety standards. However, NHTSA encourages vehicle owners not to degrade any safety device or system installed in their vehicles. In addition, individual vehicle owners may mak e to their vehicles, so you might wish to consult State regulations to see whether the Smart Rider would be permitted.

I want to emphasize that NHTSA has not made a determination regarding the safety of the Smart Rider. NHTSA has not done any testing of your product. I am merely informing you of the applicable law and identifying a few potential problem areas for your consideration.

I hope this information is helpful. I am also enclosing a copy of a fact sheet titled "Information for New Manufacturers of Motor Vehicles and Motor Vehicle Equipment." If you have any further questions about NHTSA's safety standards, please feel free t o contact Mr. Atelsek of my staff at this address or by telephone 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.