ID: nht73-4.50

DATE: 08/28/73

FROM: AUTHOR UNAVAILABLE; James B. Gregory; NHTSA

TO: Meteor Works

TITLE: FMVSR INTERPRETATION

TEXT: In your letter of July 5, 1973, you express two concerns about the treatment of multipurpose passenger vehicles under the Motor Vehicle Information and Cost Savings Act.

Your first concern is that the standards to be issued under the act will apply to all passenger motor vehicles, and will include multipurpose passenger vehicles unless the agency expressly exempts them. As we stated in the notice of proposed rulemaking on the new bumper standard, we are proposing to exempt multipurpose passenger vehicles from the initial standard. The continuance of this exemption depends on a variety of considerations, and we would appreciate the benefit of your views on the subject.

Your second concern is that the definition of "multipurpose passenger vehicle" in the safety standards (49 CFR 571.3(b)) differs from the definition of the same term in the Cost Savings Act. Although the definitions are fundamentally similar, the safety standards definition limits the MPV category to vehicles designed to carry 10 persons or less, while the Cost Savings Act definition includes somewhat larger vehicles, up to a capacity of 12 persons. We do not foresee any problems as a result of this difference, but if problems arise, it would be possible through rulemaking to restrict the applicability of a cost savings standard to MPV's having a capacity of 10 persons.

ENC.

The Administrator National Highway Traffic Safety Administration

5 Jul 1973

Rover British Leyland UK Ltd manufacturers the Land Rover multi-purpose passenger vehicle which is sold in the United States by British Leyland Motors Inc., 600 Willow Tree Road, Leonia, New Jersey.

The Land Rover is designed to operate on and off road and to carry special equipment and is therefore incapable of meeting some of the requirements of passenger cars, for example bumper heights, without impairment of its special performance capabilities. This fact is recognised in the differential application of the Federal Motor Vehicle Safety Standards to passenger cars and multi-purpose passenger vehicles. We wish to ensure that a clear distinction between these two classes of vehicle is made and continue to be made and for this reason we are concerned that the Motor Vehicle Information and Cost Savings Act adopts a different definition for multi-purpose passenger vehicle from that adopted in Part 371 of the Federal Motor Vehicle Safety Standards.

We quote from the Motor Vehicle Information and Cost Savings Act "(1) The term "passenger motor vehicle" means a motor vehicle with motive power, designed for carrying twelve persons or less, except (A) a motorcycle or (B) a truck not designed primarily to carry its operator or passengers.

(2) The term "multipurpose passenger vehicle" means a passenger motor vehicle which is constructed either on a truck chassis or with special features for occasional off-road operation."

and from the Federal Motor Vehicle Safety Standards "Passenger car" means a motor vehicle with motive power, except a multipurpose passenger vehicle, motorcycle, or trailer designed for carrying 10 persons or less."

"Multipurpose passenger vehicle" means a motor vehicle with power, except a trailer, designed to carry 10 persons or less which is constructed either on a truck chassis or with special features for occasional off-road operation."

It is obvious that the two definitions are different although the vehicles to be defined are the same.

Our concern is that the term "multi-purpose passenger vehicle" in the Motor Vehicle Information and Cost Savings Act is embraced by the term "passenger motor vehicle". Thus any requirements written under this Act for a "passenger motor vehicle" apply automatically to a "multi-purpose passenger vehicle" unless the latter is specifically exempted. Such exemption is expected to be necessary in consequence of the different purpose for which the vehicles are designed.

Secondly the Seating capacity used in the definitions is 12 persons or less in the case of the Motor Vehicle Information and Cost Savings Act and 10 persons or less in the case of the Federal Motor Vehicle Safety Standards.

The most satisfactory solution would be for the Motor Vehicle Information and Cost Savings Act to adopt the definitions of "Multi-purpose Passenger Vehicle" and "Passenger Car" of Part 371 of the Federal Motor Vehicle Safety Standards, if however such an administrative solution is not possible perhaps NHTSA would consider seeking a technical amendment to work this out.

We would be pleased to receive your comments on this proposal and particularly if we have to take any further action to request such an amendment or how the different definitions will be interpreted.

C J GOODE SAFETY CO-ORDINATOR (PASSENGER CARS)

ID: nht94-7.21

DATE: March 25, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Thomas D. Turner -- Manager, Engineering Services, Blue Bird Body Company

TITLE: None

ATTACHMT: Attached to letter dated 11/15/93 from Thomas D. Turner to John Womack

TEXT:

This responds to your letter of November 15, 1993, in which you requested an interpretation of the final rule issued by this agency on January 15, 1993, 58 FR 4586, which amended Federal Motor Vehicle Safety Standard (FMVSS) No. 222, School Bus Passenger Seating and Crash Protection to include requirements for wheelchair securement devices and occupant restraint systems.

You referred to the second sentence in S5.4.3.2 of the standard which provides in pertinent part: "When more than one wheelchair occupant restraint shares a common anchorage, the anchorage shall be capable of withstanding a force of 13,344 Newtons multiplied by the number of occupant restraints sharing that anchorage." You stated that you believe that this language is intended to address the situation where restraints from two different wheelchair occupant restraint systems share a common anchorage, and is not intended to address the situation "where the lower end of an upper torso restraint joins the pelvic restraint and goes to one of the rear floor anchorages of a single occupant's restraint system." You stated that if the latter, the floor anchorage would be required to withstand a force of 13,344 Newtons each for the upper torso restraint and the pelvic restraint; and if the wheelchair was also secured to that floor anchorage, the anchorage would be required to withstand 3 x 13,344 Newtons.

Your letter included two figures illustrating typical wheelchair securement and occupant restraint system designs. In Figure 1, the upper torso restraint is attached to the lap belt at the buckle, and the lap belt is attached to the vehicle at the same anchorage as the rear anchorage for the wheelchair securement device. In Figure 2, the upper torso restraint is also attached to the lap belt; however, the lap belt is attached to the rear wheelchair securement device instead of the wheelchair securement anchorage. You asked for verification that the required load for the rear anchorages for both designs is 2 x 13,344 Newtons rather than 3 x 13,344 Newtons.

You are correct that the load for the rear anchorages for both these designs would be 26,688 Newtons (2 x 13,344 Newtons). The relevant section to determine this load is S5.4.3.2(e) which states:

When a wheelchair securement device and an occupant restraint share a common anchorage, including occupant restraint designs that attach the occupant restraint to the securement device or the wheelchair, the loads specified by S5.4.1.3 (13,344 Newtons) and S5.4.3.2 (13,344 Newtons) shall be applied simultaneously...

The term "wheelchair occupant restraint" includes both the pelvic and upper torso restraints (see S5.4.4). In your designs, each rear floor anchorage would be required by S5.4.3.2(e) to withstand a combined force of 26,688 Newtons, which includes the load specified for the wheelchair occupant restraint and the load specified for the wheelchair securement device.

The second sentence of S5.4.3.2, which you quoted in your letter, addresses the situation where the wheelchair occupant restraints for more than one wheelchair, e.g. two wheelchairs, are secured to the same floor anchorage. This requirement parallels a requirement in S5.4.1.3 which addresses the situation where the wheelchair securement devices for more than one wheelchair are secured to the same floor anchorage. Thus, for example, if either of your designs were installed in a bus such that the right rear anchorage was shared with another identical wheelchair securement and occupant restraint system (functioning as the left rear anchorage for the second system), that floor anchorage must be capable of withstanding a force of 13,344 Newtons for each occupant restraint system and 13,344 Newtons for each wheelchair securement system, for a total force of 4 x 13,344 Newtons, such force to be applied simultaneously as required by S5.4.3.2(e).

I hope you find this information helpful. If you have any other questions, please contact Walter Myers of my staff at this address or by phone at (202) 366-2992.

ID: 19011.drn

The Honorable Dave Weldon
U. S. House of Representatives
2725 Judge Fran Jamieson Way, Building C
Melbourne, FL 32940

ATTN: Mr. Terry Mulford, Senior Caseworker

Dear Congressman Weldon:

Thank you for your letter on behalf of your constituents, Mr. David Thatcher and Ms. Janice Pound, of the Indian River City United Methodist Church, concerning Federal regulations for school buses. Your letter was referred to my office for reply, because the National Highway Traffic Safety Administration (NHTSA) is the agency responsible for administering Federal school bus requirements.

Your letter explains that the Indian River City United Methodist Church plans to start an after school child care program, and plans to purchase vans for use in transporting the children in the program. Your constituents have heard that "the state will be attempting to outlaw passenger vans for transporting children to/from school." They ask whether the church may use a passenger van and have other questions about school bus requirements.

I appreciate this opportunity to explain our school bus requirements. As explained below, our statutory authority applies to dealers that sell new vehicles. We do not regulate the use of vans, but we do require persons to sell school buses if the seller is selling a new "bus" (which includes a 10+ passenger van) and knows that the new bus (van) will be used to transport children to or from school or related events.

NHTSA's statute at 49 U.S.C. 30112 requires any person selling or leasing a new vehicle to sell or lease a vehicle that meets all applicable Federal safety standards. Under our regulations, a "bus" is any vehicle, including a van, that has a seating capacity of 11 persons or more. A "school bus" is any bus which is likely to be "used significantly" to transport preprimary, primary, and secondary students "to or from school or an event related to school" (emphasis added). Thus, a large van (such as one designed for 15 passengers) that is likely to be used significantly to transport students to or from school or school-related events is a "school bus." If a dealer sells a new bus (van) knowing that the bus is likely to be used significantly for such transportation, the seller must sell a bus that has been certified as meeting comprehensive Federal school bus safety standards.

This means that, with regard to your constituents' planned purchase of a bus (van), if a dealer knows that a new bus it is about to sell is likely to be used significantly (e.g., on a regular basis) to carry children to or from school or school-related events, the dealer must sell a bus that has been certified as meeting Federal school bus standards. A failure to sell a school bus in this situation can subject the dealer to substantial civil penalties from NHTSA.

Because use of a vehicle is regulated by the individual states, Florida may have requirements that could affect your constituents' use of the van. For information on Florida's requirements for transporting children to or from school, Mr. Thatcher and Ms. Pound can contact Florida's State Director of Pupil Transportation:

Charles F. Hood, Director
School Transportation
Florida Department of Education
Suite 824, Fla. Educ. Ctr.
Tallahassee, FL 32399-0400
Telephone number: (904) 488-4405

Florida may have a school bus definition that is used to determine which vehicles are subject to the state's school bus use requirements. Florida state administrators can answer Ms. Pound's question about the definition of a school bus, and the date by which school bus operators must comply with any prohibitions against using passenger vans for transporting children to or from school.

In closing, we wish to emphasize that school buses are one of the safest forms of transportation in this country, and that we therefore strongly recommend that all buses that are used significantly to transport school children be certified as meeting NHTSA's school bus safety standards. Further, using 10+ passenger vans that do not meet the school bus standards to transport students could result in increased liability in the event of a crash. Since such liability would be determined by State law, your constituents may wish to consult with an attorney and insurance carrier for advice on this issue.

I hope this information is helpful. I am also enclosing our publication, "Frequently Asked Questions About School Bus Safety Requirements." If you have any further questions, please feel free to contact me at this address or by telephone at (202) 366-2992.

Sincerely,
Frank Seales, Jr.
Chief Counsel
Enclosure
ref:VSA#571.3
d.11/20/98

ID: nht87-1.10

TYPE: INTERPRETATION-NHTSA

DATE: 01/12/87

FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA

TO: Fred E. Maynard

TITLE: FMVSS INTERPRETATION

TEXT:

Mr. Fred E. Maynard 13208 Creek Park Lane Poway, CA 92064

Dear Mr. Maynard:

This is in reply to your letter of November 14, 1986, to Taylor Vinson of this Office with respect to an automotive lighting product that you have developed.

According to your letter the VISICOM is an electronic message sending unit which incorporates a center high-mounted stoplamp "which will meet all of the standards required by Regulation 108 as to size, light intensity, angle of visibility, etc.." You hav e asked for an opinion "on any potential current or future legal problems that might arise when this product is marketed."

I will be pleased to discuss the relationship of your device to Federal Motor Vehicle Safety Standard No. 108 and the National Traffic and Motor Vehicle Safety Act, but we cannot advise you of problems you might encounter under State or common law. Stand ard No. 108 covers original vehicle equipment and items manufactured to replace original equipment. Paragraph 54.4 of Standard No. 108 states, in pertinent part, that "...no high-mounted stoplamp shall be combined with any other lamp or reflective device ." In our view, this precludes you from offering the VISICOM as either an original center high-mounted stoplamp, or as one intended to replace such a stoplamp on any passenger car manufactured on or after September 1, 1985.

However, you are not precluded by Standard No. 108 or the Act from offering this device as aftermarket equipment on passenger cars manufactured before September 1, 1985. Whether VISICOM is acceptable on these vehicles must be determined by the laws of ea ch State in which the device will be sold or used.

Thank you for your interest in safety. If you have further questions we would be pleased to answer them.

Sincerely, Erika Z. Jones Chief Counsel

November 14, 1986

Mr. Taylor Vinson, Legal Council NHTSA, Dept. of Transportation 400 7th Street SW

Dear Sir:

I was referred to your office by the people at the D.O.T. 1-800 number as the source for an NHTSA legal opinion concerning an automotive accessory product I have developed. Since one of its functions is somewhat related to the third brakelight now requir ed in 1986 or newer automobiles, but no reference to its total concept is made in Regulation 108, I feel its necessary we have an official opinion on any potential current or future legal problems that might arise when this product is marketed.

I have included a complete functional description of the product as we now intend to manufacture It and I Hill certainly appreciate any suggestions or comments you might have and any reference to other NHTSA regulations that define a product concept like VISICOM if any exist at all.

Thanking you in advance I remain:

Sincerely

Fred E. Maynard 13208 Creek Park Lane Poway, Ca. 92064 (619) 748 5883

VISICOM-Product Description

The VISICOM concept can best be described as an electronic sign or message sending unit. It has a number of potential applications with the most attractive market being that of an automotive accessory. In this configuration It will be sold with a number of preprogrammed words and messages the primary purpose of which will be to enhance the safety aspects of automobile operation and promote a higher degree of courtesy on the road.

Physically the unit comes in two sections. the control panel which mounts on the dashboard of the vehicle, and the display section which is to be positioned in the center of the rear window. According to NHTSA (National Highway Traffic Safety Administrat ion) guidelines, a third brakelight would be located in this area of the vehicle in 1986 or newer cars so in order to avoid any conflict with these regulations, the VISICOM automotive model will be supplied with an integrated third brake light which will meet all of the standards required by NHTSA regulation 108 as to size, light intensity, angle of visibility, etc.. This third brakelight will also serve as the base for the display section of the VISICOM which measures approximately 4"H x 17"L x 3"D. Th is enclosure contains virtually all of the electronic control and programming circuits as well as the display itself which consists of six 14 segment alpha-numeric characters 2.5"W x 3.9 "H. Each segment contains a 1.2 watt incandescent bulb which is ene rgized when that segment is required to form a specific number or letter. The words formed by the segmented characters are displayed one at a time for a duration of the seconds with a half second pause in between until the message is complete. Some of th e messages are automatically activated and some of the others continue repeating until the operator ceases the transmission. The messages contained in the system are as follows:

Automatic Messages One Time Display Messages

1. STOP 1. HELLO 2. TURN ------ 2. THANK YOU 3. TURN ------ 3. HAVE A NICE DAY 4. BACKUP 4. SORRY 5. BYEBYE Driver Activated Repeating 6. OK TO PASS Messages 7. NOT OK TO PASS 8. PLEASE DIM YOUR LIGHTS 1. PLEASE CALL POLICE 9. YOU ARE TOO CLOSE 2. NEED HELP 10. CHILD IN CAR 3. HAZARD AHEAD 11. CHECK YOUR DOORS 4. OUT OF GAS 12. CHECK YOUR TIRES

ID: 7577

Mr. J. W. Lawrence
Manager, Compliance and Technical Legislation
Volvo GM Heavy Truck Corporation
P.O. Box 26115
Greensboro, NC 27402-6115

Dear Mr. Lawrence:

This responds to your March 5, 1992 letter to the Administrator on the subject "Petition for Rulemaking - FMVSS 108 Turn Signal Installation Requirements."

In that letter, Volvo GM petitioned "for the revocation of the 'Figure 2' requirements published in the December 12, 1991, Register. . . ." However, the notice published on that date (56 FR 64733) was not an amendment of Federal Motor Vehicle Safety Standard No. 108. Instead, it was only a denial of a petition for rulemaking to allow tail lamps on vehicles 80 inches or wider to be mounted at locations up to 24 inches forward of the extreme rear of the vehicle, and to allow turn signal and stop lamps to be mounted up to 60 inches forward of the rear instead of "on the rear" as required by Standard No. 108. Paragraph S5.3.1.1 of Standard No. 108 expresses the general requirement that lamps be located so as to meet the visibility requirements specified in any applicable SAE standard. Figure 2 was included in the notice to illustrate the agency's interpretation of the visibility requirements for stop, tail, and turn signal lamps set forth in specific SAE vehicle lighting standards incorporated by reference in Standard No. 108. A copy of that figure is enclosed. However, Figure 2 is not incorporated into Standard No. 108 itself.

Since Figure 2 is not part of Standard No. 108, a petition for rulemaking is not the appropriate way to address the problem you have raised. Accordingly, we are treating your letter as a request to change our interpretation of the SAE's specifications. As explained below, the agency is adopting a new interpretation that is consistent with your concerns and arguments.

The rationale for the agency's denial of the petition was that the amendments requested would adversely affect the ability of the lamps to meet the SAE specifications incorporated into Standard No. 108 that the lamps on both sides of a vehicle's rear end be simultaneously visible from any angle between and including 45-degree angles to the rear left and right of the vehicle. As noted above, Figure 2 pictorially represents NHTSA's interpretation of the SAE's uniform geometric visibility requirements. Using the SAE standard for turn signal lamps on wide vehicles as an example, NHTSA provided the following quotation from J1395:

"Signals from lamps on both sides of the vehicle shall be visible through a horizontal angle from 45 deg. to the left for the left lamp to 45 deg. to the right for the right lamp. * * * To be considered visible, the lamp must provide an unobstructed view of the outer lens surface, excluding reflex of at least 13 sq. cm. measured at 45 deg. to the longitudinal axis of the vehicle."

Since the SAE measurement of photometry is made at a distance of 3 meters from the lamp, NHTSA also stated that compliance with the visibility requirements is to be determined at a distance of 3 meters.

NHTSA's interpretation of the SAE language quoted above, which Figure 2 illustrates, and which you have found objectionable, was:

"Thus, the turn signals on both sides of the vehicle must be simultaneously visible through a horizontal angle from 45 degrees originating at the left lamp, to the left to 45 degrees to the right originating at the right lamp measured at a radius of 3 meters."

You state that the term "simultaneously visible" does not appear in the SAE specifications. You also argue that the 3 meter requirement has no connection to the 45-degree installation visibility. These issues have also been raised with us by the Motor Vehicle Manufacturers Association (MVMA), which met with us to express its views, not only on turn signal lamps, but stop and tail lamps as well, and by Ford Motor Company, and Freightliner, Corp. in several telephone calls. We are furnishing copies of this response to these three parties, as well as to the original petitioner, Truck Trailer Manufacturers Association (TTMA).

First of all, let me assure you that NHTSA had no intention of imposing any new requirements upon industry in its interpretation reflected in Figure 2, and that the reaction of industry to this interpretation came as a surprise to us. Although your letter concerns only the turn signal specifications for wide vehicles, we have reviewed this matter with respect to tail lamps and stop lamps as well, given the concern of other industry members.

Our review has led us to place added weight on the fact that the SAE visibility requirements are not consistently expressed from SAE standard to SAE standard. This difference in expression particularly calls into question our interpretation regarding turn signals. This same difference has led MVMA to apply one interpretation to turn signals, and another to stop and tail lamps. We shall discuss these two interpretations separately, and compare them with NHTSA's single, across-the-board interpretation. Under NHTSA's interpretation, the minimum specified lens area of a left stop, turn signal, or tail lamp, as seen at 45 degrees to the left of that lamp, must also be seen at 45 degrees to the right of the right lamp, and at all degrees in between (and vice versa) when viewed at a 3-meter radius from the rear.

As suggested above, MVMA does not believe that an across- the-board interpretation is appropriate, given the different expression of the turn signal specification for vehicles in J1395 and J588. SAE J1395 provides that visibility is "from 45 deg. to the left for the left lamp to 45 deg. to the right for the right lamp." (Emphasis added.) The first underlined passage suggests that the viewing angle is a left 45 deg. angle, using a line parallel to the vehicle longitudinal axis as the frame of reference for that angle, and that this viewing angle relates to the left signal lamp only. The passage says that the angle is 45 deg. to the left "for" the left lamp, and not 45 deg. to the left of that lamp. The second underlined passage indicates a similar limitation on the applicability of the language regarding the 45 deg. angle to the right. Even more specific is the corresponding requirement in SAE J588 NOV84, Standard No. 108's specification for turn signals on vehicles less than 80 inches wide. It provides: "signals from lamps mounted on the left side of the vehicle shall be visible through a horizontal angle of 45 deg. to the left and signals from lamps mounted on the right side of the vehicle shall be visible through a horizontal angle of 45 deg. to the right." For both wide and narrow vehicles, MVMA interprets the 45 degree left visibility requirement as applying only to the outboard side of the left turn signal lamp, and a 45 degree right visibility requirement only to the outboard side of the right turn signal lamp. NHTSA agrees that MVMA's interpretation regarding turn signal lamps is more fully consistent than NHTSA's interpretation with the language of these SAE standards. Adopting this interpretation moots the question of the particular distance at which visibility is to be determined. However, the fact that the SAE standard did not specify a measurement distance tends to strengthen the case for the MVMA interpretation since its interpretation obviates the need for a measurement distance, while the former NHTSA interpretation necessitated one. The MVMA and TTMA interpretations of the stop and tail lamp requirements are less clearly superior to NHTSA's in their faithfulness to the language of the SAE standards. Indeed, whether any of the competing interpretations is superior in this regard is harder to assess because the language regarding these lamps is more ambiguous. The SAE specifications for stop and tail lamps, incorporated in Standard No. 108, are respectively J586 FEB84 (narrow vehicles) and J1398 MAY85 (wide vehicles), and J585e Sept. 1977. Under all three of these SAE standards, "signals from lamps on both sides of the vehicle shall be visible through a horizontal angle", which is specified as "of 45 deg. to the left and to 45 deg. to the right" (J586), "of 45 deg. to the left to 45 deg. to the right" (J1398), and "from 45 deg. to the left to 45 deg. to the right" (J585e).

TTMA and MVMA restrict the left-right 45 degree visibility requirement to the individual lamp in a horizontal plane, as shown in Figure 1 of the December 1991 notice. Under this interpretation, the minimum specified lens area that is seen at 45 degrees to the left on the left lamp must be seen at 45 degrees to the right of the left lamp, but need not be seen at 45 degrees to the right of the right lamp (and vice versa). In MVMA's view, there was never an intent by the SAE to expect that the minimum lens area of both lamps would be visible from both sides of the vehicle. MVMA also argued that there was no justification to use the photometric measuring distance of 3 meters to determine visibility.

Some aspects of the SAE standards regarding stop and tail lamps seem to favor the MVMA/TTMA interpretation, while others favor the NHTSA interpretation. For example, if these SAE standards are interpreted in light of the interpretation given above to the SAE turn signal requirements, then those stop and tail lamp standards will be interpreted as specifying angles of visibility whose frame of reference is each individual lamp instead of the vehicle as a whole. As in the case of the turn signal requirement, the absence of a specified measurement distance for stop and tail lamp visibility tends to support an interpretation that does not depend on such a distance being specified. On the other hand, the absence of any language, like that found in J1395, relating the angle or angles of visibility to any individual lamp, suggests a single continuous horizontal angle spanning the entire rear of a vehicle.

NHTSA has decided to adopt the TTMA/MVMA interpretation of the stop and tail lamp visibility requirements. We have said that NHTSA did not intend to impose new burdens on industry by its interpretation, and there appears to be no present safety justification to do so. The existing level of rear lighting safety on the nation's roads is that which is represented by industry's interpretation of the SAE visibility requirements. Thus, there would be no derogation of the existing level of safety by concurring with an industry interpretation. Further, given the lack of clear support for either of the competing interpretations, any attempt by NHTSA to apply its former interpretation to enforce these requirements in a court of law could be very problematic.

This letter will serve as notice to the industry that the agency will follow the interpretations stated herein in its future enforcement activities. The SAE visibility materials do not specify any measurement distance. Therefore, to carry the new interpretation to its proper conclusion, NHTSA is no longer specifying a measurement distance of 3 meters to judge compliance with the visibility requirements. Industry and NHTSA are both in agreement, however, that, wherever located, any of these lamps are required by S5.3.1.1 to continue to meet its photometric output at any applicable group of test points, unless excepted by the subsequent conditions of that paragraph.

Finally, you comment that Table II "does not require the turn signals be located on the rear except for trailers". We do not understand your remark since Table II clearly specifies that turn signal lamps be located on the rear of all vehicles to which the Table applies, and not trailers alone.

Sincerely,

Paul Jackson Rice Chief Counsel

Enclosure

cc: Motor Vehicle Manufacturers Association Truck Trailer Manufacturers Association Ford Motor Company Freightliner Corp.

ref:108 d:10/5/92

ID: nht92-3.25

DATE: October 5, 1992

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: J. W. Lawrence -- Manager, Compliance and Technical Legislation, Volvo GM Heavy Truck Corporation

COPYEE: Motor Vehicle Manufacturers Association; Truck Trailer Manufacturers Association; Ford Motor Company; Freightliner Corp.

TITLE: None

ATTACHMT: Attached to letter dated 3/5/92 from J. W. Lawrence to Administrator, NHTSA (9203090012)

TEXT:

This responds to your March 5, 1992 letter to the Administrator on the subject "Petition for Rulemaking - FMVSS 108 Turn Signal Installation Requirements."

In that letter, Volvo GM petitioned "for the revocation of the 'Figure 2' requirements published in the December 12, 1991, Register. . . ." However, the notice published on that date (56 FR 64733) was not an amendment of Federal Motor Vehicle Safety Standard No. 108. Instead, it was only a denial of a petition for rulemaking to allow tail lamps on vehicles 80 inches or wider to be mounted at locations up to 24 inches forward of the extreme rear of the vehicle, and to allow turn signal and stop lamps to be mounted up to 60 inches forward of the rear instead of "on the rear" as required by Standard No. 108. Paragraph S5.3.1.1 of Standard No. 108 expresses the general requirement that lamps be located so as to meet the visibility requirements specified in any applicable SAE standard. Figure 2 was included in the notice to illustrate the agency's interpretation of the visibility requirements for stop, tail, and turn signal lamps set forth in specific SAE vehicle lighting standards incorporated by reference in Standard No. 108. A copy of that figure is enclosed. However, Figure 2 is not incorporated into Standard No. 108 itself.

Since Figure 2 is not part of Standard No. 108, a petition for rulemaking is not the appropriate way to address the problem you have raised. Accordingly, we are treating your letter as a request to change our interpretation of the SAE's specifications. As explained below, the agency is adopting a new interpretation that is consistent with your concerns and arguments.

The rationale for the agency's denial of the petition was that the amendments requested would adversely affect the ability of the lamps to meet the SAE specifications incorporated into Standard No. 108 that the lamps on both sides of a vehicle's rear end be simultaneously visible from any angle between and including 45-degree angles to the rear left and right of the vehicle. As noted above, Figure 2 pictorially represents NHTSA's interpretation of the SAE's uniform geometric visibility requirements. Using the SAE standard for turn signal lamps on wide vehicles as an example, NHTSA provided the following quotation from J1395:

"Signals from lamps on both sides of the vehicle shall be visible through a horizontal angle from 45 deg. to the left for the left lamp to 45 deg. to

the right for the right lamp. *** To be considered visible, the lamp must provide an unobstructed view of the outer lens surface, excluding reflex of at least 13 sq. cm. measured at 45 deg. to the longitudinal axis of the vehicle."

Since the SAE measurement of photometry is made at a distance of 3 meters from the lamp, NHTSA also stated that compliance with the visibility requirements is to be determined at a distance of 3 meters.

NHTSA's interpretation of the SAE language quoted above, which Figure 2 illustrates, and which you have found objectionable, was:

"Thus, the turn signals on both sides of the vehicle must be simultaneously visible through a horizontal angle from 45 degrees originating at the left lamp, to the left to 45 degrees to the right originating at the right lamp measured at a radius of 3 meters."

You state that the term "simultaneously visible" does not appear in the SAE specifications. You also argue that the 3 meter requirement has no connection to the 45-degree installation visibility. These issues have also been raised with us by the Motor Vehicle Manufacturers Association (MVMA), which met with us to express its views, not only on turn signal lamps, but stop and tail lamps as well, and by Ford Motor Company, and Freightliner, Corp. in several telephone calls. We are furnishing copies of this response to these three parties, as well as to the original petitioner, Truck Trailer Manufacturers Association (TTMA).

First of all, let me assure you that NHTSA had no intention of imposing any new requirements upon industry in its interpretation reflected in Figure 2, and that the reaction of industry to this interpretation came as a surprise to us. Although your letter concerns only the turn signal specifications for wide vehicles, we have reviewed this matter with respect to tail lamps and stop lamps as well, given the concern of other industry members.

Our review has led us to place added weight on the fact that the SAE visibility requirements are not consistently expressed from SAE standard to SAE standard. This difference in expression particularly calls into question our interpretation regarding turn signals. This same difference has led MVMA to apply one interpretation to turn signals, and another to stop and tail lamps. We shall discuss these two interpretations separately, and compare them with NHTSA's single, across-the-board interpretation. Under NHTSA's interpretation, the minimum specified lens area of a left stop, turn signal, or tail lamp, as seen at 45 degrees to the left of that lamp, must also be seen at 45 degrees to the right of the right lamp, and at all degrees in between (and vice versa) when viewed at a 3-meter radius from the rear.

As suggested above, MVMA does not believe that an across-the-board interpretation is appropriate, given the different expression of the turn signal specification for vehicles in J1395 and J588. SAE J1395 provides that visibility is "from 45 deg. to the left for the left lamp to 45 deg. to the right for the right lamp." (Emphasis added.) The first underlined passage suggests that the viewing angle is a left 45 deg. angle, using a line parallel to the vehicle longitudinal axis as the frame of reference

for that angle, and that this viewing angle relates to the left signal lamp only. The passage says that the angle is 45 deg. to the left "for" the left lamp, and not 45 deg. to the left of that lamp. The second underlined passage indicates a similar limitation on the applicability of the language regarding the 45 deg. angle to the right. Even more specific is the corresponding requirement in SAE J588 NOV84, Standard No. 108's specification for turn signals on vehicles less than 80 inches wide. It provides: "signals from lamps mounted on the left side of the vehicle shall be visible through a horizontal angle of 45 deg. to the left and signals from lamps mounted on the right side of the vehicle shall be visible through a horizontal angle of 45 deg. to the right."

For both wide and narrow vehicles, MVMA interprets the 45 degree left visibility requirement as applying only to the outboard side of the left turn signal lamp, and a 45 degree right visibility requirement only to the outboard side of the right turn signal lamp. NHTSA agrees that MVMA's interpretation regarding turn signal lamps is more fully consistent than NHTSA's interpretation with the language of these SAE standards. Adopting this interpretation moots the question of the particular distance at which visibility is to be determined. However, the fact that the SAE standard did not specify a measurement distance tends to strengthen the case for the MVMA interpretation since its interpretation obviates the need for a measurement distance, while the former NHTSA interpretation necessitated one.

The MVMA and TTMA interpretations of the stop and tail lamp requirements are less clearly superior to NHTSA's in their faithfulness to the language of the SAE standards. Indeed, whether any of the competing interpretations is superior in this regard is harder to assess because the language regarding these lamps is more ambiguous. The SAE specifications for stop and tail lamps, incorporated in Standard No. 108, are respectively J586 FEB84 (narrow vehicles) and J1398 MAY85 (wide vehicles), and J585e Sept. 1977. Under all three of these SAE standards, "signals from lamps on both sides of the vehicle shall be visible through a horizontal angle", which is specified as "of 45 deg. to the left and to 45 deg. to the right" (J586), "of 45 deg. to the left to 45 deg. to the right" (J1398), and "from 45 deg. to the left to 45 deg. to the right" (J585e).

TTMA and MVMA restrict the left-right 45 degree visibility requirement to the individual lamp in a horizontal plane, as shown in Figure 1 of the December 1991 notice. Under this interpretation, the minimum specified lens area that is seen at 45 degrees to the left on the left lamp must be seen at 45 degrees to the right of the left lamp, but need not be seen at 45 degrees to the right of the right lamp (and vice versa). In MVMA's view, there was never an intent by the SAE to expect that the minimum lens area of both lamps would be visible from both sides of the vehicle. MVMA also argued that there was no justification to use the photometric measuring distance of 3 meters to determine visibility.

Some aspects of the SAE standards regarding stop and tail lamps seem to favor the MVMA/TTMA interpretation, while others favor the NHTSA interpretation. For example, if these SAE standards are interpreted in light of the interpretation given above to the SAE turn signal requirements, then those stop and tail lamp standards will be interpreted as specifying

angles of visibility whose frame of reference is each individual lamp instead of the vehicle as a whole. As in the case of the turn signal requirement, the absence of a specified measurement distance for stop and tail lamp visibility tends to support an interpretation that does not depend on such a distance being specified. On the other hand, the absence of any language, like that found in J1395, relating the angle or angles of visibility to any individual lamp, suggests a single continuous horizontal angle spanning the entire rear of a vehicle.

NHTSA has decided to adopt the TTMA/MVMA interpretation of the stop and tail lamp visibility requirements. We have said that NHTSA did not intend to impose new burdens on industry by its interpretation, and there appears to be no present safety justification to do so. The existing level of rear lighting safety on the nation's roads is that which is represented by industry's interpretation of the SAE visibility requirements. Thus, there would be no derogation of the exiting level of safety by concurring with an industry interpretation. Further, given the lack of clear support for either of the competing interpretations, any attempt by NHTSA to apply its former interpretation to enforce these requirements in a court of law could be very problematic.

This letter will serve as notice to the industry that the agency will follow the interpretations stated herein in its future enforcement activities. The SAE visibility materials do not specify any measurement distance. Therefore, to carry the new interpretation to its proper conclusion, NHTSA is no longer specifying a measurement distance of 3 meters to judge compliance with the visibility requirements. Industry and NHTSA are both in agreement, however, that, wherever located, any of these lamps are required by S5.3.1.1 to continue to meet its photometric output at any applicable group of test points, unless excepted by the subsequent conditions of that paragraph.

Finally, you comment that Table II "does not require the turn signals be located on the rear except for trailers". We do not understand your remark since Table II clearly specifies that turn signal lamps be located on the rear of all vehicles to which the Table applies, and not trailers alone.

ID: nht93-5.36

TYPE: Interpretation-NHTSA

DATE: July 29, 1993

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Ray M. Miyamoto

TITLE: None

ATTACHMT: Attached to letter dated 6/19/93 from Ray M. Miyamoto to Public Community Strategy, NHTSA (OCC 8840)

TEXT:

This responds to your letter on June 19, 1993, requesting permission to retrofit older cars with air bags. I am pleased to have this opportunity to explain our laws and regulations to you.

The National Traffic and Motor Vehicle Safety Act (the Safety Act; 15 U.S.C. 1381 et seq.) authorizes this agency to issue Federal motor vehicle safety standards applicable to new motor vehicles and new items of motor vehicle equipment. NHTSA has exercised this authority to issue Standard No. 208, Occupant Crash Protection (49 CFR S571.208). Among other things, Standard No. 208 requires that cars be equipped with automatic crash protection. Light trucks will also be required to provide automatic crash protection, beginning with the 1995 model year. "Automatic crash protection" means that a vehicle is equipped with occupant restraints that require no action by vehicle occupants. The performance of automatic crash protection is dynamically tested, that is, the automatic systems are required to comply with certain injury reduction criteria as measured by test dummies in a barrier crash test at speeds up to 30 mph. The two types of automatic crash protection currently offered are automatic safety belts (which help to assure belt use) and air bags (which supplement safety belts and offer some protection even when safety belts are not used.) A new Federal statutory requirement will make air bags mandatory in all new cars and light trucks by the late 1990's.

After the first purchase of a vehicle, the only provision in Federal law that affects a vehicle's continuing compliance with an applicable safety standard is set forth in section 108(a)(2)(A) of the Safety Act (15 U.S.C. 1397(a)(2)(A)). That section provides:

No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or in part, any device or element of design installed on or in a motor vehicle ... in compliance with an applicable Federal motor vehicle safety standard.

This "render inoperative" provision would prohibit you, as a commercial repair business, from installing an aftermarket air bag in a manner that would negatively affect the vehicle's compliance with any applicable safety standard. This provision does not require you to ensure that the vehicle would have complied with Standard No. 208 if the air bag had been installed in the vehicle as original equipment, it only requires you to ensure that the installation does not "render inoperative" any of the devices or design elements which were installed as original equipment. You do not need to receive permission from NHTSA prior to opening your business, however, any violations of the "render inoperative" prohibition would subject you to a potential civil penalty of up to $1,000 for each violation. In addition, you may wish to consult state law concerning liability if you retrofit vehicles with air bags.

Given the safety benefits that air bags are now providing, we understand that many persons desire that air bags be made available to be retrofitted in vehicles which were not originally equipped with this life-saving device. However, this concept poses enormous engineering challenges. New car manufacturers design air bag systems for the car in which it is installed. In designing the air bag system, air bag size, shape, venting and inflator gas generation characteristics are predicated on the specific car interior, taking into consideration such factors as the seats, steering-column crush stroke force resistance, gage array and location on instrument panel, location and nature of knee bolsters, and compartment acceleration responses in frontal crashes.

It is highly unlikely that a retrofit system for older cars can be devised that could provide the safety and functional characteristics of current new car systems which are integrated into car design from inception. Moreover, unless an air bag system was designed in light of the specific characteristics of the vehicle for which it was intended, it is possible that the air bag might not provide any safety benefits in a crash, or even create a safety problem (e.g., if it activated under inappropriate circumstances). I am enclosing a copy of an article from the April 29, 1993, Washington Post which also discusses the difficulties in installing air bags in used cars.

NHTSA is aware, however, that at least one major air bag manufacturer, Breed Automotive, is attempting to develop retrofit air bag systems for certain popular cars, trucks, and vans which were produced without driver air bags in the last few years. If you desire further information about this program at that company, Mr. William Textores (201) 299-6500 may be willing to provide you with such information. I must emphasize, however, that NHTSA does not endorse any commercial products.

I have also enclosed an information sheet that identifies relevant Federal statutes and NHTSA standards and regulations affecting motor vehicle and motor vehicle equipment manufacturers, and explains how to obtain copies of these materials.

I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992.

ID: 8840

Mr. Ray M. Miyamoto
Apt. B-407
95-2055 Waikalani Pl.
Mililani, HI 96789

Dear Mr. Miyamoto:

This responds to your letter on June 19, 1993, requesting permission to retrofit older cars with air bags. I am pleased to have this opportunity to explain our laws and regulations to you.

The National Traffic and Motor Vehicle Safety Act (the Safety Act; 15 U.S.C. 1381 et seq.) authorizes this agency to issue Federal motor vehicle safety standards applicable to new motor vehicles and new items of motor vehicle equipment. NHTSA has exercised this authority to issue Standard No. 208, Occupant Crash Protection (49 CFR 571.208). Among other things, Standard No. 208 requires that cars be equipped with automatic crash protection. Light trucks will also be required to provide automatic crash protection, beginning with the 1995 model year. "Automatic crash protection" means that a vehicle is equipped with occupant restraints that require no action by vehicle occupants. The performance of automatic crash protection is dynamically tested, that is, the automatic systems are required to comply with certain injury reduction criteria as measured by test dummies in a barrier crash test at speeds up to 30 mph. The two types of automatic crash protection currently offered are automatic safety belts (which help to assure belt use) and air bags (which supplement safety belts and offer some protection even when safety belts are not used.) A new Federal statutory requirement will make air bags mandatory in all new cars and light trucks by the late 1990's.

After the first purchase of a vehicle, the only provision in Federal law that affects a vehicle's continuing compliance with an applicable safety standard is set forth in section 108(a)(2)(A) of the Safety Act (15 U.S.C. 1397(a)(2)(A)). That section provides:

No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or in part, any device or element of design installed on or in a motor vehicle ... in compliance with an applicable Federal motor vehicle safety standard.

This "render inoperative" provision would prohibit you, as a commercial repair business, from installing an aftermarket air bag in a manner that would negatively affect the vehicle's compliance with any applicable safety standard. This provision does not require you to ensure that the vehicle would have complied with Standard No. 208 if the air bag had been installed in the vehicle as original equipment, it only requires you to ensure that the installation does not "render inoperative" any of the devices or design elements which were installed as original equipment. You do not need to receive permission from NHTSA prior to opening your business, however, any violations of the "render inoperative" prohibition would subject you to a potential civil penalty of up to $1,000 for each violation. In addition, you may wish to consult state law concerning liability if you retrofit vehicles with air bags.

Given the safety benefits that air bags are now providing, we understand that many persons desire that air bags be made available to be retrofitted in vehicles which were not originally equipped with this life-saving device. However, this concept poses enormous engineering challenges. New car manufacturers design air bag systems for the car in which it is installed. In designing the air bag system, air bag size, shape, venting and inflator gas generation characteristics are predicated on the specific car interior, taking into consideration such factors as the seats, steering column crush stroke force resistance, gage array and location on instrument panel, location and nature of knee bolsters, and compartment acceleration responses in frontal crashes.

It is highly unlikely that a retrofit system for older cars can be devised that could provide the safety and functional characteristics of current new car systems which are integrated into car design from inception. Moreover, unless an air bag system was designed in light of the specific characteristics of the vehicle for which it was intended, it is possible that the air bag might not provide any safety benefits in a crash, or even create a safety problem (e.g., if it activated under inappropriate circumstances). I am enclosing a copy of an article from the April 29, 1993, Washington Post which also discusses the difficulties in installing air bags in used cars.

NHTSA is aware, however, that at least one major air bag manufacturer, Breed Automotive, is attempting to develop retrofit air bag systems for certain popular cars, trucks, and vans which were produced without driver air bags in the last few years. If you desire further information about this program at that company, Mr. William Textores (201) 299-6500 may be willing to provide you with such information. I must emphasize, however, that NHTSA does not endorse any commercial products.

I have also enclosed an information sheet that identifies relevant Federal statutes and NHTSA standards and regulations affecting motor vehicle and motor vehicle equipment manufacturers, and explains how to obtain copies of these materials.

I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992.

Sincerely,

John Womack Acting Chief Counsel

Enclosures

ref:208 d:7/29/93

ID: nht76-3.26

DATE: 03/15/76

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: NAFDEM

TITLE: FMVSR INTERPRETATION

TEXT: This is in response to your letter of January 26, 1976, concerning procedures for the certification of trucks on which your member companies mount tanks for the transportation of food and dairy products. The letter requested our review of six procedures agreed to by your members for compliance with the Federal certification requirements. The procedures are restated below along with our comments.

1. "Member companies agree to assume the responsibility for notification and instruction of customers to select a truck chassis with a loaded and axle capacity rating equal to or exceeding the total weight of the completed truck chassis, i.e., chassis, tank, and payload, in order to comply with Federal safety standards."

We encourage this practice. Please note, however, that the customer himself has no duty under the National Traffic and Motor Vehicle Safety Act of 1966, as amended ("the Act"), the Federal motor vehicle safety standards, or applicable regulations, to select a chassis with sufficient load ratings. The duty is your member companies', when presented with chassis of insufficient load ratings, to refrain from mounting tanks.

2. "Member companies agree to assume the responsibility for notification and instruction of a customer when his new vehicle is received to obtain an incomplete vehicle certification supplied by the truck manufacturer, and to retain this certification in the truck cab until his tank is mounted as a complete unit."

Assuming that by "incomplete vehicle certification supplied by the truck manufacturer" you mean the document referred to in @ 568.4 of 49 CFR Part 568, Vehicles Manufactured in Two or More Stages, we encourage this practice as well. Please note once again, however, that the customer has no duty under applicable law to obtain or retain the document. Provision of the document is the duty of the chassis manufacturer. While your members are free to require of their customers the obtaining and retention of the document, this would be a solely contractual requirement.

3. "In the event that the customer has the chassis altered by an intermediate party such as lengthening the frame, adding an axle, or changing tire size and/or specifications, member companies agree to advise the customer of his responsibility for obtaining from the intermediate shop a certificate stating the new gross vehicle weight rating and new gross axle weight rating, and that the vehicle complies with all Federal motor vehicle safety standards."

This does not correctly state the applicable law, for the reasons discussed in #2 above. Pursuant to @ 568.5, it is the duty of the intermediate manufacturer to pass on the incomplete vehicle document. The customer's duty is a matter of private contract. Further, the incomplete vehicle document need not certify that the chassis complies with all Federal motor vehicle safety standards. It must simply provide the statements and information set out in @ 568.4(a), with such addendum as may be necessary.

4. "The member company, as a transportation tank manufacturer, at the time of mounting the customer's tank on the new truck chassis at his plant, will be responsible to certify through the preparation of a completed vehicle certification that the unit complies with requirements set forth by the National Highway Traffic Safety Administration."

That is correct.

5. "When a new truck chassis is received at a member company's plant for mounting with no or improper "incomplete vehicle certification" documents, the vehicle will be certified for "no load" carrying capacity."

This practice is improper. A vehicle may not be certified for "no load" carrying capacity. @ 567.5 of 49 CFR Part 567, Certification, requires that Gross Vehicle Weight Rating (GVWR) and Gross Axle Weight Ratings (GAWR's) be stated, @ 567.5(a)(5) explicity provides that the GVWR:

shall not be less than the sum of the unloaded vehicle weight, rated cargo load, and 150 pounds times the vehicle's designated seating capacity. . .

Further, where your member company mounts a tank that is designed to carry a particular commodity, the rated cargo load on which he bases the ratings should not be less than what he can reasonably expect the user to consider a "full load" of that commodity. The incomplete vehicle document is designed to protect the final stage manufacturer in his certification of the completed vehicle.

6. "When the gross vehicle weight ratings or gross vehicle axle ratings are less than the required rating for the capacity of the tank, the member company will state the limited carrying capacity to meet Federal standards on the certification document."

For the reasons discussed in #5 above, this practice is not necessarily proper. In particular, if it is reasonable to expect that the user will load the vehicle to its full volumetric capacity despite your member company's specification on the certification plate of a "limited carrying capacity", then the vehicle would probably be considered to contain a safety-related defect, subject to the notification and remedy provisions of the Act.

If you have any further questions, please feel free to write.

ID: 77-3.48

TYPE: INTERPRETATION-NHTSA

DATE: 08/18/77

FROM: AUTHOR UNAVAILABLE; Joseph J. Levin Jr.; NHTSA

TO: Walker Stainless Equipment Co.

TITLE: FMVSR INTERPRETATION

ATTACHMT: 5/11/77 Letter from Walker Stainless Equipment Co. to NHTSA

TEXT: This is in response to your letter of May 11, 1977, and your subsequent conversation with Roger Tilton of my staff, concerning the certification of tank type vehicles. You suggest that a vehicle certification label as specified in 49 CFR Part 567, Certification, be required to state the gross vehicle weight rating (GVWR) and the gross axle weight rating (GAWR) in pounds.

You apparently have misinterpreted our regulations to require that the GVWR and the GAWR be in something other than pounds where a vehicle is designed to carry liguids. Since the density of liquids is not constant, the weight of customary liquid measurements would depend upon the type of liquid being carried. Since liquid measurements have no precise weight value, designating load ratings by those measurements would not ensure that vehicles would not be overloaded. It has always been the policy of the National Highway Traffic Safety Administration to require that the GAWR and the GVWR be stated in pounds.

Title 49 CFR Part 568 prescribes the method by which manufacturers of vehicles manufactured in two or more stages must ensure conformity with the Federal motor vehicle safety standards. A final-stage manufacturer is described as one who "performs such manufacturing operations on an incomplete vehicle that it becomes a completed vehicle." Both "incomplete vehicle" and "completed vehicle" are defined in Section 568.3 of the regulation.

Section 568.6 of Title 49 requires each final-stage manufacturer to certify that the entire vehicle conforms to all applicable standards, in accordance with Section 567.5. That section requires each final-stage manufacturer to affix a label to the vehicle containing, among other things, the GVWR and the GAWR. The GVWR is the value in pounds, which is not less than the sum of the unloaded vehicle weight, rated cargo load, and 150 pounds times the vehicle's designated seating capacity. The GAWR is the value specified by the vehicle manufacturer as the load-carrying capacity of a single axle system, as measured at the tire-ground interfaces.

When a vehicle is manufactured in two or more stages 49 CFR 568.4 requires the incomplete manufacturer to furnish with the incomplete vehicle a document containing the GVWR and GAWR for the completed vehicle for which the incomplete vehicle is intended. These ratings are generally used by the final-stage manufacturer in certifying the vehicle. If he chooses to exceed the stated GVWR and GAWR ratings he must also certify that the vehicle will continue to meet all applicable motor vehicle safety standards.

It is the cargo load rating that is most relevant to the problem of overloading. The rated cargo load should represent the manufacturer's assessment of the vehicle's cargo-carrying capacity and the maximum load at which the vehicle may be safety operated. A manufacturer must consider the maximum load capacity of the vehicle when it designs its cargo-carrying portion. If this is not done, the rated cargo load, and thus the GVWR, may be meaningless since the vehicle may have a cargo-carrying chamber which, if filled, would cause the vehicle to exceed its stated weight ratings. An illustration of such a situation would be a tanker truck which exceeds its GVWR when the tank is filled with a type of material appropriate for carrying in that cargo area. If the manufacturer could reasonably have anticipated that such cargo would be carried in the tanker, yet rated the vehicle with a GVWR which was less than the vehicle's weight when fully loaded with that cargo, a safety-related defect for which the manufacturer is responsible may be considered to exist.

The NHTSA does not expect manufacturers to be omniscient when it comes to the use of the vehicles they produce. It does, however, except the stated weight ratings to reflect the design of the vehicles and the uses to which they can reasonably be anticipated to be put. Where the manufacturer has reason to know the specific commodity intended to be carried in its vehicles and those vehicles have a totally enclosed cargo area, as with a tanker, the rated cargo load is relatively easy to determine.

In your particular case, your responsibility for any subsequent overloading of the vehicles you manufacture would be determined by the reasonableness of your GVWR's and GAWR's, given the size and configuration of your vehicles and the types of loads which they could reasonably be expected to carry. In the case of flat beds (no enclosed cargo area) a manufacturer would obviously not be able to provide weight ratings sufficiently high to prevent over-loading in all instances. The design of flat beds necessarily permits overloading since the cargo area is unrestricted. Thus if the weight ratings specified appear to have been arrived at by a good faith determination based upon the types of loads the manufacturer anticipates will be carried, its responsibility with regard to weight rating specifications will have been satisfied and no safety-related defect will be attributable to it.