ID: nht93-6.29

DATE: September 2, 1993

FROM: Donald W. Vierimaa -- Vice President-Engineering, Truck Trailer Manufacturers Association

TO: John Womack -- Acting Chief Counsel, NHTSA

COPYEE: TTMA Engineering Committee; Tank Conference Engineering Committee; The 3M Company; Reflexite

TITLE: Conspicuity

ATTACHMT: Attached to letter dated 2/7/94 from John Womack to Donald W. Vierimaa (A42; Std. 108)

TEXT:

We request three interpretations pertaining to S5.7 of FMVSS 108.

Conversion from S1 to English linear dimensions

May we consider the following nominal English dimensions equivalent for the purpose of compliance with S5.7 of FMVSS 108?

FMVSS 108 English English Citation Item Metric (actual**) (nominal)

5.7.1.3(b) Length of 300 mm 11.8 inches 12 inches red or white +/- 150 mm +/- 5.9 inches +/- 6 inches block of (150 mm (5.9 inches (6 inches sheeting to 450 mm) to 17.7 in.) to 18 inches)

5.7.1.3(d) Width of Grade 50 mm min* 1.9 inches 2 inches DOT C2 sheeting

5.7.1.3(d) Width of Grade 75 mm min* 2.9 inches 3 inches DOT C3 sheeting

5.7.1.3(d) Width of Grade 100 mm min* 3.9 inches 4 inches DOT C4 sheeting

5.7.1.4(b) Edge of white 75 mm min. 2.9 inches 3 inches sheeting to any lamp

5.7.1.4(c) Edge of red 75 mm min. 2.9 inches 3 inches sheeting to an amber lamp

5.7.1.4.1(a) Height of 1.25 m 49.2 inches 49 inches horizontal sheeting on rear

5.7.1.4.1(b) Length of 300 mm min* 11.8 inches 12 inches sheeting in upper contours of trailer

5.7.1.4.2(a) Height of 1.25 m 49.2 inches 49 inches horizontal sheeting on side of trailer

5.7.1.4.2(b) Alternative 25 mm min* 0.98 inches 1 inch width of two strips of Grade DOT C2 sheeting and their separation 25 mm max 0.98 inches 1 inch

5.7.1.5 Sheeting 3 mm min 0.118 inches 1/8 (0.125) certification inch character height

5.7.1.5 Sheeting 300 mm max 11.8 inches 12 inches certification marking separation

5.7.2.2(b) Alternative 100 mm max 3.9 inches 4 inches reflex reflector center to center separation

5.7.2.3 Reflex 3 mm min 0.118 inches 1/8 (0.125) reflector inch certification character height

* Assumed to be minimum. ** Significant decimal places for comparison.

The nominal English dimensions without underlining would appear to be acceptable conversions since they exceed the minimum metric dimensions. The nominal English dimensions underlined would, however, exceed the metric maximum dimension.

SAE J1322 JUN85, "Preferred Conversion Values for Dimensions in Lighting - Inch-Pound Units/S1," describes how English units may be converted to S1 (metric) units, but does not describe how to convert S1 units to English Units.

Vertical Location of Rear and Side Sheeting Cargo tank trailers may have a "vertical" surface only at their "belt line" which may be as high as 90 inches (2.3 m) above the ground. Retroreflective sheeting could, however, be located much closer to the ground, but for some

cargo tank trailers this may place the sheeting on non-vertical surfaces. In our comment of March 31, 1992 to Docket No. 80-9; Notice 4 we stated that "it is not clear from the proposed rulemaking as to where retroreflective material should be placed on curved surfaces of tank and some dump trailers or angled surfaces of some dump trailers."

One manufacturer of retroreflective sheeting states that "the sheeting could be applied at a maximum angle of 30 degrees to the vertical." This manufacturer reports that "An angle greater than this provides less conspicuity as defined by NHTSA."

May retroreflective sheeting be located significantly higher than 1.25 m above the road surface if there is no vertical surface lower than this height without installing structure just for the sheeting?

Upper Contour Sheeting

May the horizontal and vertical sheeting to the right and left upper contours of the trailer body required per S5.7.1.4.1(b) be of the dimensions and location shown in the enclosed figures 1 through 5?

Since a number of trailer manufacturers are presently installing conspicuity treatments in accordance with S5.7 of FMVSS 108 as standard equipment or at the request of their customers, your timely response is desirable.

ID: nht94-2.4

TYPE: Interpretation-NHTSA

DATE: March 29, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Harry C. Gough, P.E. -- Automotive Engineering Professional Specialist, State of Connecticut, Department of Motor Vehicles

TITLE: None

ATTACHMT: Attached to letter dated 12/2/93 from Harry C. Gough to NHTSA Chief Counsel (OCC 9398)

TEXT:

This is in reply to your letter of December 2, 1993, with respect to the term "alternately flashing" as it applies under Safety Standard No. 108 to school bus lamps. You ask for our opinion because a manufacturer of strobe lighting has supplied document ation indicating that the system complies with Standard No. 108.

According to your letter, in this system, the lamp on one side of the school bus (front and rear) "flashes on and off four times in a 255 millisecond period and then stays off for 745 milliseconds, then the lamp on the opposite side of the bus repeats th e aforementioned pattern." You inquire as to whether "alternately flashing" refers to this pattern, "or do the four distinct on/off cycles on each side of the school bus defeat the intent of the term alternating."

As you know, paragraph S5.1.4 of Standard No. 108 incorporates by reference SAE Standard J887, School Bus Red Signal Lamps, July 1964, which requires that school bus warning lamp systems "flash alternately." We believe that the light emanating from a st robe lamp that flashes four times in 0.255 second will be perceived as a single flash of varying intensity and not as four separate flashes, and that when this is followed by an identical pattern on the other side of the bus, the system is one that is al ternately flashing within the meaning of Standard No. 108.

Further, under this interpretation, the flash rate meets SAE J887's specification of 60-120 flashes a minute. Unlike other SAE materials incorporated by reference relating to signal lamps (e.g., J1133 School Bus Stop Arms in Standard No. 131 School Bus Pedestrian Safety Devices and J590b Automotive Turn Signal Flashers in Standard No. 108), J887 contains no "percent current 'on' time" requirements.

I hope that this answers your question.

ID: nht94-7.14

DATE: March 29, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Harry C. Gough, P.E. -- Automotive Engineering Professional Specialist, State of Connecticut, Department of Motor Vehicles

TITLE: None

ATTACHMT: Attached to letter dated 12/2/93 from Harry C. Gough to NHTSA Chief Counsel (OCC 9398)

TEXT:

This is in reply to your letter of December 2, 1993, with respect to the term "alternately flashing" as it applies under Safety Standard No. 108 to school bus lamps. You ask for our opinion because a manufacturer of strobe lighting has supplied documentation indicating that the system complies with Standard No. 108.

According to your letter, in this system, the lamp on one side of the school bus (front and rear) "flashes on and off four times in a 255 millisecond period and then stays off for 745 milliseconds, then the lamp on the opposite side of the bus repeats the aforementioned pattern." You inquire as to whether "alternately flashing" refers to this pattern, "or do the four distinct on/off cycles on each side of the school bus defeat the intent of the term alternating."

As you know, paragraph S5.1.4 of Standard No. 108 incorporates by reference SAE Standard J887, School Bus Red Signal Lamps, July 1964, which requires that school bus warning lamp systems "flash alternately." We believe that the light emanating from a strobe lamp that flashes four times in 0.255 second will be perceived as a single flash of varying intensity and not as four separate flashes, and that when this is followed by an identical pattern on the other side of the bus, the system is one that is alternately flashing within the meaning of Standard No. 108.

Further, under this interpretation, the flash rate meets SAE J887's specification of 60-120 flashes a minute. Unlike other SAE materials incorporated by reference relating to signal lamps (e.g., J1133 School Bus Stop Arms in Standard No. 131 School Bus Pedestrian Safety Devices and J590b Automotive Turn Signal Flashers in Standard No. 108), J887 contains no "percent current 'on' time" requirements.

I hope that this answers your question.

ID: nht71-3.10

DATE: 05/27/71

FROM: AUTHOR UNAVAILABLE; R. L. Carter; NHTSA

TO: Ideal Corporation

TITLE: FMVSS INTERPRETATION

TEXT: In your letter of May 4, 1971, to Francis Armstrong you request permission to conduct testing of turn signal and hazard warning signal flashers pursuant to SAE Standard J823b, "Flasher Test Equipment," April 1963.

Federal Motor Vehicle Safety Standard No. 108 incorporates by reference SAE Standard J590b, "Automotive Turn Signal Flashers," October 1965, and SAE Recommended Practice J945, "Vehicular Hazard Warning Signal Flasher," February 1966, both of which specify test circuitry and equipment according to "SAE J823." It is my understanding that the major difference between J823 and J823b, which becomes the appropriate sub-referenced standard on January 1, 1972, is the specification in the latter that "The required voltage tests [for variable-load flashers] with maximum bulb load shall be conducted without readjusting each corresponding power supply voltage, previously set with minimum bulb load." It appears that J823 was written before variable load flashers were in general use and that this is the reason for omission of this specification from J823. Since J823b includes all the requirements of the presently referenced SAE standard, you may proceed to implement it immediately.

ID: 2041o

T.P. Bailey, Legislation Engineer
International Automotive Design
I.A.D. House
Dominion Way
Worthing, Sussex BN14 8LU England

Dear Mr. Bailey:

This responds to your letter of June 10, 1988, in which you asked for an interpretation of Standard No. 104, Windshield Wiping and Washing Systems (49 CFR 571.104). More specifically, you asked two questions about the requirements set forth in section S4.1.2, Wiped area, of Standard No. 104.

You first asked whether section S4.1.2 of Standard No. 104 applies only to passenger cars. The answer to this question is yes. Section S4.1.2 reads as follows: "When tested in accordance with SAE Recommended Practice J903a, May 1966, each passenger car windshield shall ..." (emphasis added). The underlined language explicitly limits the requirements to passenger car windshields. Hence, the windshields on other vehicle types are not subject to the requirements of S4.1.2.

Your second question involved the dimensions of "Area A" used to determine whether a car complies with the wiped area requirements in section S4.1.2. Section S4.1.2.1 of Standard No. 104 specifies that the dimensions for "Area A" are established as shown in SAE Recommended Practice J903a, May 1966, and specifies that at least 80 percent of "Area A" must be wiped. Following the procedures set forth in the SAE Recommended Practice, you noted that "Area A" on a hypothetical vehicle would extend to the daylight opening area on one side of the windshield and extend beyond the daylight opening area on the other side of the windshield. When calculating the percentage of Area A that is wiped, your letter sets forth four different possible dimensions for Area A and asks which is used to determine whether the vehicle wipes at least 80 percent of Area A. Again section S4.1.2 explicitly answers this question. That section specifies that each passenger car windshield shall wipe 80 percent of Area A that "is within the area bounded by a perimeter line on the glazing surface 1 inch from the daylight opening."

Please let me know if you have any further questions or need any additional information.

Sincerely,

Erika Z. Jones Chief Counsel

/ref:104 d:ll/3/88

ID: 23729.ztv

Mr. Kevin Thies
26713 138^th Place, SE
Kent, WA 98042-8056

Dear Mr. Thies:

This is in reply to your letter of October 4, 2001, asking for an interpretation of Federal Motor Vehicle Safety Standard No. 108. We regret the delay in responding to you.

You quoted S5.5.4 which states in pertinent part "The stop lamps on each vehicle shall be activated upon application of the service brakes." You report that the stop lamps on your vehicle "will turn on upon initial application of the service brakes." However, "as I come to a stop, I let up a little bit on the brake pedal for a smooth stop. When I let up that little bit of pedal pressure, the brake lights turn off even though the service brakes are still applied." You ask whether your vehicles performance complies with S5.5.4.

Without conducting specified compliance testing, we do not have an opinion on the behavior of your particular vehicle. Manufacturers are required in good faith to certify that their vehicles meet all applicable Federal motor vehicle safety standards. We will, however, comment on the general question of whether stop lamps may be deactivated while the service brakes are applied.

Standard No. 108 requires, as you have noted, that the stop lamps be activated upon application of the service brakes. We have also stated that implicit in the requirement that stop lamps be activated upon application of the service brakes is the requirement that they must be deactivated when the service brakes are not applied (letters of June 3, 1991 to Norman H. Dankert and of September 22, 1997, to Senator Phil Gramm, copies enclosed).

In interpreting S5.5.4, a distinction must be made between depression of the brake pedal by a driver and application of the service brakes. In a letter of May 8, 1991, to John E. Calow (copy enclosed), we observed that when a brake pedal is depressed, there may be a small amount of "free play" before the service brake begins to apply. We went on to say that we would consider lamp activation required "as soon as any measurable brake torque occurs." Consistent with this opinion, we would say that stop lamps should remain activated whenever any measurable brake torque exists.

Sincerely,
Jacqueline Glassman
Chief Counsel
Enclosures
ref:108
d.6/10/02

ID: 19337.ztv

Mr. Bill Carpenter, Jr.
The Carpenter Group, USA
514 Chestnut Street
Pacific Grove, CA 93950-3916

Dear Mr. Carpenter:

This is in reply to your recent letter to Taylor Vinson of this Office, asking for a clarification of our letter to you dated November 20, 1998.

With reference to the security device as described in your letter to us of August 3, 1998, we informed you that "The manufacture and sale of this accessory is not subject to any Federal motor vehicle safety standard." We continued by cautioning that its installation had a "theoretical potential of affecting compliance" with Safety Standard No. 111, the Federal rearview mirror standard. You wish us to restate our advice to read "The manufacture, sale, and use of the Auto Tracker (TM) Security Beacon does not violate any current U.S. Federal motor vehicle safety standard." The purpose of your request is "so that the National Highway Traffic Safety Administration review of the product can be stated in a concise, direct, and easily understandable manner for the general public."

We cannot furnish the interpretation you seek. You have gone beyond our letter in asking us to state that the "use" of the product is not subject to any Federal motor vehicle safety standard, when our letter clearly indicated that installation of the product had the potential of affecting compliance with Standard No. 111.

I am sorry you feel that we have not stated our views "in a concise, direct, and easily understandable manner for the general public." However, our opinion was directed to you, a manufacturer who sought to understand the relationship of your product to applicable Federal requirements, and was not intended to facilitate its advertising. If you wish to use our letter for such purpose, we have no objection to your stating, as we did in

our letter of November 20, that "The manufacture and sale of this accessory is not subject to any Federal motor vehicle safety standard."

Sincerely,
Frank Seales, Jr.
Chief Counsel
ref:108#111
d.1/28/98

ID: GF003171

Mr. Timothy C. Murphy
Vice President, Engineering
Peterson Manufacturing Company
4200 East 135^th Street
Grandview, MO 64030-2896

Dear Mr. Murphy:

This responds to your April 8, 2005, letter asking about clearance lamp location requirements for trailers equipped with outboard fenders.

Your letter and accompanying diagrams show a dual axle trailer equipped with outboard fenders each extending approximately 10 inches from the main body of the trailer. The outer edges of the fenders are the widest part of the trailer. Specifically, the main body of the trailer measures 81 inches, and the distance between the outer edges of the trailer measured at the fenders is 102 inches. You intend to install both front and rear clearance lamps on the top of each fender, instead of on the main body of the trailer. You ask whether this is permissible under Federal Motor Vehicle Safety Standard (FMVSS) No. 108, Lamps, Reflective Devices and Associated Equipment.

Table II of FMVSS No. 108 specifies that for a trailer with an overall width of 80 inches or more, the front and rear clearance lamps must be located "to indicate the overall width of the vehicle . . . and as near the top thereof as practicable."

As explained in our March 4, 1996, letter to Mr. Jerry Clay, when the widest part of a trailer is the outer edge of the fender, locating the front and rear clearance lamps on the fender satisfies the requirements of FMVSS No. 108 because the lamps would indicate the overall width of the trailer (see also, our September 4 letter to John W. Cook). By contrast, locating the clearance lamps on the main body of the trailer would not adequately indicate the overall width of the vehicle.

If you need further assistance, please contact George Feygin of my staff at this address or at (202) 366-2992.

Sincerely,

Jacqueline Glassman
Chief Counsel

NCC-112:Gfeygin:mar:5/13/05:62992:OCC 003171
Cc: NCC-110 Subj/Chron, Redbook (2), interp 108
U:\NCC20\INTERP\108\GF003171.doc

ID: nht95-4.48

TYPE: INTERPRETATION-NHTSA

DATE: October 9, 1995

FROM: Samuel J. Dubbin -- Chief Counsel, NHTSA

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

TITLE: Accessory Lamp with LEDs

ATTACHMT: Attached to 9/18/95 letter from Yoshiaki Matsui to NHTSA Chief Counsel

TEXT: Dear Mr. Matsui:

This responds to your letter of September 18, 1995, describing a combination tail, stop, and rear turn signal lamp which incorporates incandescent bulbs to perform assigned functions, and which contains light-emitting diodes (LEDs) in a compartment along the outboard side.

With respect to red LEDs adjacent to the tail and stop lamp, you state that the lamp is designed to conform to Standard No. 108 using the incandescent bulbs only, and that your regard the LEDs as an "accessory" acceptable to NHTSA (Your Question 1).

We agree. Because the LEDs are not necessary to conformance with Standard No. 108, they are considered supplemental lighting equipment. Such equipment is permitted by paragraph S5.1.3 of Standard No. 108 if it does not impair the effectiveness of light ing equipment required by Standard No. 108. You state that when the taillamp and LEDs are lit simultaneously, the total intensity does not exceed the maximum intensity specified for a one-section taillamp. It would therefore appear that the presence of the LEDs does not impair the effectiveness of the taillamp (or the stop lamp, which will have a higher intensity).

The red LEDs will provide a red color through the amber lens that covers the turn signal lamp, and will remain on when the turn signal is activated (Your Question 2). This design also appears permissible. We have never considered contiguous rear steady -burning red and flashing amber lamps to be prohibited by Standard No. 108 (the basic design of your lamp), and we do not believe that the supplemental red LEDs will impair the effectiveness of the amber turn signal lamp.

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

ID: 21325windshieldrepairneb

Mr. David Harner
Novus Windshield Repair
35 Division Street
Danbury, CT 06810

Dear Mr. Harner:

Your March 15, 2000, letter regarding windshield repair was referred to my office for reply.

You state that you were told by your franchiser that the United States Department of Transportation (DOT) attempted to regulate the windshield repair business about ten years ago and that DOT eventually passed only one regulation with regards to windshield repair that required "'all damage must have a drying process performed on the damaged area prior to repairing the damaged area' (or something to this effect)." You ask for a "confirmation" of the existence, or lack thereof, of such a regulation.

Our statute, 49 U.S.C. 30101 et seq., as amended (the Act), authorizes the National Highway Traffic Safety Administration to issue Federal motor vehicle safety standards (FMVSS) applicable to new motor vehicles and new items of motor vehicle equipment. Glazing repair businesses, sellers of vehicles or automotive glazing, and manufacturers of glazing repair kits all have different responsibilities and liabilities regarding automotive glazing under the Act. These are described in a September 3, 1981, letter to National Glass Dealers Association, a copy of which is enclosed. FMVSS 205, Glazing Materials (copy enclosed), which establishes performance requirements for automotive glazing, has remained unchanged for many years and does not mention any type of "drying process."

Your franchiser may be referring to a law administered by the Department's Federal Motor Carrier Safety Administration, which has jurisdiction over interstate motor carriers operating in the U.S. You can contact Mr. Larry Minor, Division Chief, Vehicle and Roadside Operations, in that office at (202) 366-4012, for information about any requirements that may apply to your product. In addition, states have the authority to regulate the use and licensing of vehicles operating within their jurisdictions. You should therefore check with your State Department of Motor Vehicles to find out about any activity in this area.

Sincerely,
Frank Seales, Jr.
Chief Counsel
Enclosures
ref:205
d.6/30/2000