ID: nht73-3.23

DATE: 02/12/73

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

TO: Rubber Manufacturers Association

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of January 5, 1973, to Dr. Edward H. Wallace, concerning your objections to the informal rulemaking procedures employed by NHTSA in adding new tire sizes and rims to the Appendices to Federal Motor Vehicle Safety Standards Nos. 109 and 110 (49 CFR 571.109, 110). You enclose two form letters sent to you by NHTSA which indicate that certain tire sizes and rims will be included in the Appendices, and object to the delay that appears to occur between your receipt of these letters and the time the amendment to the Appendices is published in the Federal Register.

Your letter indicates a possible misunderstanding of the requirements applicable to rulemaking procedures, and how these requirements affect the publication of new tire sizes and rims in the Appendices of the two safety standards.

The NHTSA is required, under the Administrative Procedures Act (5 U.S.C. 551 et seq.), to amend all motor vehicle safety standards (amendments to the appendices of Standards Nos. 103 and 110 are amendments to the standards) by publication in the Federal Register. The submittal of documents to the Federal Register is governed by regulation (Title 1 of the Code of Federal Regulations, Parts 1 - 40) which the NHTSA must follow in submitting documents for publication. Simply stated, these regulations would not permit the NHTSA to merely send to the Federal Register copies of these acknowledgment letters, for publication, as you suggest. Documents must be prepared utilizing a specific format. We have recently modified the method by which NHTSA amends the Appendices in a way that permits these documents to be prepared in a shorter time. Moreover, normally notice of proposed rulemaking and opportunity to comment is required to be published before such amendments can become effective. The procedures about which you complain actually shorten the time that would otherwise be necessary for these changes to take effect. The form letter which you refer to as providing approval is

no more than an acknowledgment and indicates only that the tire size designations and rim sizes in question will be included in the next amendment to the Appendices, under the special procedures which allow their use in 30 days if objections are not received.

For these reasons, we have not found it administratively practicable to publish notices of additional tire sizes whenever they may be received. We have indicated our intention to publish amendments quarterly. While we have not met this schedule as consistently as we hoped, we expect to improve our efforts in this regard in the future.

ID: 23871.jeg

Mr. Philip M. Headley
Chief Engineer, Advanced Technologies
Continental Teves
4141 Continental Drive
Auburn Hills, MI 48326

Dear Mr. Headley:

This responds to your request for an interpretation of Federal Motor Vehicle Safety Standard No. 135. You stated that Continental Teves has developed a system which uses the ABS hydraulic pump to supplement the driver's braking effort in the event of a vacuum booster failure. The system is able to recognize the booster failure and meter hydraulic fluid from the ABS pump to the wheel brakes in response to the driver's pedal force. You are concerned, however, that the driver may not recognize that the vacuum boost failure has occurred, since the brakes may appear to operate normally. Consequently, the driver may not have the vacuum booster problem repaired. A subsequent malfunction of the ABS system could then render the vehicle unable to meet the failed boost requirements of Standard No. 135.

You stated that you believe the prudent action in this case would be to light the brake telltale to alert the driver of the problem. You asked whether this would be permissible under Standard No. 135, given that booster failure is not one of the specified conditions for which the brake telltale is required to be illuminated. As discussed below, the answer to your question is yes.

By way of background, the National Highway Traffic Safety Administration (NHTSA) does not provide approvals of motor vehicles or motor vehicle equipment. Under 49 U.S.C. Chapter 301, manufacturers are required to ensure that their vehicles and equipment meet applicable requirements. The following represents our opinion based on the facts you provided in your letter.

As you noted in your letter, we have previously addressed a similar question from General Motors (GM) in the context of the requirements of Standard No. 105. (Letter to Stephen E. Selander, Esq., dated April 29, 1992.) S5.3.1 of that standard required a brake telltale to illuminate when there was a gross loss of hydraulic pressure (or, alternatively, a drop in fluid level), a total functional electrical failure in the antilock or variable proportioning brake system, and when the parking brake was applied. GM stated that a brake telltale on a planned vehicle would illuminate under these prescribed conditions. That company indicated, however, that a diagnostic capability would also exist to detect other faults in the brake system, and requested the agency's concurrence that S5.3.1 permitted illumination of the brake telltale when other faults were detected which increased the likelihood of a substantial degradation in brake system performance.

We noted that while Standard No. 105 required that a brake telltale be provided which activated under certain specified conditions, it did not expressly state whether the required telltale may also be activated under other conditions. We provided our opinion that the telltale may also activate under other conditions so long as such activation does not obscure or confuse the meaning of the required telltale or otherwise defeat its purpose.

We noted that the purpose of the brake telltale was to warn the driver of one of two conditions: (1) the parking brake was applied (and hence should be released before driving), or (2) the brake system had a significant fault which should be corrected. Since the additional conditions for activation which GM contemplated would represent significant brake system faults which should be corrected, it was our opinion that activation of the brake telltale under such conditions would not in any way defeat the purpose of the brake telltale.

We believe the rationale of our interpretation to GM is directly applicable to the question you ask about the very similar brake telltale requirements of Standard No. 135.

S5.5 of Standard No. 135 requires one or more brake telltales to be provided which activate under two types of specified conditions: (1) the parking brake is applied, and (2) the brake system has a significant fault which should be corrected. Since the additional condition for which Continental Teves contemplates activation of the brake telltale also represents a significant fault in the brake system which should be corrected, it is our opinion that activation under that condition would not in any way defeat the purpose of the brake telltale, and is permissible under Standard No. 135.

I hope this information is helpful. If you have any further questions, please call Edward Glancy of my staff at (202) 366-2992.

Sincerely,

Jacqueline Glassman
Chief Counsel
ref:135
d.5/30/02

ID: nht90-4.28

TYPE: Interpretation-NHTSA

DATE: October 1, 1990

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: Stephen R. Darling -- Presvac Systems (Burlington) Ltd.

TITLE: None

ATTACHMT: Attached to Federal Register, 49 CFR Part 575, (11-27-89 Edition), pages 48745-48749 (text omitted); Also attached to letter dated 5-11-90 from S.R. Darling to NHTSA (OCC 4805); Also attached to letter dated 5-31-90 from S.P. Wood to S. Nishibo ri (Part 575.6)

TEXT:

This responds to your inquiry about an amendment to 49 CFR Part 575, Consumer Information Regulations, requiring vehicle manufacturers to include information in the owner's manual (or on a one-page document if there is no owner's manual) about the Nation al Highway Traffic Safety Administration's Auto Safety Hotline and its defect investigation and remedy and recall authority. (54 FR 48745, November 27, 1989; copy enclosed). I apologize for the delay in our response.

You explained that you are involved in three types of activities: the manufacture of liquid cargo vessel trailers; the fabrication of liquid cargo tanks; and the installation of these tanks onto existing or modified truck chassis. While you acknowledged your obligation to furnish the consumer information for the trailers you manufacture, you were uncertain about your responsibilities to furnish this information for the liquid cargo tanks you fabricate and install. You asked whether you are required to supply the specified consumer information in these instances. Your questions are responded to below.

Section 575.6(a)(2)(i), as amended, provides that "At the time a motor vehicle manufactured on or after September 1, 1990 is delivered to the first purchaser for purposes other than resale, the manufacturer shall provide to the purchasers a specified sta tement about this agency's activities related to motor vehicle defects. Among other things, the specified statement indicates that if an owner believes the vehicle has a defect which could cause a crash or an injury or death, the owner should inform NHT SA in addition to notifying the manufacturer. The manufacturer's name must be indicated in the statement.

In responding to your questions, I note that section 575.6(a)(2)(i) applies to manufacturers of new motor vehicles. As a manufacturer of trailers, you are, of course, responsible for providing the specified consumer information to the first purchaser of such trailers (for purposes other than resale). On the other hand, in situations where you are not a vehicle manufacturer, e.g., where you may be installing tanks on used motor vehicles, the requirements would not apply.

Your letter also raises the issue of how section 575.6(a)(2)(i) applies in situations where there is more than one manufacturer of a motor vehicle, i.e., where vehicles are manufactured in two or more stages. While it is not clear from your letter, it i s possible that you may be a final stage manufacturer under 49 CFR Part 568. (The term "final stage manufacturer"

is defined in 49 CFR Part 568.3.)

As indicated above, section 575.6(a)(2)(i) specifies that, at the time a vehicle is delivered to the first purchaser for purposes other than resale, "the manufacturer" must provide specified consumer information to the purchaser. Since the regulation re quires information to be provided at the time of first consumer sale, we construe it to require the manufacturer of the completed vehicle, i.e., the final stage manufacturer, to meet this requirement. As a general rule, the final stage manufacturer is t he manufacturer that has the closest relationship to the dealer which sells the vehicle to the consumer. It is also the manufacturer that the consumer will typically contact first in the event of problems.

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

ID: 2677y

Mr. Stephen R. Darling
Presvac Systems (Burlington) Ltd.
4131 Morris Drive
Burlington, Ontario, Canada L7L 5L5

Dear Mr. Darling:

This responds to your inquiry about an amendment to 49 CFR Part 575, Consumer Information Regulations, requiring vehicle manufacturers to include information in the owner's manual (or on a one-page document if there is no owner's manual) about the National Highway Traffic Safety Administration's Auto Safety Hotline and its defect investigation and remedy and recall authority. (54 FR 48745, November 27, 1989; copy enclosed). I apologize for the delay in our response.

You explained that you are involved in three types of activities: the manufacture of liquid cargo vessel trailers; the fabrication of liquid cargo tanks; and the installation of these tanks onto existing or modified truck chassis. While you acknowledged your obligation to furnish the consumer information for the trailers you manufacture, you were uncertain about your responsibilities to furnish this information for the liquid cargo tanks you fabricate and install. You asked whether you are required to supply the specified consumer information in these instances. Your questions are responded to below.

Section 575.6(a)(2)(i), as amended, provides that "At the time a motor vehicle manufactured on or after September 1, 1990 is delivered to the first purchaser for purposes other than resale, the manufacturer shall provide to the purchaser" a specified statement about this agency's activities related to motor vehicle defects. Among other things, the specified statement indicates that if an owner believes the vehicle has a defect which could cause a crash or an injury or death, the owner should inform NHTSA in addition to notifying the manufacturer. The manufacturer's name must be indicated in the statement.

In responding to your questions, I note that section 575.6(a)(2)(i) applies to manufacturers of new motor vehicles. As a manufacturer of trailers, you are, of course, responsible for providing the specified consumer information to the first purchaser of such trailers (for purposes other than resale). On the other hand, in situations where you are not a vehicle manufacturer, e.g., where you may be installing tanks on used motor vehicles, the requirements would not apply.

Your letter also raises the issue of how section 575.6(a)(2)(i) applies in situations where there is more than one manufacturer of a motor vehicle, i.e., where vehicles are manufactured in two or more stages. While it is not clear from your letter, it is possible that you may be a final stage manufacturer under 49 CFR Part 568. (The term "final stage manufacturer" is defined in 49 CFR Part 568.3.)

As indicated above, section 575.6(a)(2)(i) specifies that, at the time a vehicle is delivered to the first purchaser for purposes other than resale, "the manufacturer" must provide specified consumer information to the purchaser. Since the regulation requires information to be provided at the time of first consumer sale, we construe it to require the manufacturer of the completed vehicle, i.e., the final stage manufacturer, to meet this requirement. As a general rule, the final stage manufacturer is the manufacturer that has the closest relationship to the dealer which sells the vehicle to the consumer. It is also the manufacturer that the consumer will typically contact first in the event of problems.

I hope this information is helpful. If you have any further questions, 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 Enclosures ref:568#575 d:l0/l/90

ID: 20551.drn

Father Joseph Rinaldo, S.C.
Administrator
St. Louis Center
16195 Old U.S. 12
Chelsea, MI 48118-9646

Dear Father Rinaldo:

This responds to your request for an interpretation of whether your institution for developmentally disabled children must use school buses to transport the children. Your letter states that the Saint Louis Center provides "only therapeutic and social services" for the children and that your "residents are bused to the public school" by the local school district in school buses. Because we regulate the manufacture and sale of new school buses and not their use, whether you must use school buses is determined by Michigan State law. As to whether you must be sold a school bus when you purchase a new bus, we believe the answer to that question is no.

Some background information may be helpful. The National Highway Traffic Safety Administration ( NHTSA) is authorized to issue and enforce Federal motor vehicle safety standards (FMVSS) applicable to new motor vehicles. Our 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 standards. Accordingly, persons selling or leasing a new "school bus" must sell or lease a vehicle that meets the safety standards applicable to school buses.

Our statute defines a "schoolbus" as any vehicle that is designed for carrying a driver and more than 10 passengers and which, NHTSA decides, is likely to be "used significantly" to transport "preprimary, primary, and secondary" students to or from school or related events. 49 U.S.C. 30125. By regulation, the capacity threshold for school buses corresponds to that of buses -- vehicles designed for carrying more than ten (10) persons. For example, a 15-person van that is likely to be used significantly to transport students is a "school bus."

Because our laws apply only to the manufacture and sale of new motor vehicles, we do not prohibit institutions like the St. Louis Center that care for children from using their large vans to transport school children even when the vehicles do not meet Federal school bus safety standards. However, each State has the authority to set its own standards regarding the use of motor vehicles, including school buses, so you should also check Michigan law to see if there are regulations about how you must transport your children.

As to whether a "school bus" must be sold to a facility when the facility wishes to purchase a new bus, the answer depends partly on whether the facility provides educational programs (and thus is a "school") or is strictly custodial (and thus is not considered by us to be a school). However, in recent interpretations (see the attached July 23, 1998 letter to Mr. Don Cote) we have stressed that the answer also depends on the purpose for which the bus is used. If a custodial center were purchasing a new bus to use significantly to transport students to or from a school or school-related events, a dealer knowing of this purpose is required to sell a school bus. In the situation you present, it does not appear that the St. Louis Center is providing "significant" transportation for the children to or from school or for school-related events. Thus, we believe that a dealer is not obligated to sell you a school bus.

In fully addressing the type of vehicle that should be used to transport your children, I ask that you take the following into consideration. At a June 8, 1999, public meeting, the National Transportation Safety Board (NTSB) issued the attached abstract of a special investigative report on nonconforming buses. The NTSB issued the report after investigating in 1998 and 1999, four crashes in which 9 people were killed and 36 injured when riding in "nonconforming buses." NTSB defines "nonconforming bus" as a "bus that does not meet the FMVSSs specific to school buses." Most of the victims, including eight of the fatalities, were children.

In the abstract of its report, the NTSB issued several Safety Recommendations, including the following that was directed to child care providers such as the National Association of Child Care Professionals, the National Child Care Association, and Young Mens' and Young Women's Christian Associations:

Inform your members about the circumstances of the accidents discussed in this special investigation report and urge that they use school buses or buses having equivalent occupant protection to school buses to transport children.

In conclusion, 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 to transport school children be certified as meeting NHTSA's school bus safety standards. In addition, using 15-person vans that do not meet NHTSA's school bus standards to transport students could result in liability in the event of a crash.

I hope this information is helpful. For more information about the safety features of a school bus, I am enclosing NHTSA's publication: "School Bus Safety: Safe Passage for America's Children." I am also enclosing NHTSA's February 1999 "Guideline for the Safe Transportation of Pre-school Age Children in School Buses."

If you have any further questions about NHTSA's programs please feel free to contact Dorothy Nakama at this address or at (202) 366-2992. Information about NTSB's nonconforming bus report is available from the NTSB's Public Affairs Office at (202) 314-6100.

Sincerely,
Frank Seales, Jr.
Chief Counsel
Enclosures
ref:VSA#571.3
d.9/29/99

ID: 8-29-02Johnsonltr

Mr. Frank Johnson
Executive Vice President
Nichirin Inc.
139 Copernicus Boulevard
Brantford, Ontario
CANADA N3P 1N4




Dear Mr. Johnson:

This responds to your letter, which we received on June 3, 2002, regarding Federal Motor Vehicle Safety Standard ("FMVSS") No. 106, Brake Hoses. Specifically, you ask whether stainless steel braided brake hoses must meet the striping requirements of S5.2.1, Labeling. The answer is yes, unless the hoses are either sold as part of a motor vehicle or manufactured for use only in an assembly whose end fittings prevent the hoses from being installed in a twisted orientation.

S5.2.1 requires that "[e]ach hydraulic brake hose, except hose sold as part of a motor vehicle, shall have at least two clearly identifiable stripes of at least one-sixteenth of an inch in width, placed on opposite sides of the brake hose parallel to its longitudinal axis." 49 CFR 571.106. In addition, S5.2.1 provides that "hydraulic brake hose manufactured only for use in an assembly whose end fittings prevent its installation in a twisted orientation in either side of the vehicle, need not" meet the striping requirement. 49 CFR 571.106.

You indicate in your letter that Honda is proposing to use stainless steel braided hoses in a "new vehicle program" and you ask whether the outer mesh of these hoses needs to be striped. As indicated above, the requirements of S5.2.1 apply to all hydraulic brake hoses, not only those made of rubber. S5.2.1 does not exclude stainless steel braided brake hoses from the striping requirement. (See also May 12, 1994 letter to Mr. Jim Davis, Russell Performance Products, copy enclosed.) Accordingly, the stainless steel braided hose about which you inquire must be striped unless they meet either of S5.2.1's two exceptions.

If you supply brake hoses to Honda and the hoses are only installed on newly-manufacured vehicles, then the hoses would not need to be striped under S5.2.1. However, if Honda were to sell any of the brake hoses as replacement parts, and therefore they are not installed on a new motor vehicle, then they would need to be striped unless they are constructed in such a way or have unique features that would prevent their being installed in a twisted manner when they are put on the vehicle as replacement brake hoses.

Finally, we note that the agency has been petitioned by Parker Hannifin to update FMVSS No. 106. NHTSA granted the petition and is now evaluating the issues raised therein. If you are interested in reviewing a copy of this petition, you may access it at the following web address:
http://dms.dot.gov/search/document.cfm?documentid=46189&docketid=4367

I hope this information is helpful. If you have any questions, you may contact Robert Knop of this office at (202) 366-2992.

Sincerely,

Jaqueline Glassman
Chief Counsel

Enclosure
ref:106
d.9/6/02

ID: 11613WKM

Mr. Harold J. Herzlich
Herzlich Consulting, Inc.
8908 Desert Mound Drive
Las Vegas, NV 89134

Dear Mr. Herzlich:

This responds to your letter dated February 5, 1996 in which you asked this agency to reverse its denial of your petition of June 13, 1995. You had suggested in your petition that the National Highway Traffic Safety Administration (NHTSA) should amend the tire standards to require the Awearout indicators,@ currently required on tires, to be 3/32 inch, rather than the current requirement of 2/32 inch.

You state in your letter that NHTSA incorrectly paraphrased some of the justifications you provided in your petition to support the suggested amendments. You also state your belief that NHTSA=s denial of your petition was based on possibly obsolete 1967-1975 data, and that a public hearing is therefore necessary to develop the data pertinent to your proposal. Finally, you asked that your petition letter "be attached to any notice of action so the record will show the exact context of [your] comments."

The agency thoroughly evaluated your petition and discussed our rationale for denying it in the document published in the Federal Register on January 30, 1996 (denial of petition for rulemaking, 61 FR 2991). We continue to believe that our understanding and summary of the statements in your petition were accurate and that our stated rationale for the denial of your petition was based on relevant data. You provided no new information or data in your letter to supplement the assertions in your petition. Accordingly, the agency does not see reason to revisit the issues raised in your petition.

As you requested, a copy of your petition of June 13, 1995 will be attached to copies of your letter and of this response, for inclusion in the agency's public docket.

Thank you for your interest in motor vehicle safety.

Sincerely,

Samuel J. Dubbin Chief Counsel

ref:109 d:4/16/96

ID: nht79-2.18

DATE: 12/05/79

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Mack Trucks, Inc.

TITLE: FMVSS INTERPRETATION

TEXT:

Mr. Thomas F. Brown Mack Trucks, Inc. P.O. Box 1761 Allentown, Pennsylvania 18105

Dear Mr. Brown:

This responds to your recent letter regarding Safety Standard No. 106-74, Brake Hoses, and several discrepancies between the standard as published in the Federal Register and as published in the "Federal Motor Vehicle Safety Standards and Regulations" compilation.

You are correct in your assumption that the Federal Register version of the subject paragraphs is the proper publication. The temperature noted in paragraph S5.3.10 should read, "104oF". The heading, "S7.2 Labeling", should be included. In paragraph S7.3.6, the parenthetical phrase is out of place as you indicated, and the additional words are unnecessary editorial citations. The proper address for paragraph S5.2.2(b) should read: "Office of Vehicle Safety Standards, Crash Avoidance Division,...."

Thank you for bringing these errors to our attention. They will be corrected in future versions of the compilation.

Sincerely,

Frank Berndt Chief Counsel

October 31, 1979

Mr. F. Berndt, Chief Counsel National Highway Traffic Safety Administration U.S. Department of Transportation 400 Seventh Street, S.W. Washington, D.C. 20590 Dear Mr. Berndt:

Subject: Discrepancies in Standard No.

106 74, Brake Hose, as published in the Federal Motor Vehicle Safety Standards and Regulations

Upon recent review of Standard No. 106-79, Brake Hose, we have found several discrepancies between the Standard as published in the Federal Register and as published in the Federal Motor Vehicle Safety Standards and Regulations compilation.

It appears that the temperature noted in Section S5.3.10 of he compilation is incorrectly printed as "140oF" instead of "104oF".

The heading "S7.2 Labeling" has been omitted from page 7 of the compilation.

Section S7.3.6 has a phrase out of place and a few extra words.

Finally, all Sections of the Standard listing an address to which information is to be sent, except for Section S5.2.2(b), show the address as "Office of Vehicle Safety Standards, Crash Avoidance Division,...." Section S5.2.2(b) shows the address as "Office of Crash Avoidance, Handling and Stability Division,...."

Both the compilation and the Federal Register agree on the previous two addresses. We are wondering if the address in Section S5.2.2(b) was inadvertently overlooked. Should all the addresses be the same?

We trust that you will have these areas reviewed and advise us of your findings. We have attached the appropriate pages from the compilation for your reference.

Very truly yours,

MACK TRUCKS, INC. Thomas F. Brown Executive Engineer- Vehicle Regulations and Standards

vy

Attach.

ID: 13967.wkm

Mr. Fred J. Turcotte
2633 Parisian Court
Punta Gorda, FL 33950-6325

Dear Mr. Turcotte:

Please pardon the delay in responding to your letter to this agency recommending that auto manufacturers provide interior latches in trunk lids so that a person could escape if locked inside.

You stated in your letter that many car hijackings, commonly called carjackings, are taking place and that in many instances, the perpetrator locks the victim in the trunk, then takes the victim to a remote place and murders him or her. You stated that an interior latch could provide the victim a means to escape.

An interior latch may or may not be effective as a means of escaping from the trunk. The agency is concerned that criminals such as carjackers, knowing that there is an interior latch in the trunk, could disable the latch, or worse, incapacitate the victim before placing him or her in the trunk. In addition, we have no data on the number of deaths or injuries attributable to intentional or inadvertent entrapment in the trunk of a car. Accordingly, we have no basis at this time to issue regulations requiring latches on the insides of trunk lids.

We will, however, continue to monitor our defect complaint files, and law enforcement data to be alert to potential problems of this nature. These are measures we normally take in our continuing efforts to improve motor vehicle safety.

I hope this information is helpful to you, and thank you for your interest in motor vehicle safety.

Sincerely,
John Womack
Acting Chief Counsel
ref:5/30/97
d:5/30/97

ID: nht74-3.36

DATE: 05/06/74

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Heavy & Specialized Carriers Conference of American Trucking Associations

TITLE: FMVSR INTERPRETATION

TEXT: This responds to your April 23, 1974, request for an explanation of the meaning and use of the term "Gross axle weight rating" (GAWR) in Federal motor vehicle safety standards.

The concept of GAWR and "Gross vehicle weight rating" (GVWR) are interrelated, and the two terms are defined as follows:

"Gross axle weight rating" or "GAWR" means the value specified by the manufacturer as the load-carrying capacity of a single axle system, as measured at the tire-ground interfaces.

"Gross vehicle weight rating" or "GVWR" means the value specified by the manufacturer as the loaded weight of a single vehicle.

In both cases it is the manufacturer who specifies the values, and he is free to specify whatever values he himself decides are correct. Both the NHTSA in its compliance tests, and the Bureau of Motor Carrier Safety on the road, will judge the vehicle on the basis of the values assigned. Therefore it is in the interest of the manufacturer to assign values which accurately reflect the load-bearing ability of the vehicle and its suspension.

The sum of the GAWR's must at least equal the specified GVWR to avoid overloading the axle systems, and the GAWR sum may, of course, exceed the GVWR. Typically the manufacturer balances the commercial advantage of specifying a higher GVWR against the expense of higher GAWR's.

The GAWR is measured at the tire-ground interfaces which means that the tires, wheels, brakes and suspension components are included in the determination. Typically an axle assembly is rated by its manufacturer, who takes into account the braking ability of the axle to stop the load. Although this factor should always have been taken into consideration, the advent of Standard 121 may cause axle and brake manufacturers to reassess the values they have assigned to brake systems in the past.

YOURS TRULY,

Heavy & Specialized Carriers Conference Of American Trucking Associations

April 23, 1974

Thomas Herlihy Office of the Chief Counsel National Highway Traffic Safety Administration

Please accept our sincere thanks for the meeting held at your offices on April 9, 1974 in which we discussed the impact of MVSS No. 121 on the heavy and specialized carrier industry. To further "introduce" you and your staff to our industry, I am enclosing a copy of our current Membership Directory and a recent issue of our monthly magazine TRANSPORTATION ENGINEER.

At the meeting we discussed briefly the intended meaning of the "24,000 pound gross axle weight rating" appearing in your proposed amendment in the March 1, 1974 FEDERAL REGISTER and you indicated that the intent was to use the current axle rating system as opposed to the MVSS No. 121 axle rating system in which braking ability would play a major limiting role. As a quick review of the enclosed magazine will reveal, this technical factor is of the utmost importance to our members who are the nation's primary users of this type of equipment.

We would appreciate a reply indicating the correct usage and application of this "24,000 pound gross axle weight rating" as it appears in that FEDERAL REGISTER item. If there are any questions concerning this inquiry, please feel free to call on us.

And again, please accept our sincere appreciation for the meeting last week.

Douglas A. Hughes

Director of Transportation

Enclosures