
NHTSA Interpretation File Search
Overview
NHTSA's Chief Counsel interprets the statutes that the agency administers and the standards and regulations that it issues. Members of the public may submit requests for interpretation, and the Chief Counsel will respond with a letter of interpretation. These interpretation letters look at the particular facts presented in the question and explain the agency’s opinion on how the law applies given those facts. These letters of interpretation are guidance documents. They do not have the force and effect of law and are not meant to bind the public in any way. They are intended only to provide information to the public regarding existing requirements under the law or agency policies.
Understanding NHTSA’s Online Interpretation Files
NHTSA makes its letters of interpretation available to the public on this webpage.
An interpretation letter represents the opinion of the Chief Counsel based on the facts of individual cases at the time the letter was written. While these letters may be helpful in determining how the agency might answer a question that another person has if that question is similar to a previously considered question, do not assume that a prior interpretation will necessarily apply to your situation.
- Your facts may be sufficiently different from those presented in prior interpretations, such that the agency's answer to you might be different from the answer in the prior interpretation letter;
- Your situation may be completely new to the agency and not addressed in an existing interpretation letter;
- The agency's safety standards or regulations may have changed since the prior interpretation letter was written so that the agency's prior interpretation no longer applies; or
- Some combination of the above, or other, factors.
Searching NHTSA’s Online Interpretation Files
Before beginning a search, it’s important to understand how this online search works. Below we provide some examples of searches you can run. In some cases, the search results may include words similar to what you searched because it utilizes a fuzzy search algorithm.
Single word search
Example: car
Result: Any document containing that word.
Multiple word search
Example: car seat requirements
Result: Any document containing any of these words.
Connector word search
Example: car AND seat AND requirements
Result: Any document containing all of these words.
Note: Search operators such as AND or OR must be in all capital letters.
Phrase in double quotes
Example: "headlamp function"
Result: Any document with that phrase.
Conjunctive search
Example: functionally AND minima
Result: Any document with both of those words.
Wildcard
Example: headl*
Result: Any document with a word beginning with those letters (e.g., headlamp, headlight, headlamps).
Example: no*compl*
Result: Any document beginning with the letters “no” followed by the letters “compl” (e.g., noncompliance, non-complying).
Not
Example: headlamp NOT crash
Result: Any document containing the word “headlamp” and not the word “crash.”
Complex searches
You can combine search operators to write more targeted searches.
Note: The database does not currently support phrase searches with wildcards (e.g., “make* inoperative”).
Example: Headl* AND (supplement* OR auxiliary OR impair*)
Result: Any document containing words that are variants of “headlamp” (headlamp, headlights, etc.) and also containing a variant of “supplement” (supplement, supplemental, etc.) or “impair” (impair, impairment, etc.) or the word “auxiliary.”
Search Tool
NHTSA's Interpretation Files Search
Interpretations | Date |
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ID: nht95-2.75OpenTYPE: INTERPRETATION-NHTSA DATE: May 10, 1995 FROM: Vladimir Salita TO: Chief Council, NHTSA TITLE: NONE ATTACHMT: ATTACHED TO 7/2/95 LETTER FROM JOHN WOMACK TO VLADIMIR SALITA (A43; STD. 201; STD. 104; STD. 108; VSA 102); ALSO ATTACHED TO 5/11/95 LETTER FROM JOHN WOMACK TO TERESA THOMPSON; ALSO ATTACHED TO 7/30/95 LETTER FROM JOHN WOMACK TO WAYNE FERGUSON (STD. 108) TEXT: Dear Sir: I am taking the liberty to write you. I have been advised by Mr. Vaniderstine to address to you this letter. Being an electronic engineer I came to some ideas related to improving safety of driving. I hope the inventions I made might be very useful and patentable. My ideas are now in different stages of developement: some of them have been realized in working models, others need futher research and testing. Before taking next step I would like to be sure that my inventions are in accordance with existing stand ards. Also I would very appreciate your opinion on usefulness of the inventions. The brief descriptions of the inventions are enclosed. Thank you for your time and attitude. Enclosure WARNING AND TEACHING DEVISE FOR IMPROVING OF DRIVING HABITS AND FUEL ECONOMY. This is a simple, easy-to-install devise, which is to warn drivers by indicating the excessive deceleration, acceleration and dangerous speed at turns by emitting sound signals. Such warning will teach motor vehicle drivers how to take adequate and s afe actions and to improve fuel economy. This devise can be adjustable for different levels of the controlled parameters or / and be factory-preset to the predetermined values. This inexpensive, dashboard-mounted devise can be powered from separate battery or cigarette lighter and the installation does not require any experience. The working model is available. DECELERATION WARNING LIGHT. The devise measures actual vehicle deceleration and its output controls the frequency of light flashing (preferable high-mounted brake light). This makes following vehicles drivers alert and thus reduces risk of rear-end collisions. The devise proposed is inexpensive, small sized and easy-to-install. There are several patents related to the given invention, which, however, differ from the proposed one those show that the problem is still actual and the solution is very desirable. The working model is available. SELF-ADJUSTABLE WINDSHIELD WIPER. This devise controls the rate of windshield wiper sweeps according to intensity of rain, thus it eliminates the distraction of driver's attention and makes driving more comfortable. This is to improve traffic safety. It needs no additional sensors, such as humidity sensors or windshield transparency sensors. |
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ID: nht95-2.76OpenTYPE: INTERPRETATION-NHTSA DATE: May 11, 1995 FROM: Dennis T. Snyder, Esq. TO: David Coleman -- NHTSA Administrator TITLE: NONE ATTACHMT: ATTACHED TO 6/14/95 LETTER FROM JOHN WOMACK TO DENNIS T. SNYDER (PART 566) TEXT: Dear Mr. Coleman, I have a client engaged in the manufacture of completed heavy duty dump trucks, vans and road tractors. The client obtains chassis-cabs previously produced by an intermediate manufacturer and adds dump bodies, van bodies or fifth wheels. The uniquen ess of the clients business is that the manufacturing work is performed on used chassis-cabs. For example, a chassis-cab which has been used as a road tractor for an indeterminate period may be manufactured into a dump truck by the removal of the fifth wheel and addition of a dump truck body. The question is whether the client is a "final stage manufacturer" within the meaning of the National Traffic and Motor Vehicle Safety Act and, specifically, Parts 566, 567 and 568 of the regulations. (49 CFR 566, 567 and 568.) Stated another way, is the client relieved of an obligation to perform the certifications which would otherwise be required under Parts 567 and 568 because he is performing his manufacturing operations using used chassis-cabs rather than new ones? |
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ID: nht95-2.77OpenTYPE: INTERPRETATION-NHTSA DATE: May 11, 1995 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Scott E. Mack -- Senior Product Manager, Philips Lighting Company ATTACHMT: ATTACHED TO 4/24/95 LETTER FROM SCOTT E. MACK TO CHIEF COUNSEL, NHTSA (OCC 10269) TEXT: Dear Mr. Mack: This is in reply to your letter of April 24, 1995, requesting a confirmation of your interpretation that "Philips Color Clear (TM) Halogen Headlights . . . are in compliance with FMVSS-108." The product in questions "appears to be colored when not in use" but "when lighted it produces white light as defined by J579C." You have provided a report from ETL Testing Laboratories which "indicates that the color of the light is identical to that of a standard halogen headlight." There is no definition of white light in SAE J579c Sealed Beam Headlamp Units for Motor Vehicles, December 1978. We believe you mean SAE J578d Color Specification for Lighting Devices, September 1978 which does contain a definition expressed in chromati city coordinates. The report you supplied indicates that the Philips lamp provides a light within the color coordinates for white when equipped with a red, black, blue, or white insert. As Standard No. 108 contains no requirements for the color of glas s lamp lenses or bulbs, only the light emitted from the lamp, we confirm your conclusion that the Philips Color Clear (TM) headlamp has been designed to conform to the color requirements of Standard No. 108. We appreciated your visit to NHTSA on April 26 to demonstrate the lamp with its various inserts. I understand that the light produced by the lamp, and by a standard headlamp, appeared identical to the naked eye in a side by side comparison. If you have any further questions, you may refer them to Taylor Vinson of this Office (202-366-5263). |
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ID: nht95-2.78OpenTYPE: INTERPRETATION-NHTSA DATE: May 11, 1995 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Teresa Thompson TITLE: NONE ATTACHMT: ATTACHED TO 4/6/95 LETTER FROM TERESA THOMPSON TO NHTSA (OCC 10849) TEXT: Dear Ms. Thompson: We have received your letter of April 6, 1995, with respect to an automotive deceleration signal. You have asked for information "on how to have this product tested and approved as well as information on the legal ramifications and liabilities for the p roduct." The Department of Transportation neither tests nor "approves" products. What it does do is to advise whether motor vehicle equipment is permitted under the statutes and regulations for whose administration it is responsible. In this instance, the appro priate regulation is Federal Motor Vehicle Safety Standard No. 108, Lamps, Reflective Devices and Associated Equipment. This standard specifies requirements for only certain items of lighting equipment but it also has an effect on lighting equipment that is not specified in the standard. That is to say, if an item of lighting equipment is not allowable for a manufacturer or dealer to install as original equipment (i.e., equipment on the vehicle at the time of its original sale), in most cases it won't be allowable in the aftermarket for manufacturer or dealer installation on used vehicles as well. As you describe it, the signal is provided by "a strobe light with an independent power supply, which upon heavy breaking (sic), will activate a strobe for five seconds and on impact for ten minutes." The prototype "is approximately 4" by 3" and may be a ttached to a rear window." Federal laws cover brake activation of your strobe signal. Standard No. 108 requires turn signal lamps, hazard warning signal lamps, and school bus warning lamps to flash. Headlamps and side marker lamps may be flashed for signaling purposes. But all other lamps provided as original equipment must be steady-burning. We regard a strobe lamp as one that flashes. For this reason, the deceleration signal you describe could not be installed as original equipment. Further, its installation on a used veh icle would take the vehicle out of compliance with Standard No. 108. Notwithstanding the discussion above, there is no Federal prohibition on the sale of the strobe signal device, and Federal law does not prevent the vehicle owner from installing it on a used vehicle (however, manufacturers, dealers, distributors, and mot or vehicle repair businesses may not do so), no matter what effect the strobe signal may have upon compliance with Standard No. 108. However, the States have the right to decide whether use of the strobe signal is permissible. We aren't able to provide you with information on State laws, and suggest that you seek an opinion from the American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22303. We can't advise you on your potential liabilities either, and suggest th at you contact your attorney for an opinion on the applicability of local law. In addition, it is important to note that Standard No. 108 prohibits supplementary original lighting equipment that impairs the effectiveness of the original lighting equipment required by Standard No. 108. The proximity of your strobe device in the rea r window to the center highmounted stop lamp required by Standard No. 108 raises the possibility of impairment, especially if the strobe is of a color other than red, or so bright as to mask the center stop lamp signal. I am sorry to be unable to offer you more encouragement at present, as we share your concern with the negative effects of fog and rain on drivers and vehicles. It is obvious that you have given much thought to this problem. Noting that you are testing a prototype, this agency would be interested in receiving any data you have or may develop showing a positive effect of the strobe signal upon the frequency and severity of rear end collisions. You may send this to Michael Perel, Office of Research and D evelopment, NHTSA, Room 6206, 400 Seventh St. SW, Washington, DC 20590. It is conceivable that at some time in the future we would allow the center stop lamp to flash under conditions of rapid deceleration. This could open the way to permissibility of an additional lamp such as yours. I note that, to the extent that your device were only to activate upon impact and not during conditions of rapid deceleration, it would not be prohibited by Standard No. 108. Such a device would be permissible as a supplement to, or substitute for, a ve hicle's hazard warning signal system. We do not know whether it would be permissible under State laws (see discussion above). If you have any further questions, you may refer them to Taylor Vinson of this Office (202-366-5263). |
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ID: nht95-2.79OpenTYPE: INTERPRETATION-NHTSA DATE: May 12, 1995 FROM: K. Howard Sharp -- Attorney at Law, Arnason Law Office TO: John Womack -- Acting Chief Counsel, NHTSA TITLE: NONE ATTACHMT: ATTACHED TO 6/7/95 LETTER FROM JOHN WOMACK TO K. HOWARD SHARP (A43; REDBOOK 2; STD. 108) TEXT: Dear Mr. Womack: Our firm represents NYTAF Industries, Inc. of Edmore, North Darora. NYTAF has developed a device known as Safety Bright(R) which is an auxiliary signalling system for heavy duty vehicles. I have enclosed for your consideration a draft of a brochure NYTAF intends to distribute when it begins to manufacture and market the device. Exhibit A, attached. Additionally, Exhibit B provides an explanation of the product's functions. On May 9, 1995 I spoke to Mr. Taylor Vinson who suggested we request a written opinion from N.H.T.S.A. regarding the applicability of the federal motor vehicle safety standards to Safety Bright(R). Mr. Vinson expressed concern that Safety Bright(R) m ight violate Standard 108 by impairing the effectiveness of required lighting equipment. See 49 C.F.R. @ 571.108 (S 5.1.3). Mr. Vinson declined to offer an opinion, however, since he had not seen the device and knew nothing of it. Consequently, NYTAF now requests a written opinion from N.H.T.S.A. regarding the compliance of Safety Bright(R) with federal motor vehicle safety standards. The attached brochure describes Safety Bright(R) and illustrates the product as it would appear installed on the rear of a semi-trailer. The unit mounts on the rear of the trailer frame directly below the trailer body in the center putting the displa y panel on approximately the same horizontal plane as the tail lights, and brake lights. Safety Bright(R) displays a verbal message appropriate to the particular potential hazard. The red L.E.D. (light emitting diode) panel displays the auxiliary warnings listed in Exhibit B. NYTAF originally designed and manufactured prototype devices with the option of displaying the word "Thanks" but recently decided to delete that message. Safety Bright(R) does not interfere with lighting required by Standard 108. Safety Bright(R) connects to the tractor's power source through the pigtail connection. While certain functions operate in conjunction with existing lighting; such as turn si gnals and brake lights, if the Safety Bright(R) unit were to fail, the existing lamps and signals would continue to operate normally. The L.E.D. display is somewhat more intense than existing brake lights, turn signals and tail lamps. NYTAF believes the greater intensity attracts attention to the vehicle and to the message conveyed by the conventional signals but does not detract f rom the visibility and conspicuity of existing equipment. The greater intensity, while averaging less than one candlepower per L.E.D., enhances Safety Bright's(R) visibility in bright daylight. One might argue that Safety Bright(R) could constitute a distraction and thereby decrease the effectiveness of existing signals and lights required under the regulations, See 49 C.F.R. @ 571.108 (S 5.1.3). We do not agree. To the extent Safety Brigh t(R) might cause such a distraction, it would result only from the product's novelty after its introduction to the market. Safety Bright(R) should create no more of a distraction than reflective tape, retroreflective strips, side marker turn signals, or fuel efficient, aerodynamically designed truck bodies. NYTAF is confident the motoring public would readily accept and undoubtedly benefit from the use of Safety Bright(R) on trucks and semi-trailers. Anecdotal evidence suggests N.H.T.S.A. has considered and rejected a number of somewhat similar products in the past. "Message boards" mounted in car windows and L.E.D. advertising signs mounted on automobiles do create a distraction and a consequent traffic hazard. Safety Bright(R) differs from such devices because it displays only standard traffic related messages. Drivers cannot display their own personal messages or commercial advertising, and they cannot alter the messages programmed into the unit. Therefore, the reasons for rejecting seemingly similar products submitted to N.H.T.S.A. in the past simply do not apply to Safety Bright(R). NYTAF believes Safety Bright(R) fully complies with the federal motor vehicle safety standards. As an enhanced auxiliary signalling device, Safety Bright(R) operates in conjunction with existing, required equipment and furthers the purpose of the app licable standard, which purpose is to reduce traffic accidents and death and injuries resulting from traffic accidents, by . . . enhancing the conspicuity of motor vehicles on the public roads so that, their presence is perceived and their signals understood, both in day light and in dark ness or other conditions of reduced visibility." 49 C.F.R. @ 571.108 (S2). This is exactly the same purpose for which Safety Bright(R) was designed. Ironically, heavy trucks and semi-trailers -- the largest vehicles on our roadways -- have a profound need to increase conspicuity, especially with respect to speed and signals, See generally Exhibit C. Retroreflective strips and reflective tape repr esent recent advances in this area. Nevertheless, the trucking industry along with the general motoring public stand to benefit from an enhanced signalling system for heavy duty vehicles such as semi-trailers. Studies show that most semi-trailer acciden ts occur on city streets at speeds of less than eighteen (18) miles per hour. Exhibit C. Safety Bright(R) offers a special advantage for traffic safety under those circumstances by giving a clear and conspicuous warning to drivers and pedestrians at th e rear of the vehicle of the operator's intended maneuver. At highway speeds, Safety Bright(R) should give other motorists extra reaction time in many instances because of the bright, clearly visible and unambiguous message. Experienced drivers know that even an extra half second of reaction time can sometim es mean the difference between an appropriate response and a tragedy. NYTAF believes Safety Bright(R) would give motorists a more obvious indication of a truck's intended maneuver, thereby alerting other drivers more quickly and decreasing reaction time s. Other messages such as "WIDE LOAD," "LONG LOAD," "BACKING," "CAUTION" and "HELP" draw attention to the special circumstances indicated. The wide or long load messages supplement existing requirements for appropriate markings to increase awareness of the size of the vehicle. The backing signal visually alerts motorists and pedestrians to the truck's directon of motion whereas no regulation currently requires a visual backing signal for semi-trucks. The caution signal works in conjunction with the e mergency flashing signals. The help signal quite obviously is a summons for assistance intended for use by operators of disabled trucks. Attached as Exhibit D are the schematic diagrams of the Safety Bright(R) device and other pertinent electronic date. If you need any additional information, please let us know. The manufacturer will gladly meet with N.H.T.S.A. officials to demonstra te the product and to discuss any aspect of its construction or operation. NYTAF is eager to consider any comments or suggestions for improvement. Thank you for your attention to this request. We look forward to your response. With best regards, I am (Brochure and exhibits omitted.) |
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ID: nht95-2.8OpenTYPE: 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. |
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ID: nht95-2.80OpenTYPE: 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. |
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ID: nht95-2.81OpenTYPE: 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. |
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ID: nht95-2.82OpenTYPE: 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. |
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ID: nht95-2.83OpenTYPE: 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. |
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.