ID: 17343-2.pja

Mr. Robert S. Toms
Manager of Engineering
Power Brace
7640 60^th Ave.
Kenosha, WI 53142

Dear Mr. Toms:

This responds to your letter requesting an interpretation of whether the elastomeric material your company manufactures could be used to comply with the energy absorption requirements of the National Highway Traffic Safety Administration's (NHTSA's) rear impact protection (underride guard) regulations. Specifically, you ask whether the requirement that the energy absorption be accomplished by plastic deformation would preclude a material that returns to its original shape (i.e., elastic) very slowly, on the order of approximately 24 hours. As explained below, this material could be used as the active energy absorbing material to pass our compliance tests.

Federal Motor Vehicle Safety Standard No. 223, Rear impact guards (49 CFR 571.223, published on January 24, 1996 at 61 FR 2004) requires that underride guards fitted to new trailers and semitrailers provide a certain amount of energy absorption to lessen the crash forces on a passenger vehicle colliding from the rear. S5.2.2 of the standard states that "[a] guard  . . .shall absorb by plastic deformation within the first 125 mm of deflection at least 5,650 J of energy at each test location P3" (emphasis added). The test procedures basically require application of a force by a steel block, while recording the force at least ten times per 25 mm, until the guard has been deflected 125 mm. S6.6(c) then requires NHTSA to "[r]educe the force until the guard no longer offers resistance to the force application device. Produce a force vs. deflection diagram . . . Determine the energy absorbed by calculating the . . . area bounded by the curve of the force vs. deflection diagram and the abscissa (x-axis)" (emphasis added). Therefore, the elastic component of energy is not normally counted toward meeting the energy absorption requirements.⁽¹⁾

One word in S5.2.2 that requires interpretation in this case is the word "plastic." In this context, plastic means capable of being molded, bent, or assuming a new form or shape. Although plastic deformation is normally thought of as permanent, and elastic deformation temporary, there is no time frame explicitly attached to these meanings. Whenever appropriate, NHTSA interprets its regulations consistent with their purposes.⁽²⁾ The requirement that guards absorb energy was designed to ensure that guards were not too rigid during the onset of force in a crash. The requirement that they absorb the energy by plastic deformation was to ensure that the guard did not subsequently return the absorbed energy to the colliding vehicle, because that energy return could increase the chance of death or injury to the occupants. However, any rebound occurring after the crash event, especially slow rebound such as is produced by your elastomer, does not pose any threat to passenger vehicle occupants. Therefore, for real world safety purposes, the time frame within which a material must retain its deformed shape to be considered "plastic" is the duration of a crash event.

The relevant time period for compliance purposes, however, is longer. Standard No. 223 employs a quasi-static test, not a dynamic test, when it tests for compliance with its requirements. NHTSA has no way of determining whether a material would rebound within the time frame of the crash. Therefore, if your elastomer reacts in such a way that it passes the test procedure, it will have passed the requirements, for practical purposes. The critical piece of information you need to determine whether your material will pass the test is when the test ends.

A specific event determines when the test ends. The force application/withdrawal portion of the test procedure is over as soon as the guard no longer offers resistance to the force application device. Since S6.6(c) is a list of steps to be performed, it is reasonable to assume that once a certain step is completed, the next step will be commenced. The step of reducing the force proceeds only "until the guard no longer offers resistance." In practical terms, the guard will generally cease to offer resistance when it loses contact with the force application device. NHTSA has no way of determining any small amount of residual force generated by your elastomer after that point. A properly calibrated load cell (a typical load measuring device) should register zero load, and the force deflection trace should meet the abscissa of the graph upon separation. After that happens, the test itself is completed and all that remains is the computation of the amount of energy absorbed using the area within the force deflection curve.

For a manufacturer to predict the energy absorption of a guard equipped with your elastomer during NHTSA's compliance testing, it needs to have some idea of the rate at which the force application device will be withdrawn. Although the event concluding the test is known, that event can occur at different times, resulting in different amounts of measured energy absorption from the same guard. For example, if the force application device is withdrawn slowly enough, your company's slow-rebounding elastomer may never lose contact with the guard, which could result in a computation showing little apparent energy absorption. On the other hand, if it is withdrawn quickly from the same guard, the force application device would lose contact quickly and more apparent energy would be absorbed.

The rate of withdrawal has not been specified in the regulation or in the test procedures. The equipment that NHTSA and most manufacturers use to test the guards determines, to a large extent, the rate of withdrawal. Force is normally applied using a large hydraulic ram, powered by pumps. Using this system, the ram is withdrawn by reversing the pump. This results in a withdrawal rate about the same as the rate of force application. This relief of force also enhances the safety of the persons performing the test and lengthens the life of the test equipment by reducing the chances of a catastrophic failure of some part of the test device.

Specifying a particular rate of force withdrawal is not necessary or practical. To provide flexibility to the manufacturers, S6.6(a) of the test procedure permits the manufacturer to specify the rate of force application, within a range of 2.0 to 9.0 cm per minute. To accommodate the manufacturer's specified force application rate and guard design, NHTSA may have to vary its test equipment, which might affect the rate at which it can withdraw the force application device. However, it is reasonable to assume that NHTSA can withdraw the force application device at least as quickly as it applied the force.

Therefore, where possible, NHTSA will withdraw the force application device at a rate equal to or slightly faster than the manufacturer's specified force application rate. This gives the manufacturers some control by allowing them to specify the lower bound for the withdrawal rate. If the manufacturer tested its guard by withdrawing the guard at the force application rate, or a little slower, then the amount by which the NHTSA's rate of withdrawal might be higher than the specified rate is not critical, because higher withdrawal rates can only result in earlier separation of the guard from the force application device, and a higher level of computed energy absorption by the guard. In other words, the higher the rate, the more likely the guard is to comply with the energy absorption requirement.

In summary, your elastomer could be used to comply with the standard if it passes the compliance test in Standard No. 223. Based on your description of the behavior of the elastomer, we see no reason why a guard equipped with it would not be able to pass our compliance tests. If you have any further questions, please feel free to contact Paul Atelsek of my staff at this address or by telephone at (202) 366-2992.

Sincerely,
Frank Seales, Jr.
Chief Counsel
ref:224
d.8/4/98

1. These requirements, as stated, are adequate for testing guards made of most materials. Most guards made of steel would exhibit only a small amount of elastic deformation. Therefore, the guard would stay deformed and the force curve would descend to and intersect the abscissa close to the maximum deformation, exhibiting little rebound. Most elastic materials would rebound quickly and completely, following closely the curve produced during force application, descending to the abscissa only at the point of origination. However, your elastomer returns the energy very slowly.

2. When a standard does not specify a particular test condition, we begin with a presumption that the requirements must be met in every test condition in which the test can be conducted. See, for example, NHTSA's October 2, 1990 letter to Mr. S. Kadoya of Mazda. In this case, that would mean that the agency could retract the test device at any rate. However, the agency also looks to the language and purposes of the standard to see if a limitation should be implied. In this case, we find an implied limitation on the retraction speed based on the standard's purposes. Retracting the device at extremely low rates would also only prolong testing.

ID: aiam3478

Dear Mr. DiMaio: This is in response to your telephone inquiry of October 13, 1981 asking whether tire tread labels required under the Uniform Tire Quality Grading (UTQG) Standards must continue to be affixed to tires once applicable UTQG grades are added to sidewall molds for the tires. The UTQG regulation contemplates that tire grading information will be made available to consumers simultaneously through a variety of means, including tread labels (49 CFR S 575.104(d)(1)(i)(B)), sidewall molding (49 CFR S 575.104(d)(1)(i)(A)), and leaflets available at the point of sale (49 CFR S 575.104(d)(1)(ii)). While the regulation was recently amended to permit tire grades to be molded on the tire sidewall at any time up to six months after introduction of a new tire line (46 FR 41514, August 17, 1981), this change in no way affected the obligation imposed by S 575.104(d)(1)(i)(B) that UTQG tread labels be affixed to all replacement tires to which the regulation applies. Thus, once the sidewall molding requirement takes effect for a line of tires, the regulation requires that UTQG information be displayed on the tires both by means of sidewall molding and by labels attached to the tread surface.; Sincerely, Frank Berndt, Chief Counsel

ID: aiam3479

Dear Mr. DiMaio: This is in response to your telephone inquiry of October 13, 1981 asking whether tire tread labels required under the Uniform Tire Quality Grading (UTQG) Standards must continue to be affixed to tires once applicable UTQG grades are added to sidewall molds for the tires. The UTQG regulation contemplates that tire grading information will be made available to consumers simultaneously through a variety of means, including tread labels (49 CFR S 575.104(d)(1)(i)(B)), sidewall molding (49 CFR S 575.104(d)(1)(i)(A)), and leaflets available at the point of sale (49 CFR S 575.104(d)(1)(ii)). While the regulation was recently amended to permit tire grades to be molded on the tire sidewall at any time up to six months after introduction of a new tire line (46 FR 41514, August 17, 1981), this change in no way affected the obligation imposed by S 575.104(d)(1)(i)(B) that UTQG tread labels be affixed to all replacement tires to which the regulation applies. Thus, once the sidewall molding requirement takes effect for a line of tires, the regulation requires that UTQG information be displayed on the tires both by means of sidewall molding and by labels attached to the tread surface.; Sincerely, Frank Berndt, Chief Counsel

ID: nht69-2.46

DATE: 09/25/69

FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA

TO: Toyota Motor Company Ltd.

TITLE: FMVSR INTERPRETATION

TEXT: This is to confirm the information given to you by Mr. Richard Dyson of this office by telephone on September 19, 1969, concerning the consumer information regulations, in response to your telegram of September 15.

Your understanding of section 375.106, Acceleration and Passing is correct. The acceleration interval may be begun in any gear, and the gears may be shifted during the interval.

You also asked how long "manufacturers are responsible after the sale of a vehicle for the information they provide." The regulations apply to manufacturers, so that strictly speaking the information is only required to be correct for vehicles at the point of sale to a person for purposes other than resale -- as is the case with the Standards. In other words, there is no implied requirement in regard to vehicle degradation with use. If a vehicle in use were found not to perform in accordance with the consumer information, however, (or not to conform to standards) that fact might be strong evidence of a violation by the manufacturer in the design or production of the vehicle.

You should also note that the consumer information regulations relating to braking and acceleration performance specify that a period of burnishing or breaking in shall be completed before the performance is measured.[Illegible Page)[Illegible Page)

ID: nht92-9.16

DATE: February 10, 1992

FROM: Brad Beach

TO: Taylor Vinson -- U.S. Department of Transportation

TITLE: None

ATTACHMT: Attached to letter dated 4/14/92 from Paul Jackson Rice to Brad Beach (A39; Std. 205)

TEXT:

I am writing you to obtain information and literature on the laws and restrictions of attaching objects to the rear and side windows of the automobile.

I am interested in putting an object that is rectangle in shape with dimensions of 18 inches in length and 12 inches in width and it is not transparent. It could definitely hinder the drivers vision depending where it was placed. But my question is at what point does it become illegal to have the object placed on the window? Is it only in certain places that I could be written a citation or is it illegal to have it placed anywhere on the rear window? side window?

I spoke with Kevin Cavey from your department and he suggested to write you in order to obtain literature that would state the laws and answer my questions concerning the automobile windows.

Mr. Vinson, thank you for your time. Please send information to the address below.

ID: nht81-3.31

DATE: 11/02/81

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Department of Transportation - New York

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your September 8, 1981 letter enclosing correspondence from Mrs. Barbara Stephens asking about extending the seat spacing in a school bus that is designed to transport handicapped children. You ask for general guidance in this area.

First, let me say that the safety standards apply to manufacturers of vehicles as well as those individuals that alter new motor vehicles. Further, repair businesses are not permitted to render inoperative the compliance of a vehicle with the safety standards. On the other hand, nothing prohibits an individual from rendering inoperative the compliance of his or her own vehicle with any safety standard.

In specific reference to seat spacing in school buses, two general rules apply. First, seat spacing is not regulated in vehicles with gross vehicle weight ratings (GVWR) of 10,000 pounds or less. Accordingly, any modification of seat spacing in these vehicles is permissible. Second, in vehicles with GVWR's in excess of 10,000 pounds, seat spacing is regulated, and a manufacturer may not produce a vehicle whose spacing exceeds the specifications set in Standard No. 222, School Bus Passenger Seating and Crash Protection. Further, a repair business may not affect the seat spacing in a way that would violate the standard. An owner, however, may change the spacing in his or her own vehicle.

The agency has specifically provided for the transportation of the handicapped by allowing the installation of side-facing seats in school vehicles designated for handicapped transportation. We would suggest that this is a more suitable approach than extending seat spacing. By extending seat spacing, a school would be taking its vehicles out of compliance with the safety standards. In the event of an accident involving one of these vehicles, the school might be subject to unnecessary liability for having made these modifications to its vehicles.

I hope that this will be of use to you in advising schools of the Federal requirements, and if I can be of further assistance, please contact me.

SINCERELY,

NEW YORK STATE

DEPARTMENT OF TRANSPORTATION

September 8, 1981

Roger Tilton Office of Chief Counsel N.H.T.S.A.

Dear Mr. Tilton:

We recently received the attached request and contacted a member of your organization (Mr. Robert Williams) to determine the application of Federal Motor Vehicle Safety Standards once a vehicle reaches the users hands.

Since Medical Motor Service intended to modify the vehicle after taking title, it was determined that the standards did not apply since they are designed for manufacturers and manufacturers' representatives.

In discussing this situation, it was decided that we should send you a copy of the request since your organization is in the process of analyzing needs for handicapped transportation. We would appreciate your reactions and thoughts concerning the proposed modification. It is quite possible that similar circumstances might arise in the future and since we have no substantive guidelines to follow, your research in this general area might provide us with some input that will enable us to better cope with these situations.

We have already advised the company officials that there are no restrictions that would deny them the right to modify their vehicle so we are not delaying this operation in anyway while your review process takes place. Thank you for any help you can provide in this area.

JOHN H. SHAFER, Director Traffic and Safety Division

BY

MARTEN V. CHAUVIN, Chief Carrier Safety Bureau

ATTACH.

CC: BARBARA M. STEPHENS, EXECUTIVE DIR, MEDICAL MOTOR SERVICES; G. HUSSONG, TRAFFIC & SAFETY, REGION

ID: aiam4536

"Dear Mr. Smith: This responds to your letter concerning th application of Federal safety standards to your manufacture of a 'storage console-armrest.' I regret the delay in responding. The illustration you included in your letter shows that the console apparatus is designed to be placed on a bench seat and is not attached in any manner to the seat structure. The console-armrest has a wood frame, is entirely covered with fabric, and has a hinged, padded top which can be flipped open for access to the storage area. By way of background information, the National Highway Traffic Safety Administration (NHTSA) is authorized by the National Traffic and Motor Vehicle Safety Act to issue Federal motor vehicle safety standards that set performance requirements for new motor vehicles and items of motor vehicle equipment. NHTSA is not authorized to certify or approve motor vehicles or motor vehicle equipment for compliance with our Federal motor vehicle safety standards. Instead, under the National Traffic and Motor Vehicle Safety Act (copy enclosed), each manufacturer of a motor vehicle or item of motor vehicle equipment is responsible for certifying that its products meet all applicable safety standards. The following represents our opinion based on the information provided in your letter. There is currently no Federal motor vehicle safety standard that is directly applicable to a removable console-armrest sold directly to a consumer as an item of 'aftermarket' equipment. However, under Federal law you are considered a manufacturer of motor vehicle equipment, and are therefore subject to the requirements in sections 151-159 of the Safety Act concerning the recall and remedy of products with defects relating to motor vehicle safety. I have enclosed an information sheet that briefly describes those responsibilities. In the event that you or NHTSA determines that your products contain a safety related defect, you would be responsible for notifying purchasers of the defective equipment and remedying the problem free of charge. Safety Standard No. 201, Occupant Protection in Interior Impact, and No. 302, Flammability of Interior Materials, apply to new completed motor vehicles and set performance requirements for consoles and armrests installed on new motor vehicles prior to the vehicle's first sale to a consumer. While these standards do not apply directly to a console-armrest sold only as aftermarket equipment, installation of your product on both new and used vehicles may give rise to certain responsibilities on the part of any commercial business making the installation. A manufacturer of a new vehicle installing your product on the vehicle prior to the vehicle's first sale to a consumer would be required to certify that the vehicle complies with all applicable Federal motor vehicle safety standards, including Standard No. 201. Paragraph S3.3 of the standard requires interior compartment door assemblies located in a console assembly to remain closed under certain test conditions. The purpose of the requirement is to prevent a door from flying open and striking an occupant in a crash. The door in your console would have to meet this requirement if your product is installed on a new vehicle prior to the vehicle's first sale. Your product would also have to comply with Standard No. 201's requirements for armrests specified in paragraph S3.5 of the standard if your console-armrest is installed in a new motor vehicle prior to the vehicle's first sale to a consumer. Standard No. 302 specifies burn resistance requirements for certain vehicle components, including arm rests and compartment shelves. A vehicle manufacturer installing your product on a new vehicle would also have to ensure that the fabric on your console-armrest burns at a rate within the limits specified in the standard. I have enclosed copies of both Standards No. 302 and No. 201 for your information. Section 108(a)(2)(A) of the Safety Act specifies that no manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative any device or element of design installed on or in a motor vehicle in compliance with an applicable Federal motor vehicle safety standard. This means that none of the persons mentioned could install your product in a new or used vehicle if the installation would destroy the vehicle's compliance with applicable Federal safety standards. For example, the flammability resistance of the original vehicle is an element of design installed in a motor vehicle in compliance with Standard No. 302. Thus, a manufacturer, distributor, dealer or motor vehicle repair business could not install a console-armrest that does not comply with Standard No. 302 in a new or used motor vehicle since to do so would render inoperative that element of design, and thus violate 108(a)(2)(A) of the Act. Section 109 of the Act specifies a civil penalty of up to $1,000 for each violation of 108. In summary, your console-armrests that are sold to motor vehicle owners as items of aftermarket equipment are not subject to any Federal motor vehicle safety standard. The console-armrest could be subject to Federal standards for occupant interior and flammability protection if it is installed on new vehicles prior to the vehicle's first sale. Commercial businesses are prohibited from installing the console-armrest on new or used vehicles if the result renders inoperative the compliance of requisite safety components or designs with Federal safety standards. Individual owners, however, are not covered by 108(a)(2)(A) and may themselves install your product in their vehicles without regard to the rendering inoperative prohibition of the Safety Act. To repeat, you as the equipment manufacturer would be obligated to recall and remedy your products that contain a defect related to motor vehicle safety, even if the console-armrest were installed by vehicle owners themselves. I hope this information has been helpful. Please feel free to contact us if you have further questions. Sincerely, Erika Z. Jones Chief Counsel Enclosures";

ID: nht73-6.16

DATE: 02/07/73

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Oshkosh Truck Corporation

TITLE: FMVSR INTERPRETATION

TEXT: This is in response to your letter of January 31, 1973, in which you asked us to confirm your "understanding that FMVSS No. 121 will not apply to fire-fighting vehicles until 1 September 1976, two years from the effective date." In general, you suggest that "we would expect to comply with FMVSS [for firefighting vehicles] within two years after the effective date or two years from the date of publication of the FMVSS, whichever date occurs later".

You have misread the relevant language of 49 CFR @571.8. That section provides that the effective date of a standard as applied to firefighting vehicles is "either 2 years after the date on which such standard or amendment is published in the Rules and Regulations section of the Federal Register, or the effective date specified in the notice, whichever is later", except as otherwise specified in the standard with reference to those vehicles. The alternatives are thus (a) 2 years after the publication date, or (b) the effective date, whichever is later -- not 2 years after the effective date, as you have read it.

Your reading would not be reasonable; since the effective date cannot be before the publication date, there would be no point to the alternative phrasing.

ID: nht68-2.50

DATE: 04/16/68

FROM: AUTHOR UNAVAILABLE; David A. Fay; NHTSA

TO: Hercules Galion Products, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of March 15, 1968, to the Director, National Highway Safety Bureau, concerning your interpretation of the requirements of Motor Vehicle Safety Standard No. 108.

The lamps and reflectors shown on your drawing(Illegible Words) dated March 8, 1968 appear to be in conference with the requirements of Initial Standard No. 108; however, since no dimensions are specified on your drawing, we can only assume that the locations are as specified in the standard.

The certification requirements for complete vehicles incorporating chassis and bodies manufactured prior to and after January 1, 1968, are correctly stated in the information bulletin attached to your referenced letter and dated March 15, 1968.

With respect to the requirements of Standard No. 108, I must point out that this Bureau does not issue approvals on items of lighting equipment or on vehicle designs incorporating this equipment. Therefore, the above comments are for your information only, and in no way relieve the vehicle manufacturer from his responsibility for certifying that the assembled vehicle meets the requirements of Standard No. 108.

ID: nht69-2.15

DATE: 12/16/69

FROM: AUTHOR UNAVAILABLE; C. A. Baker; NHTSA

TO: Fiat Motor Company, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of November 20, 1969, to Mr. Francis Armstrong, concerning your proposed windshield wiper system.

We assume your new windshield wiping system will meet the requirements of S4.1.1.3 of Motor Vehicle Safety Standard No. 104, based upon your description of its operation. Note that S4.1.1.3 states "the highest and one lower frequency" -- the fact that you have even a lower frequency, to cycles per minute, does not conflict with this requirement. The main thing is you do offer a frequency differential of at least 15 cycles per minute measured from a low frequency of at least 20 cycles per minute.

With respect to the requirements of Standard No. 104, I must point out that this Bureau does not issue approvals of windshield wiper systems or on vehicle designs incorporating this equipment. Therefore, the above comments are for your information only and in no way relieve the vehicle manufacturer from his responsibility for certifying that the assembled vehicle meets the requirements of the standard.