Skip to main content

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 14931 - 14940 of 16514
Interpretations Date
 search results table

ID: nht95-6.45

Open

TYPE: INTERPRETATION-NHTSA

DATE: September 18, 1995

FROM: Ben Ray

TO: John Womack

TITLE: NONE

ATTACHMT: ATTACHED TO 11/28/95 LETTER FROM Samuel J. Dubbin to Ben Ray (A43; Std. 121; Part 571.7)

TEXT: Dear Mr. Womack,

This letter is in regards to brake adjusters for log trailers. I am currently building log trailers for resale. These trailers are used mostly in the woods transporting logs from the woods to the mills. I am using used axles under them. These used axles already have regular brake adjusters on there when I buy them. What I would like is some paperwork saying if this is alright to use these regular brake adjusters instead of automatic adjusters. I was referred to you by Richard Carter, (202-366-5274). Mr. Carter said there was a fine line in regards to which one to use because of the fact that the axles that I use are used. He also said being that the trailer is not considered new, that I could use a regular brake adjuster. I would really appreciate it if you could send me some paperwork stating that it is alright to use these regular brake adjusters. If you should have any questions, please call me at home, 901-925-2727 or work, 901-925-1893.

Sincerely,

ID: nht95-6.46

Open

TYPE: INTERPRETATION-NHTSA

DATE: September 18, 1995

FROM: Alison Vredenburgh -- Vice-president, Research and Development, Error Analysis, Inc.

TO: Kenneth Hardie -- NHTSA

TITLE: NONE

ATTACHMT: 12/8/95 letter from Samuel J. Dubbin to Alison Vredenburgh (A43; Std. 108)

TEXT: I am currently directing a research project pertaining to motorcycle conspicuity. We have developed, and are testing a Motorcycle Conspicuity Enhancement System (MCES). A copy of the paper, which I will present at the Annual Human Factors and Ergonomics Society (HFES) meeting next month, is enclosed.

As a human factors and safety consultants we have been asked to investigate several cases where a lack of motorcycle conspicuity has been a factor in accident causation. The development of the MCES was inspired by these cases. It is designed to attach to the front of motorcycles to enhance visibility using a series of small lights (xenon strobes) that are supplemental to the headlight.

The MCES was built by Dr. Brian Andresen, Director of the Forensic Science Center of Lawrence Livermore National Laboratory. We are are in the early stages of considering patenting the MCES and hope to make it available to motorcycle riders.

In reviewing the laws pertaining to motorcycle lighting, we understand that this system may only be used during daylight hours and may not affect the headlight. If there are any additional regulations pertaining to this system of which we should be aware, please contact me directly at (619) 434-4741.

Enclosure

ENHANCED MOTORCYCLE VISIBILITY THROUGH USE OF MOTORCYCLE CONSPICUITY ENHANCEMENT SYSTEM

(Report omitted)

ID: nht95-6.47

Open

TYPE: INTERPRETATION-NHTSA

DATE: September 19, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: T. J. Sommer -- President, White Bear Sales, Inc.

TITLE: NONE

ATTACHMT: ATTACHED TO 7/28/95 LETTER FROM T. J. SOMMER TO TAYLOR VINSON (OCC 11121)

TEXT: Dear Mr. Sommer:

This is in reply to your FAX of July 28, 1995, to Taylor Vinson of this Office.

You report that Chicago's police department is using four-wheeled all terrain vehicles (ATVs) for patrol work in the downtown area, and that they have been licensed by Illinois for on-road use. You believe that the vehicles are illegal to use on the streets and that city employees are at risk. You have been asked by the director of Chicago's fleet "to compile all federal definitions and statutes which apply to the quad runners, regarding classification, certification, and compliance for street use." You have asked for our assistance.

I note first that while Federal law regulates the manufacture and sale of new motor vehicles, the individual States establish their own requirements for the licensing of motor vehicles. Therefore, the question of whether the ATVs may legally be used on the road is a matter of Illinois law rather than Federal law.

Your letter does, however, raise the issue of whether the manufacture and/or sale of the ATVs was consistent with Federal law. We do not have specific information about the ATVs at issue; however, I can provide general information about how Federal law applies in this area.

By way of background information, Chapter 301 of Title 49 of the U.S. Code authorizes NHTSA to issue safety standards for new motor vehicles and new motor vehicle equipment. All motor vehicles and items of motor vehicle equipment manufactured for sale in the United States must comply with all applicable safety standards set forth in 49 CFR Part 571.

The issue of whether the ATVs were required to comply with the Federal motor vehicle safety standards is dependent on whether they are considered "motor vehicles." I have enclosed several interpretation letters which address the criteria which NHTSA applies in determining whether a vehicle with on and off-road capability is a motor vehicle (addressed to Mr. Matthew Plache, dated December 3, 1991; Mr. Hiroshi Kato, dated October 31, 1988; Mr. Wayne Kirby, dated February 8, 1983; and Mr. Leonard Fink, dated March 25, 1982). If an ATV is a motor vehicle, it must be certified to comply with all applicable safety standards.

If, after reviewing this information, you believe that a violation of Federal law may have occurred, you may wish to contact Mr. Luke Loy of NHTSA's Office of Vehicle Safety Compliance at (202) 366-5288. If you have further questions about the applicability of our standards, please feel free to contact Mr. Taylor Vinson of my staff (202-366-5263).

ID: nht95-6.48

Open

TYPE: INTERPRETATION-NHTSA

DATE: September 19, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Robert J. Ponticelli -- President, American International Pacific Industries Corp.

TITLE: NONE

ATTACHMT: ATTACHED TO 7/25/95 LETTER FROM ROBERT J. PONTICELLI TO JOHN WOMACK (OCC 11082)

TEXT: Dear Mr. Ponticelli:

This responds to your letter asking about how the National Highway Traffic Safety Administration's (NHTSA's) regulations apply to your product. You described your product as an aftermarket anti-theft device that is installed between the steering wheel and the steering shaft. The device is activated by "a key switch" and causes the steering wheel to become freewheeling, thus preventing actual steering of the vehicle. In an August 29, 1995 meeting with NHTSA staff, you demonstrated this device and stated that you also have plans to market it to vehicle manufacturers as original equipment. For the original equipment version of the device, you plan to incorporate a starter interrupt that will prevent the vehicle from starting while the device is in the freewheeling mode. You also requested information on how our regulations apply to regulated parties such as new car dealers and aftermarket service businesses. I will respond to your questions below.

First, I will give you some background information. NHTSA is authorized to issue Federal motor vehicle safety standards (FMVSSs) for new motor vehicles and new items of motor vehicle equipment. The FMVSSs are contained in title 49, part 571 of the Code of Federal Regulations.

NHTSA does not have any specific regulations covering an item of motor vehicle equipment such as your anti-theft device. However, since the steering wheel, steering column, and the area in front of the driver are among the most closely regulated parts of a vehicle, your device could affect a vehicle's compliance with several safety standards.

Because the purpose of your device is to prevent vehicle theft, I will first discuss FMVSS No. 114, the safety standard that deals with theft protection. The pertinent part of Standard No. 114 requires most vehicles to "have a key-locking system which, whenever the key is removed, prevents: (a) the normal activation of the vehicle's engine or motor; and (b) either steering or forward self-mobility of the vehicle or both." Most motor vehicle manufacturers have chosen to comply with this requirement by installing a steering lock. Because a device that causes the steering wheel to become freewheeling prevents actual steering, or maneuvering of the vehicle, it could also be used to meet this requirement. However, to be used as a basis for certification with FMVSS No. 114, the device would have to be activated by removal of the key that controls engine activation.

In addition to possibly being used as a means of complying with FMVSS No. 114, your device could alternatively be operated by a separate key and installed in addition to a steering lock, assuming that it did not affect compliance of the vehicle with that or other safety standards. However, you should evaluate whether the device might pose a safety hazard if used without your planned starter interrupt. A driver who doesn't know (or forgets) about your device could start the vehicle in motion without realizing that the turning of the wheel is not affecting the vehicle.

Other standards that you should be concerned about include FMVSS Nos. 203 (impact protection for the driver from the steering control system), 204 (steering control rearward displacement), and 208 (occupant crash protection). As our engineers explained in our meeting, even small changes to the steering column can affect vehicle compliance with these standards.

Turning to the second part of your question, which legal requirements apply depends on how your product is marketed. If your product is installed by a vehicle manufacturer as original equipment, the vehicle manufacturer would have to certify that the vehicle with your device installed complies with all applicable FMVSS's, including Standard Nos. 114, 203, 204, and 208. If the device is added to a previously certified new motor vehicle prior to its first sale, e.g. by a new car dealer, 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.

If your device is installed on a used vehicle by a commercial business, such as an aftermarket service business or new car dealer, that business would have to make sure that it did not knowingly make inoperative any part of a device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable FMVSS. Any violation of this "make inoperative" prohibition would subject the violator 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, Federal law would not apply in situations where individual vehicle owners installed your device in their own vehicles, even if the 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 States have the authority to regulate modifications that individual vehicle owners may make to their vehicles, so you might wish to consult State regulations to see whether your device would be permitted.

You as the product's manufacturer 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 notifying purchasers of the defective equipment and remedying the problem free of charge.

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." It outlines other laws and regulations that you should be aware of. If you have any further questions about NHTSA's safety standards, please feel free to contact Mr. Paul Atelsek at this address or by telephone at (202) 366-2992.

ID: nht95-6.49

Open

TYPE: INTERPRETATION-NHTSA

DATE: September 19, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Milford R. Bennett -- Director, Safety Affairs and Safety & Restraints Center, General Motors Corporation

TITLE: NONE

ATTACHMT: ATTACHED TO 5/19/95 LETTER FROM MILFORD BENNETT (SIGNED BY F. LAUX) TO JOHN WOMACK

TEXT: Dear Mr. Bennett:

This responds to General Motors' (GM's) May 19, 1995 letter asking whether a sunshade device is permitted under the 70 percent light transmissibility requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 205, Glazing Materials. You describe the device as a screen-like device that is stowed in the back panel shelf area below the rear window and that can be electrically raised and lowered by a driver operated switch. The light transmissibility through the combination of the rear window and the raised sunshade is less than 70 percent. The short answer to your question is that the device is permitted.

Although you note earlier agency interpretations stating that windows with sunshades must still comply with Standard No. 205, you believe that the standard does not apply to your device. You state that those interpretations were distinguishable because the other shading devices were attached to the window, while your device is not.

You are correct in your assertion that installation of your sunshade would not cause a noncompliance with Standard No. 205. The purpose of the 70 percent light transmissibility requirements in Standard No. 205 is to ensure that the driver can see 70 percent of the incident light through the windows that are requisite for driving visibility, under all conditions of lighting. However, the test procedures do not incorporate an in-vehicle test. Instead, they contemplate testing only the glazing itself. Your mesh screen sunshade need not comply with the standard (because it does not meet the definition of glazing) or in combination with the rear window (because it is not attached).

Although our standards do not prohibit this device, we have some safety-related concerns with its use in inappropriate situations. NHTSA hopes that GM plans to take steps to minimize the likelihood that the sunshade will be raised in such situations.

I hope this information is helpful. If you have any further questions, please feel free to contact Paul Atelsek of my staff at this address or by telephone at (202) 366-2992.

ID: nht95-6.5

Open

TYPE: INTERPRETATION-NHTSA

DATE: August 8, 1995

FROM: Eric D. Swanger, PE -- Engineering Manager, Specialty Manufacturing Co.

TO: John Womack -- NHTSA

ATTACHMT: ATTACHED TO 11/21/95 LETTER FROM Samuel J. Dubbin to Eric D. Swanger (A43; Std. 131)

TEXT: Dear Mr. Womack:

Research is performed at Specialty Manufacturing on a continual basis to investigate different means of improving upon the safety of school bus equipment. Recently, an inquiry has been made to Specialty concerning the usage of light-emitting diodes (LED's) on stop arms. Apparently one state feels the usage of LED's to spell out the word "STOP" on the stop arm blade would increase the visibility of the sign in certain weather conditions.

After the engineering department of Specialty Manufacturing manufactured a prototype unit and tested the unit, several questions were raised which we feel need clarification from NHTSA in reference to FMVSS 131. The first being the basic viewing angles of LED's. While LED's have a quicker "on" and "off" time than incandescent bulbs, the overall viewing angle of an LED is extremely limited. Depending upon the placement of the LED's in the stop arm blade, the word "STOP" can vary from being noticeable to being a scattered pattern of lights. Exact placement of the LED's will depend upon the consistency of the manufacturing process. With incandescent lights, the light is very noticeable from all angles and manufacturing consistencies are not at all a concern.

The second issue is the legibility of the LED "STOP" at any given distance. Opinions of many casual onlookers asked to critique the LED sign when lit, seem to indicate that the letters are not large enough nor spaced far enough apart to be discernible at larger distances. Since the size of the letters is clearly defined by FMVSS 131, it appears that standard may have to be revised in order to ensure that "STOP" is legible at greater distances.

P2

The third issue is that of safety equipment consistency. Currently, all stop arms must have the word "STOP" displayed on the stop sign itself. The red lights are optional. The addition of another optional method of lighting may lead to confusion and subsequent passing violations due to visiting drivers being unfamiliar with state or county practices of school bus identification.

The development of an LED stop arm appears to our company to be quite expensive at the out set, and we are definitely concerned with the viewing angle, legibility from certain distances, and that consistences provided by FMVSS 131 could be in jeopardy.

I'm asking if you would please give us your interpretation of FMVSS 131 and the use of LED lights outlining the word "STOP." Specialty Manufacturing would be available to help in any standard research, manufacturer input, etc., as we have done in the past.

If I may be of any assistance, please do not hesitate to call me at 1-800-951-7867.

ID: nht95-6.50

Open

TYPE: INTERPRETATION-NHTSA

DATE: September 19, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: David Seagren -- Dealer Principal, Pony Express Dodge, Inc.

TITLE: NONE

ATTACHMT: 12/8/95 letter from Samuel J. Dubbin to Peter F. Marthy (A43; Part 580)

TEXT: This is in response to your letter sent to this office by telefax on September 12, 1995. In your letter, you ask whether it is permissible to alter an odometer that registers kilometers rather than miles by multiplying the kilometer reading by .62, when there had been a previous attempt to convert the reading to miles. Your letter states that the earlier attempt resulted in the odometer being set back to the equivalent in miles but the odometer continued to register distance in kilometers.

As you are aware from a Federal Register notice faxed to you by Eileen Leahy of this office, the National Highway Traffic Safety Administration (NHTSA), the Federal agency with responsibility for the odometer disclosure regulations promulgated pursuant to the Truth in Mileage Act of 1986 (TIMA) has stated that it is permissible to reset the odometer from kilometers to miles by multiplying the number of kilometers shown on the odometer by .62, and that it is also permissible to certify that number of miles as "actual" when completing the odometer disclosure statement when ownership of the vehicle is transferred.

The rationale for this policy is that "mileage" is defined in the Federal regulations as distance traveled, and it is permissible to express the number either in miles or metrically if it is known that it reflects the actual distance traveled and that the disclosure of the odometer reading specifies which system of measure (miles or kilometers) is being used. Because the conversion from kilometers to miles can be accurately made simply by multiplying the kilometers on the odometer by 0.62, the agency believes that there is little likelihood that permitting odometer readings that have been converted from kilometers to miles to be recorded as "actual mileage" will result in an inaccurate or misleading representation of the distance a vehicle has traveled.

The situation you describe is more complicated because a previous owner of the vehicle in question had already set back the odometer to the mileage equivalent after purchasing it with an odometer reading in kilometers, but according to your letter did not execute properly the procedure necessary to make the odometer register miles rather than kilometers while being driven. The result of this error has been the addition of kilometers to a figure that reflected miles rather than kilometers traveled.

In order to permit recording of a conversion of the present odometer reading from kilometers to mileage as "actual mileage" in this circumstances, two criteria must be satisfied. First, it must be apparent that the calculation at the time of the first conversion was done properly so that it reflects the actual number of miles the vehicle had traveled at that time. From the documents you submitted reflecting the events that occurred prior to your purchase of the vehicle, it appears that the previous owner properly converted kilometers to miles. Accordingly, the first criterion is satisfied.

It is then necessary to establish that the reading now shown on the odometer accurately represents the distance traveled by the vehicle since the first attempted conversion. There is no indication in any of the documentation you furnished that there have been any intervening alterations to the odometer or changes in the way it has recorded distance that would alter the accuracy of its current reading. In addition, you state that since your company has owned the vehicle, the odometer has consistently operated in a way that shows that it was registering kilometers rather than miles. Based on these factors, it appears that it will be possible for you to ascertain with accuracy the distance the vehicle has traveled since the first conversion from kilometers to miles was made.

The proper way to do this conversion is to subtract the number shown as the reading in miles as a result of the calculation made at the time conversion was first attempted, from the number showing on the odometer when you transfer ownership of the vehicle. The result will be the total kilometers the vehicle has traveled since that time. To arrive at the number of miles traveled since the attempted conversion, the result of that subtraction is to be multiplied by 0.62 as described above. In turn, the number resulting from that multiplication is added to the number of miles at the time of the first conversion and the sum is the total number of miles traveled by the vehicle at the time of transfer. You may then properly certify on the odometer disclosure statement when you transfer ownership of the vehicle that that number is its actual mileage.

Because the Kansas Motor Vehicle Department asked that you contact this office for our interpretation of the proper way to handle the sale of this vehicle under the Federal odometer disclosure regulations, it would be advisable to provide that office with a copy of this letter either before or at the time of your application for a new title.

I hope this information is helpful. If you have any further questions about this matter, please contact Eileen Leahy, an attorney in this office, at the address shown above or at (202)366-5263.

(9/12/95 telefax from David Seagren to NHTSA is not available.)

ID: nht95-6.51

Open

TYPE: INTERPRETATION-NHTSA

DATE: September 20, 1995

FROM: Jonathan P. Reynolds -- Executive Vice President, General Counsel, Cosco

TO: Deirdre Fujita -- NHTSA

TITLE: Cosco's Petition for Reconsideration Final Rule - Federal Register Volume 60 Number 129 Docket No. 74-09; Notice 42

ATTACHMT: ATTACHED TO 10/24/95 LETTER FROM JOHN WOMACK TO JONATHAN P. REYNOLDS (REDBOOK 4; PART 553; 74-09, N42-005-02)

TEXT: Dear Ms. Fujita:

In accordance with the requirements set forth in the Federal Register announcement of the subject Final Rule, Cosco submitted its petition for reconsideration in a timely fashion. The petition was transmitted via Federal Express on Friday, August 4, 1995, for next day delivery, on Monday, August 7, 1995.

Although we have not been formally advised, we have learned informally that NHTSA may contend that the petition was not received until August 10. We have confirmed with Federal Express that in fact the petition was delivered on August 7, 1995, and signed for by NHTSA employee T. Proctor. Attached are the Federal Express forms signed by each recipient of a Federal Express delivery, showing T. Proctor under item 15 on page 2 for August 7, 1995. Federal Express has confirmed that this package was in fact delivered to NHTSA on August 7, 1995.

Please confirm in writing that Cosco's petition is being deemed as timely received and that a response to the petition will be forthcoming in a timely fashion. Given the scope of the Final Rule and the very important concerns involved, Cosco assumes that the agency wishes to promptly address the issues raised by Cosco in its petition.

Please contact me if you require any further information or have any questions. I look forward to your prompt reply to this inquire.

(Federal Express forms omitted.)

ID: nht95-6.52

Open

TYPE: INTERPRETATION-NHTSA

DATE: September 20, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Mr. Yoshiaki Matsui -- Manager, Automotive Equipment, Legal & Homologation Section, Stanley Electric Co., Ltd.

TITLE: Re: Headlamp System Containing Fog Lamp

ATTACHMT: ATTACHED TO 8/11/95 LETTER FROM YOSHIAKI MATSUI TO CHIEF COUNSEL, NHTSA

TEXT: Dear Mr. Matsui:

This replies to your letter of August 11, 1995, with reference to possible headlamp systems that produce a fog lamp beam, as well as upper and lower beams. According to your letter, "the fog lamp is reciprocally incorporated with the high beam headlamp, using one dual-filament bulb (ex.; HB2). The high beam and the fog lamp will not be lit simultaneously." You refer to paragraph S5.1.3 of Federal Motor Vehicle Safety Standard No. 108 and conclude that "such a combination will not impair the effectiveness of the headlamp."

We agree, with respect to the headlamp itself, that a fog lamp operating simultaneously with the lower beam will not impair the effectiveness of the lower beam's photometrics and ability to illuminate the roadway. We view this as a supplement to the lower beam. However, under S5.1.3, the question is whether the fog lamp, either operating alone or when the lower beam headlamp is activated, will impair the effectiveness of any front lighting equipment that is required by Standard No. 108. The responsibility for the determination of compliance with S5.1.3 is not Stanley's, but that of the manufacturer of the vehicle in which the combination headlamp is installed, who must certify that its vehicle meets all applicable U.S. Federal motor vehicle safety standards.

The other front lighting equipment required by Standard No. 108 consists of parking lamps and turn signal lamps. The amber parking lamps serve to mark a vehicle, a function incidentally served by white fog lamps. Thus we do not believe that the Stanley headlamp would impair the effectiveness of parking lamps in any position in which the headlamp may be installed on the front of a vehicle.

The situation differs with respect to turn signal lamps. A vehicle manufacturer must take care to ensure that a vehicle on which the combination headlamp is installed conforms to the requirements of Standard No. 108 and to paragraph 5.1.5.4 of SAE Standards J588 NOV84 or J1395 APR85, the two turn signal standards incorporated by reference in Standard No. 108. Paragraph 5.1.5.4 treats the relationship between luminous intensity and photometrics "where the front turn signal is mounted in close proximity to the low beam headlamp or any additional lamp used to supplement or used in lieu of the low beam, such as an auxiliary low beam or fog lamp." It does this by establishing luminous intensity multipliers based upon the distance that separates the lamps. For example, if the space between the front turn signal and the lighted edge of the fog lamp is 75 mm to less than 100 mm, the photometric requirements for a front turn signal lamp are 1.5 times more than those required when the spacing is 100 mm or more (Paragraph S5.3.1.7 of Standard No. 108 requires the multiplier at this distance to be 2.5 when the lamp is a lower beam headlamp rather than a fog lamp).

Finally, as a cautionary note, we believe that Stanley should evaluate the glare potential of the headlamp when the fog lamp and lower beam are operating simultaneously, as it is important to safety that oncoming drivers not be distracted or discomforted in the operation of their vehicles.

If you have any further questions, you may refer them to Taylor Vinson of this Office (phone: 202-366-5263).

ID: nht95-6.53

Open

TYPE: INTERPRETATION-NHTSA

DATE: September 20, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Dennis G. Moore -- President, Sierra Products, Inc.

TITLE: NONE

ATTACHMT: ATTACHED TO 7/31/95 LETTER FROM DENNIS G. MOORE TO NHTSA CHIEF COUNCIL

TEXT: Dear Mr. Moore:

This responds to your letter of July 31, 1995, with respect to lens area requirements of amber turn signal lenses.

You believe that "by reducing the minimal area of the Amber Turn Signal light lens from 12 square inches to approximately 8 square inches or 6 square inches the U.S. would have more practical rules for U.S. Exports at no expense to Safety. You ask that, "If NHTSA's Legal Council feels this error should be corrected through the Petitioning Process, I ask that this writing be considered a 'Petition for Change of FMVSS # 108 Request'".

Standard No. 108 contains two relevant regulations, one applicable to vehicles whose overall width is less than 80 inches, and one to those whose overall width is 80 inches or more.

Under paragraph S5.1.1.26(a), the functional lighted lens area of a single turn signal lamp of either red or amber on a vehicle whose overall width is less than 80 inches shall be not less than 50 square centimeters. This is approximately 8 square inches. Therefore, no rulemaking is required to implement your recommendation.

The standard that applies to turn signal lamps on vehicles whose overall width is 80 inches or more is SAE Standard J1395 APR85, incorporated by reference in Standard No. 108. Under its paragraph 5.3.2, the functional lighted lens area of a single turn signal lamp shall be at least 75 square centimeters, or approximately 12 square inches. Therefore, rulemaking is required to implement your recommendation.

We are transmitting your letter to our Office of Safety Performance Standards for consideration as a petition for rulemaking to change the minimum lens area requirement for turn signal lamps on large vehicles from 75 to 50 square centimeters. On September 4, 1995, I determined that your letter met our procedural requirements for a petition. Accordingly, the Office of Safety Performance Standards will inform you not later than January 1, 1996, whether your petition has been granted.

If you have any questions, you may refer them to Taylor Vinson of this Office (202-366-5263).

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.