ID: aiam5503

"Dear Mr. Gough: This responds to your letter to this office askin whether the retroreflective tape required to outline school bus emergency exits can, in the case of the rear emergency door, be placed on the door itself. The short answer is no. You stated that the State of Connecticut requires that school bus bumpers be black. You further stated that one school bus manufacturer supplied buses with the bottom piece of the retroreflective tape installed on the rear bumper. You then noticed that a number of school buses from a different manufacturer had the bottom part of the tape installed on the door itself. You asked whether the language of S5.5.3 of Federal Motor Vehicle Safety Standard (FMVSS) No. 217, Bus emergency exits and window retention and release, permitted the installation of the retroreflective tape on the door itself. Paragraph S5.5.3 of FMVSS No. 217 (49 CFR 571.217) provides: Each opening for a required emergency exit shall be outlined around its outside perimeter with a minimum 3 centimeters wide retroreflective tape, either red, white, or yellow in color, . . . This requirement was imposed by amendment to FMVSS No. 217 promulgated by a final rule published in the Federal Register on November 2, 1992 (57 FR 49413). In discussing this requirement in the preamble portion of the final rule, we said at 57 FR 49421: Accordingly, the final rule requires a minimum 1 inch wide strip of retroreflective tape, either red, white, or yellow in color, to be placed around the outside perimeter of the emergency exit opening, not the emergency exit itself (emphasis added). As you may know, the buses with the tape on the emergency exit doors have been recalled by the manufacturer. For information about the recall, you can contact the bus manufacturer, Thomas Built Buses, P. O. Box 2450, High Point, NC 27261. Enclosed for your information are two interpretative letters issued by this office on related issues pertaining to the retroreflective tape requirement. See letter to Mr. Thomas D. Turner, Manager, Engineering Services, Blue Bird Body Company, dated July 7, 1993, and letter to Mr. Turner dated March 28, 1994. I hope the above information is helpful to you. Should you have any further questions or need additional information, please feel free to contact Walter Myers of my staff at this address or at (202) 366-2992. Sincerely, Philip R. Recht Chief Counsel Enclosures";

ID: aiam4975

"Dear Mr. Danis: This responds to your letter about testing related t Federal motor vehicle safety standard No. 121, Air Brake Systems, (49 CFR 571.121). You explained that your company has recently conducted a compliance test on an articulated bus manufactured by MCI Greyhound Canada. According to your letter, the buses were tested using 28 psi for the brake actuation test and 40 psi for the brake release test. While these air pressures differ from the pressures specified in S5.3.3 and S5.3.4 for brake actuation and release times, you stated that MCI was relying on a July 23, 1976 interpretation issued by the agency to Mr. J.W. Lawrence of the White Motor Corporation that permitted such brake actuation and release pressures. We note that to be consistent with that interpretation, the maximum brake chamber pressure must have been 40 psi when the service reservoir pressure was at 100 psi. Your letter was not clear on that point. You asked whether this interpretation is still valid. As explained below, the answer is yes. In its inquiry to NHTSA, White Motor Corporation asked whether S5.3.3 and S5.3.4 of Standard No. 121 require minimum brake chamber actuation and release time pressures of 60 psi and 95 psi, respectively, or whether these air pressures are included in the sections only as 'bench marks' on which to base specifications for minimum actuation and release timing. In response, the agency's July 23, 1976 interpretation letter stated in relevant part that: Your understanding that S5.3.3 and S5.3.4 only specify the air pressures of 60 psi and 95 psi as the basis for timing requirements is correct. Neither value is intended as a requirement that the vehicle be designed to provide a certain level of brake chamber air pressure. The values were based on an understanding of the typical configuration of existing air brake systems at the time the final rule was issued. In response to your specific question, NHTSA's July 23, 1976 interpretation letter continues to be valid. I hope this information is helpful. If you have any further questions about NHTSA's safety standards, please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel Enclosure";

ID: aiam3034

Dear Mr. Bogner: This is in reply to your letter of June 18, 1979, asking about 'th history of the implementation of FMVSS 108 and the dates as to these proceedings.'; I assume that you are interested in the initial standards and not th many amendments that have occurred at frequent intervals since the first effective dates. An advance notice of proposed rulemaking was published in the *Federal Register* on October 8, 1966, inviting suggestions for all the initial Federal motor vehicle safety standards. The initial motor vehicle lighting requirement were proposed on November 30, 1966 (31 FR 15212, corrected at 31 FR 15600). Standard No. 108 published on February 3, 1967, however, (32 FR 2408, establishing 23 CFR 255.21, effective January 1, 1968) applied only to vehicles whose overall width was 80 inches or more. On the same day the agency (then known as the National Traffic Safety Agency, Department of Commerce) proposed 'MVSS No. 112' to become effective January 1, 1968, to cover all vehicles whose width was less than 80 inches (32 FR 2418). The same notice also proposed amendments to the just-issued Standard No. 108 which were adopted on December 16, 1967 (32 FR 18032) with varying effective dates. Instead of adopting 'Standard No. 112', the agency also amended Standard No. 108 on December 16, 1967 (32 FR 18033) to incorporate the proposed '112' requirements, for vehicles under 80 inches in overall width, but with an effective date of January 1, 1969. At least one amendment occurred before January 1, 1969 (See 33 FR 2994, February 15, 1968), and one interpretation (See 32 FR 8808, June 21, 1967), defining 'overall width'. A petition for review of boat trailer lighting requirements was filed in 1968, and the requirements upheld (See *Boating Industry Association* v. *Boyd*, 409 F.2d 408 (7th Cir., 1969, rehearing denied).; This is the history of the early days of Standard No. 108. The onl 'documentation' that might still exist would be microfiche copies of docket comments (Docket No. 9) which are warehoused in Virginia. The head of our technical reference service, Ms. Winifred Desmond (426-2728) may be able to assist you with these.; If you have any further questions you may call me at 426-9511. Sincerely, Z. Taylor Vinson, Senior Staff Attorney

ID: aiam3866

Dear Mr. Gill: This is in response to your letter of May 25, 1984, asking for a interpretation of Motor Vehicle Safety Standard No. 108. Table IV specifies that the minimum horizontal separation distance '(centerline to centerline of lamp)' for rear turn signal lamps on motorcycles is 9 inches. You have asked whether the 'centerline' refers to the distance between the lens centers, between the centers of the effective projected luminous areas, or between the bulb centers.; You asked for confirmation of your belief that the prope interpretation is found in the referenced SAE Standard, J588e, which contains the language 'Optical axes (filament centers),' implying that the correct distance is that between the 'bulb centers' as you term it.; We find no direct correlation between the phrases 'centerline t centerline of lamps' and 'optical axis (filament center).' The lamp is a device emitting light whereas 'optical axis (filament center)' does not refer to the lamp but only to a portion of its light-producing component. As that phrase is used in SAE J588e, it defines the method of measuring distances between bulbs in multi-compartment lamps for the purpose of testing for photometric requirements (paragraph 3.1), or in measuring the separation of the turn signal from the headlamp (paragraph 4.2, where, incidentally, it is expressed as the distance between filament and a lamp component, the retaining ring).; Taken literally, 'centerline to centerline of lamps' in our view mean the distance between lens centers. In the response to petitions for reconsideration of the center high-mounted stoplamp amendment (May 17, 1984), the question was asked whether the 'center' of the lamp was its geometric center, its optical center, or the center of the bulb filament. The agency replied that the center of the lamp is the geometric center. Since the purpose of the minimum separation requirement is to insure that the turn signal is perceived as such, we believe that the correct interpretation of 'centerline to centerline' is a measurement from the geometric center of one lamp to the geometric center of the other lamp. The geometric center would be synonymous with the term 'geometric centroid of lens' as used in SAE J1221 *Headlamp-Turn Signal Spacing*.; Sincerely, Frank Berndt, Chief Counsel

ID: medcoaches3277.cmc

Mr. Dick Mattice
Vice President Engineering
Medical Coaches
399 Co Hwy 58
PO Box 129
Oneonta, NY 13820-0129

Dear Mr. Mattice:

This responds to your letter in which you asked about the requirements of Federal Motor Vehicle Safety Standard (FMVSS) Nos. 403, Platform lift systems for motor vehicles, and 404, Platform lift installations in motor vehicles, as they apply to platform lifts and mobile medical units manufactured by your company. I have addressed your questions below.

By way of background, the National Highway Traffic Safety Administration (NHTSA) has authority to prescribe safety standards applicable to new motor vehicles and new items of motor vehicle equipment (49 U.S.C. Chapter 301). Under this authority, NHTSA adopted FMVSS Nos. 403 and 404, which establish minimum performance standards for platform lifts designed for installation on motor vehicles and motor vehicles installed with platform lifts, respectively. The purpose of the standards is to protect individuals that are aided by canes, walkers, wheelchairs, scooters, and other mobility devices and rely on platform lifts to enter/exit a motor vehicle. The standards are effective December 27, 2004.

In your letter, you stated that your company manufactures trailers equipped with mobile medical units (e.g., MRI, PET, PET/CT units). You explained that all of these units have patient lifts that "fold and store in an under-floor skirt compartment during transit." You further explained that although the lift design "is primarily used for non-ambulatory patients on gurneys, it could just as easily be used for wheelchair-bound patients."You stated that the lifts are designed so that a gurney would be parallel to the trailer when on the platform, and therefore a wheelchair would also be oriented parallel to the trailer when on the platform. You then asked several questions regarding the application of FMVSS Nos. 403 and 404 to the lifts and vehicles manufactured by your company.

1) Platform Dimensions

Your letter explained that:

[The] lifts are designed so that a gurney will be parallel to the trailer when entering or leaving the trailer. The platform itself is 84" wide x 38" deep (inner roll stop to ramp). As a result, a wheelchair would also be parallel to the trailer and not perpendicular.

You then asked if the lift orientation and dimensions would be permitted under the new standards.

Before discussing lift dimension requirements, it is important to note that FMVSS Nos. 403 and 404 differentiate between public use lifts and private use lifts, and that different requirements apply based on a lifts designation. Under FMVSS No. 404, lift-equipped buses, school buses and multipurpose passenger vehicles other than motor homes with a GVWR greater than 4,536 kg (10,000 pounds) must be equipped with a lift certified to all requirements applicable to a public use lift (see S4.1.1). All other lift-equipped motor vehicles must be equipped with a platform lift certified as complying with either the public use or private use lift requirements (see S4.1.2). FMVSS No. 404 does not include trailers as a vehicle type that must be equipped with a public use lift. Therefore, the trailers manufactured by your company may be equipped with lifts certified to the public or private lift requirements.

FMVSS No. 403 does not establish requirements specifying the orientation of a wheelchair during lift operation. For public use lifts, S6.4.2.1 of FMVSS No. 403 does establish a minimum operating platform volume, which is based on the sum of an upper and lower part (see Figure 3; copy enclosed). The lower part must accommodate a rectangular solid that has a minimum width of 725 mm (28.5 in) along the platform surface and a minimum height of 50 mm (2 in). The upper part must accommodate a rectangular solid that has a base with a minimum dimension of 760 mm (30 in) wide by 1,220 mm (48 in) long and a minimum height of 711 mm (28 in). While the standard specifies that the base of the upper part must be tangent to the top surface of the lower rectangular volume and the centroids of both parts must coincide with the vertical centroidal axis of the platform, the standard does not specify the orientation of the upper part to the lower part. There is nothing preventing the upper part from being rotated in relation to the lower part.

Based on the information provided in your letter, your platform would conform to the minimum operating platform volume requirement for public use lifts. Your platform is 84 inches by 38 inches and would be able to accommodate an upper and a lower rectangular solid of the minimum size required. Further, if you were to certify the lift to the private use lift requirements, you would be required to specify the unobstructed platform operating volume and include it in the lift insert to the vehicle owners manual.

2) Wheelchair retention device impact test

Again, you stated that upon loading, a wheelchair is intended to be oriented parallel to the trailer. You ask if S7.7, Wheelchair retention device impact test, must be performed in this orientation, with the wheelchair accelerated in a direction parallel to the trailer.

The wheelchair retention device impact test verifies the integrity of the inner roll stop and the wheelchair retention device or outer barrier. The test simulates uncontrolled acceleration of a wheelchair or mobility aid when loading a platform. When loading the platform at the vehicle floor level, a mobility aid may accelerate forward and strike the wheelchair retention device. When loading the platform at ground level, a mobility aid may accelerate forward and strike the inner roll stop. In both instances, the mobility aid has the opportunity to achieve a measure of speed and momentum in a direction perpendicular to the trailer before striking a barrier.

In FMVSS No. 403, S7.7.2.3 requires a test device to be positioned with its plane of symmetry coincident with the lift reference plane. This results in the test device oriented perpendicular to the vehicle. The reference to the orientation of the test device in S7.7 refers to whether a wheelchair is loaded onto the platform in the forward or reverse direction.

On your vehicles, a mobility aid is loaded in a perpendicular direction to the trailer, even though once loaded it is positioned parallel to the trailer. Once the mobility aid is positioned on the platform parallel to the vehicle body, it is stationary. Even if it were to move forward or rearward, because of limited space on the platform, it could not achieve the level of momentum that is possible when rolling onto a platform from the vehicle or ground. However, during loading, an unimpeded mobility aid could heavily impact either a wheelchair retention device or outer barrier. Accordingly, the wheelchair retention device impact test would be performed on the wheelchair retention device/outer barrier and the inner roll stop.

3) Public use verses private use lift

Your letter asked if the lifts installed on the mobile medical units manufactured by your company would be required to be certified as public use lifts. As explained in response #1, because the vehicles manufactured by your company are trailers, the lifts could be certified as complying with either the public use or private use lift requirements.

4) Platform freefall limits

Under S6.6 of FMVSS No. 403, no portion of a platform may fall vertically faster than 305 mm (12 in) per second in the event of any single-point failure of systems for raising, lowering, or supporting the platform. Your letter asked if a failure of a hydraulic line by rupture constitutes a single-point failure.

If a system for raising, lowering, or supporting a platform were to include a hydraulic line, then the rupture of that line would constitute a single-point failure under S6.6. Therefore, if the hydraulic line were to rupture, the platform must not fall vertically faster than permitted by the standard. Additionally, you may need to evaluate other failures, as S6.6 applies to any single-point failure.

I hope that you find our responses helpful. If you have any additional questions, please contact Mr. Chris Calamita of my staff at (202) 366-2992.

Sincerely,

Jacqueline Glassman
Chief Counsel

Enclosure
ref:403#404
d.6/25/04

ID: nht91-1.4

DATE: 01/01/91

FROM: UNDER SECRETARY -- MINISTRY OF COMMERCE & INDUSTRY, KUWAIT

COPYEE: THE MINISTER'S OFFICE; THE UNDER SECRETARY; INDUSTRIAL AFFAIRS; STANDARDS & METROLOGY DEPT.

ATTACHMT: ATTACHED TO LETTER DATED 11-13-92 FROM PAUL J. RICE TO UNDER SECRETARY, KUWAIT MINISTRY OF COMMERCE AND INDUSTRY (PART 574; STD. 109; STD. 119; A40; PART 571)

TEXT: We have studied your above mentioned standards with interst and we would appreciate if you please reply to following questions:

1) Do all tyres manufactured and sold in the US must bear the (DOT) mark?

2) What are the basises for granting the right to use the (DOT) mark by the manufacturer on their tyres?

3) Is the (DOT) mark required for local consumed and exported tyres also?

4) Is there a validity time for the use of the (DOT) mark?

5) What is the relation ship between your administnation and the Department Of Transportation concerning the implementation of the use of the (DOT) mark?

6) What are the legal responsibility of the manufacturer by using the mark.

7) What are the responsibility of the manufacturer in case of violation of mark's roles.

We would appreciate if you please kindly furnish us with all information and document concerning the above mentioned subject.

Thank you in advance for your cooperation.

ID: nht89-3.48

TYPE: INTERPRETATION-NHTSA

DATE: 11/29/89 EST

FROM: JEFFREY R. MILLER -- NHTSA ACTING ADMINISTRATOR

TO: JOHN D. DINGELL -- CHAIRMAN, COMMITTEE ON ENERGY AND COMMERCE UNITED STATES HOUSE OF REPRESENTATIVES

TITLE: NONE

ATTACHMT: LETTER DATED 09/22/89 FROM JOHN D. DINGELL -- HOUSE TO JEFFREY R. MILLER; LETTER DATED 08/25/89 FROM CONSTANCE A. MORELLA -- HOUSE TO NORMAN Y. MINETA -- HOUSE; LETTER DATED 07/31/89 FROM W. MARSHALL RICKERT -- MVA TO CONSTANCE A. MORELLA; LETT ER DATED 07/08/88 FROM ERIKA Z. JONES -- NHTSA TO NORMAN D. SHUNWAY -- CONGRESS; STANDARD 205; LETTER DATED 11/01/88 FROM ERIKA Z. JONES -- NHTSA TO BEVERLY B. BYRON -- HOUSE; STANDARD 205

TEXT: Dear Mr. Chairman:

Thank you for your letter of September 22, 1989, forwarding Representative Morella's letter inquiring about the requirements of Federal law and regulations as they apply to the tinting of motor vehicle windows for medical reasons. We recently began a ru lemaking proceeding on the issue of tinting, and I welcome this opportunity to discuss the matter.

The enclosures to Ms. Morella's letter described a case in which a person suffers from a skin disease called vitiligo and was advised to avoid exposure to the sun's rays. The presumption is that this person needs more protection from the sun than that a fforded by vehicle windows that conform to the Federal standard.

Federal Motor Vehicle Safety Standard No. 205, Glazing Materials, establishes a minimum 70 percent light transmissibility for glazing at levels "requisite for driving visibility," which includes all windows in passenger cars. When a requirement is estab lished in a Federal safety standard, the National Traffic and Motor Vehicle Safety Act prohibits any person from manufacturing, selling, or importing a new vehicle that does not comply with that requirement. The Safety Act does not provide for individua l medical exemptions.

Similarly, the Safety Act prohibits any manufacturer, distributor, dealer, or repair business from "rendering inoperative" an element of design required by a safety standard, such as minimum light transmissibility. This "render inoperative" prohibition applies to vehicles after sale to purchasers. Neither this "render inoperative" provision nor any other Federal requirement would prohibit an individual vehicle owner from modifying their own vehicles, even if the modifications cause the vehicle to no l onger comply with the Federal safety standards. Thus, an individual vehicle owner can make whatever modifications he or she likes, for medical or any other reasons, without violating Federal law. However, the individual States have the authority to regu late modifications that owners may make to their vehicles, and

2 many States have chosen to regulate window tinting. For your reference, I have enclosed copies of our July 8, 1988 letter to Representative Shumway and our November 1, 1988 letter to Representative Byron on this subject.

The minimum light transmissibility requirement in Standard No. 205 represents a balancing of legitimate competing interests. On the one hand, safety considerations dictate that drivers must be able to see and analyze the traffic situation in which the v ehicle is being operated and react to that situation properly and promptly. To the extent that some of the available light is not transmitted through the vehicle glazing, the driver's ability to react to the traffic situation is potentially delayed. Th is is especially true under low light conditions, such as occur at night and on very overcast days.

On the other hand, there are legitimate reasons for allowing some tinting of vehicle windows. These include avoiding excessive heat for all vehicle occupants, reducing glare for the driver, preserving the vehicle interior, and helping persons with medic al conditions that are sensitive to the sun's rays.

NHTSA balanced these competing interests by establishing the current 70 percent minimum light transmissibility requirement in Standard No. 205. However, the agency was asked in a petition for rulemaking to reexamine this balance and to permit darker tin ting of windows, by lowering the minimum light transmissibility requirement. We decided to reexamine whether the current minimum light transmibility requirement continues to represent the most appropriate and reasonable balance of the competing interest s.

Accordingly, on July 20, 1989, this agency published a request for comments on a comprehensive review of the 70 percent light transmissibility requirement for side and rear window glazing in passenger automobiles. One of the issues raised was the light transmissibility standard's effect on those who need more protection from the sun's ultraviolet rays. The comment period for this notice closed on September 18, 1989. The agency received nearly one hundred comments on this issue and is currently review ing those comments. We will notify you and Ms. Morella when we announce our decision.

I have placed a copy of your letter and this response in the public docket for this rulemaking action. I hope this information is helpful.

Sincerely,

ENCLOSURES

ID: 1985-01.30

TYPE: INTERPRETATION-NHTSA

DATE: 02/12/85

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: Addressee not given

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of August 30, 1984, (not received until October 17, 1984) with respect to questions of compliance of lighting and bumper requirements on a vehicle equipped with a variable height control system.

Standard No. 108 requires that the center of a headlamp lens be not less than 22 inches from the road surface. You stated that this minimum might not be met with respect to certain headlamp configurations when the ignition is off, and the hydraulic pressure in the height control system relaxes, a period of approximately three hours. You believe that compliance with the mounting height requirement should be judged "with the ignition switch in only the 'on' position," the apparent point at which the height control system begins to operate.

We believe that the minimum height requirement should be met for any lamp at any time in which it is operated for its intended purpose. Since vehicles at rest do not require use of headlamps, the minimum height would be measured at the point after the ignition is on and when the car begins to travel (your letter implies that the time lag between turning on the ignition and restoration of a complying mounting height is a matter of seconds). On the other hand, the hazard warning signal lamps are frequently operated when the vehicle is stopped, and therefore the minimum mounting height of turn signal lamps, through which they operate, must be met with the ignition off, even if the system requires three hours to deplete itself and lower the vehicle to its minimum height.

We also call to your attention paragraph S4.1.3 which forbids the installation of motor vehicle equipment which impairs the effectiveness of lighting equipment required by the standard, and ask that you consider whether a height control system would change vehicle height, pitch, roll, etc., in response to some external or internal condition, in a manner which would affect the performance of headlamps and other lighting equipment.

You have also asked, in essence, which conditions of operation of the system are appropriate for the pendulum and barrier impact tests of the bumper standard, 49 CFR Part 581. Under Sec. 581.5(c), the suspension system is to remain in adjustment and operate in the normal manner; under Sec. 581.6(c) the engine is operating at idling speed. In our opinion, the vehicle is required to meet the pendulum test of Part 581 in any vehicle use scenario in which the system operates, and the barrier test of Part 581 when the engine is idling.

Finally, you requested confidentiality for all information submitted which pertains to the variable height control system. After carefully reviewing the documents, I have determined that your request should be granted. The release of these documents could cause substantial injury to the competitive position of your company. Therefore, I am withholding from the public your letter which contains a detailed description of the variable height control system currently under consideration. I am also deleting all references to the company name. I will instruct all agency personnel having access to this information to accord it confidential treatment.

I hope that this answers your questions.

ID: nht81-2.20

DATE: 05/06/81

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: J. G. Frail

TITLE: FMVSS INTERPRETATION

TEXT:

U.S. Department of Transportation National Highway Traffic Safety Administration

May 6, 1981 NOA-30

Mr. John G. Frail P.O. Box 581 Bronxville, New York 10708

Dear Mr. Frail:

This is in reply to your letter of April 9, 1981, to this agency asking, with respect to Motor Vehicle Safety Standard No. 108, "whether the minimum edge to edge separation distance between lamp and tail or stop lamp of 4 inches is measured outside of the lamp or inside of the lamp." You have asked this question in behalf of an "OEM supplier" in Germany.

The requirement in Table IV of Standard No. 108 is that the minimum edge to edge separation distance between a turn signal lamp and a tail or stop lamp be 4 inches while the turn signal lamps themselves must have a minimum separation distance of 9 inches between their centerlines. (Your design is somewhat confusing as it depicts centerlines of stop lamps and turn signal lamps at 9 inches.) We interpret this as meaning the minimum separation distance between the edge of lighted area to be 4 inches, as depicted in "B" in your design. Of course, final responsibility for compliance with this requirement rests on the vehicle manufacturer rather than the equipment manufacturer.

Sincerely,

Original Signed By

Frank Berndt Chief Counsel

John G. Frail Post Office Box 581 Bronxville, New York 10708

April 9, 1981

U.S. Department of Transportation National Highway Traffic Safety Administration Washington, D.C. 20590

Re: FMVSS 108 interpertation.

Gentlemen:

The attachment from the Federal Motor Vehicle Safety Standards and Regulations from ULO-WERK of West Germany questions the following:

The contents of the attachment are that of Table III & Table IV (Part 571; S 108 11/12). They are interested, as illustrated by the client, the interpertation as to whether the minimum edge to edge separation distance between lamp and tail or stop lamp of 4 inches is measured outside of the lamp or inside of the lamp.

They have not specified their concern other than being OEM suppliers. This question may have risen as a result of two manufacturers supplying the lamp for one vehicle. The outside ornamentation of the lamp may be the question resulting in how one should measure the distance. Also, if we assume the distance is basically for light output of the lamp (night time driving) they may have a reasonable question.

So that I may inform our client, please advise in writing the proper interpertation of the subject specification as to wether the measurement of 4 inches regarding the distance between tail-stop-lamp and indicator lamp will be measured at the inside or outside of the spare lens.

Please forward your answer to my above post office box address at your earliest convenience.

Very truly yours,

John G. Frail

Attachment Omitted

ID: 8701

Mr. Richard A. Zander
AlliedSignal Automotive Proving Grounds
32104 State Road 2
New Carlisle, IN 46552

Dear Mr. Zander:

This responds to your letter asking about the fade and recovery requirements of Federal Motor Vehicle Safety Standard No. 105, Hydraulic Brake Systems. I apologize for the delay in our response. You noted that the standard requires vehicles with a GVWR of 10,000 pounds or less to be capable of making a specified number of fade stops "at a deceleration not lower than 15 fpsps for each stop." You stated that you are aware of a number of different understandings within the industry of the quoted phrase, and requested an interpretation as to whether vehicles must be capable of maintaining an average deceleration of at least 15 fpsps or a minimum deceleration of at least 15 fpsps. As discussed below, vehicles must be capable of maintaining a minimum deceleration of at least 15 fpsps.

By way of background information, the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381, et seq.) authorizes the National Highway Safety Administration (NHTSA) to issue safety standards applicable to new motor vehicles and items of motor vehicle equipment. NHTSA does not, however, approve motor vehicles or motor vehicle equipment. Instead, the Safety Act establishes a "self-certification" process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards.

Manufacturers must have some independent basis for their certification that a product complies with all applicable safety standards. This does not necessarily mean that a manufacturer must conduct the specific tests set forth in an applicable standard. Certifications may be based on, among other things, engineering analyses, actual testing, and computer simulations. Whatever the basis for certification, however, the manufacturer must certify that the product complies with a standard as it is written, i.e., that the vehicle will pass all applicable requirements if it is tested exactly according to the standard's test conditions and other specifications.

Standard No. 105's fade and recovery test requirements are set forth in S5.1.4. These requirements must be met under the conditions prescribed in S6, when tested according to the procedures set forth in S7. See S5.1. The purpose of the fade and recovery test requirements is to help ensure that brakes retain adequate stopping capacity during and after exposure to conditions cause by prolonged or severe use, such as long, downhill driving.

The standard specifies two fade and recovery tests for vehicles with a GVWR of 10,000 pounds or less. Each of the fade and recovery tests consists of three parts: (1) baseline check stops, (2) fade stops, and (3) recovery stops. The requirements for the fade stops are set forth in S5.1.4.2(a), which states that:

Each vehicle with a GVWR of 10,000 lbs or less shall be capable of making 5 fade stops (10 fade stops on the second test) from 60 mph at a deceleration not lower than 15 fpsps for each stop, followed by 5 fade stops at the maximum deceleration attainable from 5 to 15 fpsps."

As you noted, S5.1.4.2(a) must be read in conjunction with S7.11.2.1, which sets forth the procedure for conducting the fade stops. It reads, in relevant part, as follows:

Make 5 stops from 60 mph at 15 fpsps followed by 5 stops at the maximum attainable deceleration between 5 and 15 fpsps for each stop. ... Attain the required deceleration within 1 second and, as a minimum, maintain it for the remainder of the stopping time. Control force readings may be terminated when the vehicle speed falls to 5 mph. (Emphasis added.)

The words "required deceleration" in S7.11.2.1 refer to 15 fpsps. (That value is set forth both in S5.1.4.2(a) and the first sentence of S7.11.2.1.) Thus, in conducting fade stops, within one second of beginning a stop, a deceleration of 15 fpsps must be attained. S7.11.2.1 then specifies that, "as a minimum," the required deceleration (15 fpsps) must be maintained for the remainder of the stopping time. (The word "it" in the highlighted sentence refers back to the phrase "required deceleration.") Thus, after a deceleration of 15 fpsps is attained (within one second of beginning the stop), the deceleration cannot drop below 15 fpsps even momentarily.

You stated that you are aware of the following three understandings within the industry concerning the meaning of this requirement:

1.The average deceleration for the stop must be greater than 15 fpsps. The average deceleration is calculated from one second after the stop begins to a vehicle speed of 5 mph.

2.After 1 second the deceleration can not drop below 15 fpsps even for an instant. If the deceleration drops below 15 fpsps at any time it is considered a failure even if the average deceleration is greater than 15 fpsps.

3.The average deceleration for the stop must be greater than 15 fpsps and the deceleration must be greater than 15 fpsps for at least 75% of the stop excluding the first second of the stop.

Of the three understandings, the first and third are inconsistent with the plain wording of S7.11.2.1 which specifies that, after the required 15 fpsps deceleration is attained (within one second of beginning the stop), it must, as a minimum, be maintained for the remainder of the stopping time. The first and third understandings would, among other things, replace S7.11.2.1's specification that the 15 fpsps deceleration be maintained as a "minimum" with one that it be maintained as an "average."

The second understanding is largely correct. It is correct to state that, in conducting a fade stop, after a 15 fpsps deceleration is attained (within one second of beginning the stop), the deceleration cannot drop below 15 fpsps even for an instant. However, if the deceleration did drop below 15 fpsps, that would not necessarily indicate a "failure" but might simply be an invalid test. As you note in your letter, a deceleration might fall below 15 fpsps because the driver did not compensate for in-stop fade. However, if a vehicle was unable to pass Standard No. 105's fade stop test requirements at the specified deceleration rates, it would not comply with the standard, notwithstanding the fact that it might be able to pass the requirements at slightly lower deceleration rates.

You stated in your letter that the second understanding appears to not consider the intent of the fade procedure, the intent being that a vehicle must be capable of making multiple high deceleration stops in a short period of time without drastic changes in effectiveness. As discussed above, the purpose of the fade and recovery test requirements is to help ensure that brakes retain adequate stopping capacity during and after exposure to conditions cause by prolonged or severe use, such as long, downhill driving. If a vehicle was unable to pass Standard No. 105's fade stop test requirements at the specified deceleration rates, it would indicate inadequate stopping capability during conditions caused by prolonged or severe use, such as long, downhill driving.

You also stated that in the Laboratory Test Procedure for Standard No. 105, published by NHTSA's Office of Vehicle Safety Compliance (OVSC), the data sheet for the fade stops requests the following information for the deceleration: "Average Sust Decel." You stated that it therefore appears that NHTSA's interpretation of the phrase "at a deceleration not lower than 15 fpsps for each stop" is "the average sustained deceleration."

It is incorrect to interpret the OVSC Laboratory Test Procedures as limiting the requirements of the Federal motor vehicle safety standards. I call your attention to the following note which is set forth at the beginning of the Laboratory Test Procedure:

The OVSC Laboratory Test Procedures, prepared for use by independent laboratories under contract to conduct compliance tests for the OVSC, are not intended to limit the requirements of the applicable FMVSS(s). In some cases, the OVSC Laboratory Test Procedures do not include all of the various FMVSS minimum performance requirements. Sometimes, recognizing applicable test tolerances, the Test Procedures specify test conditions which are less severe than the minimum requirements of the standards themselves. Therefore, compliance of a vehicle or item of motor vehicle equipment is not necessarily guaranteed if the manufacturer limits certification tests to those described in the OVSC Laboratory Test Procedures.

I am enclosing a copy of the most recent version of the Laboratory Test Procedure for Standard No. 105, in response to your request. I hope this information is helpful. If you have any further questions, please feel free to contact David Elias of my staff at this address or by telephone at (202) 366-2992.

Sincerely,

John Womack Acting Chief Counsel

Enclosure

ref:105 d:3/23/94