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NHTSA Interpretation File Search

Overview

NHTSA's Chief Counsel interprets the statutes that the agency administers and the standards and regulations that it issues. Members of the public may submit requests for interpretation, and the Chief Counsel will respond with a letter of interpretation. These interpretation letters look at the particular facts presented in the question and explain the agency’s opinion on how the law applies given those facts. These letters of interpretation are guidance documents. They do not have the force and effect of law and are not meant to bind the public in any way. They are intended only to provide information to the public regarding existing requirements under the law or agency policies. 

Understanding NHTSA’s Online Interpretation Files

NHTSA makes its letters of interpretation available to the public on this webpage. 

An interpretation letter represents the opinion of the Chief Counsel based on the facts of individual cases at the time the letter was written. While these letters may be helpful in determining how the agency might answer a question that another person has if that question is similar to a previously considered question, do not assume that a prior interpretation will necessarily apply to your situation.

  • Your facts may be sufficiently different from those presented in prior interpretations, such that the agency's answer to you might be different from the answer in the prior interpretation letter;
  • Your situation may be completely new to the agency and not addressed in an existing interpretation letter;
  • The agency's safety standards or regulations may have changed since the prior interpretation letter was written so that the agency's prior interpretation no longer applies; or
  • Some combination of the above, or other, factors.

Searching NHTSA’s Online Interpretation Files

Before beginning a search, it’s important to understand how this online search works. Below we provide some examples of searches you can run. In some cases, the search results may include words similar to what you searched because it utilizes a fuzzy search algorithm.

Single word search

 Example: car
 Result: Any document containing that word.

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 Example: car seat requirements
 Result: Any document containing any of these words.

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 Example: car AND seat AND requirements
 Result: Any document containing all of these words.

 Note: Search operators such as AND or OR must be in all capital letters.

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 Example: "headlamp function"
 Result: Any document with that phrase.

Conjunctive search

Example: functionally AND minima
Result: Any document with both of those words.

Wildcard

Example: headl*
Result: Any document with a word beginning with those letters (e.g., headlamp, headlight, headlamps).

Example: no*compl*
Result: Any document beginning with the letters “no” followed by the letters “compl” (e.g., noncompliance, non-complying).

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Example: headlamp NOT crash
Result: Any document containing the word “headlamp” and not the word “crash.”

Complex searches

You can combine search operators to write more targeted searches.

Note: The database does not currently support phrase searches with wildcards (e.g., “make* inoperative”). 

Example: Headl* AND (supplement* OR auxiliary OR impair*)
Result: Any document containing words that are variants of “headlamp” (headlamp, headlights, etc.) and also containing a variant of “supplement” (supplement, supplemental, etc.) or “impair” (impair, impairment, etc.) or the word “auxiliary.”

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Displaying 1701 - 1710 of 2067
Interpretations Date

ID: nht94-7.32

Open

DATE: March 21, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Lawrence P. White -- Acting Director, Bureau of Motor Vehicles, Dept. of Transportation, Commonwealth of Pennsylvania

TITLE: None

ATTACHMT: Attached to letter dated 12/13/93 from Lawrence P. White to Mary Versie (OCC-9479)

TEXT:

This responds to your letter of December 13, 1993, asking several questions concerning a recent amendment to Standard No. 217, Bus Emergency Exits and Window Retention and Release (57 FR 49413; November 2, 1992). Your questions and the response to each follows.

1. The effective date - is it the chassis manufacturer's date of completion, the final stage manufacturer's date of completion, or somewhere in between?

The effective date for the November 2 final rule is May 2, 1994. Only vehicles manufactured on or after the effective date of an applicable requirement in a Federal motor vehicle safety standard must comply with that requirement. If a vehicle is manufactured in two or more stages, the final stage manufacturer is required to certify that the vehicle complies with "the standards in effect on the date of manufacture of the incomplete vehicle, the date of final completion, or a date between those two dates." (49 CFR Part S568.6).

2. Based on the formula for emergency exit space, is the area of the front service door to be included? Does this mean on a vehicle of 60 to 77 passengers, the only additional requirements beyond the front and rear doors is a left side exit door?

The November 2 final rule requires additional emergency exit area (AEEA) for some buses. The amount, if any, of AEEA which must be provided is determined by subtracting the area of the front service door and either the area of the rear emergency door or the area of the side emergency door and the rear push-out window, depending on the configuration of the bus (S5.2.3.1). These are the minimum exits required on all buses. If AEEA is required, the first additional exit which must be installed is a left side emergency door (for a bus with a rear emergency door) or a right side emergency door (for a bus with a left side emergency door and a rear push- out window). The number of exits may vary for buses which carry the same number of passengers, because the amount of area credited for each exit is the area of daylight opening, and because different variations of types of exits are possible. However, in the regulatory evaluation for the final rule, the agency estimated that a bus would not be required to have a roof exit (the second type of additional exit required) unless the capacity was greater than 62 (for a bus with a rear emergency door) or 77 (for a bus with a left side emergency door and a rear push-out window).

3. The "clear aisle space" required for exit to the proposed side

emergency door, according to federal specifications, can be met with a flip-up type seat or a clear opening of 12", as measured from the back of the door forward. Are there any specifications, definitions, or descriptions provided as to what would be considered a "flip seat"?

The November 2 final rule allowed a flip-up seat to be adjacent to a side emergency exit door "if the seat bottom pivots and automatically assumes and retains a vertical position when not in use, so that no portion of the seat bottom is within" the required 12 inch aisle to the exit (S5.4.2.1(a)(2)(ii)). The agency did not otherwise define a flip-up seat, nor did it include any performance requirements for these seats.

4. Also, there is concern regarding school buses that are equipped with the "flip seat" by the emergency door opening and the possibility of school children, either intentionally or accidently, unlatching the door latch mechanism. Are the door latch mechanisms to be equipped to help prevent this from occurring?

Standard No. 217 includes requirements for the type of motion and force required to release an emergency exit (S5.3.3). One of these requirements is that the notion to release a door must be upward from inside the bus (upward or pull-type for school buses with a gross vehicle weight rating of 4,536 kilograms or less). This is intended to lessen the chance of a door accidently being opened, without unnecessarily making the exit more complicated to open in an emergency. In addition, warning alarms are required for door and window exits to notify the driver that the exit has been opened.

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: nht73-5.21

Open

DATE: 09/19/73

FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA

TO: Pundalik K. Kamath

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letters of August 7 and August 23, 1973, concerning the conformity to Standard No. 121 of certain features in air brake systems submitted to you by suppliers.

Your first question is whether the volume of a supply reservoir that lacks a check valve is to be included in arriving at the required reservoir volume of 12 times the full-travel service brake chamber volume. Our reply is that S5.1.2.1 includes the volume of all service and supply reservoirs, regardless of valving, and that the volume of the supply reservoir in question would therefore be included in the combined reservoir volume.

You next ask whether a system that has no isolated emergency reservoir can rely on its service reservoirs to provide air for the two emergency stops proposed as S5.7.3 by Docket No. 73-13, Notice 1 (38 F.R. 14963). Under this proposal, the stops would have to be accomplished with a single failure of a part (other than a common valve, manifold, brake fluid housing or brake chamber housing) designed to contain compressed air or brake fluid. If the system is designed so that no single failure, other than a valve, manifold, or housing failure, will cause a loss of air in both tanks, it would seem to be capable of meeting the proposed requirement even though it does not have an isolated emergency reservoir. However, if a single failure in a brake line would deplete the air in both service reservoirs, the system would be unable to meet S5.7.3 unless an emergency isolated reservoir were provided.

2

In answer to your last question, the emergency stops proposed in S5.7.3 would be conducted from an initial pressure in excess of the compressor cut-in pressure. The reservoirs would not be depleted by prior stops.

Yours truly,

August 7, 1973

Lawrence Schneider Chief Counsel National Highway Traffic Safety Administration

Enclosed are schematic copies of air brake systems provided to OTC by Berg Manufacturing Company and Bendix-Westinghouse Air Brake Division which illustrate air brake systems incorporating provision for secondary brakes per the Notice of Proposed Rulemaking, Docket 73-13, Notice 1.

Our concern is if these systems, which are essentially the same, will meet the proposed change to FMVSS 121 when effective, particularly paragraph S5.7.3 as proposed? While we see no reason they would not OTC would like an opinion from your office before we adopt either system.

We would like said opinion as soon as conveniently possible to assist in our brake program execution. Thank you.

OSHKOSH TRUCK CORPORATION

Pundalik K. Kamath Senior Safety Engineer

Enclosures

August 23, 1973

Lawrence Schneider Chief Counsel National Highway Traffic Safety Administration

With reference to my letter dated, August 7, 1973, regarding compliance of the air brake systems proposed by Berg Manufacturing Company and Bendix-Westinghouse Air Brake Division with FMVSS 121 per Proposed Rulemaking, Docket 73-13, Notice 1, particularly with respect to the following questions, I would like to receive clarification from you.

1. Is it correct to use the supply reservoir volume, which is not protected by a check valve, when calculating the total volume of twelve times full stroke chamber volume? Our assumption is that this is acceptable however, we would like confirmation.

2. These systems have no isolated emergency reservoir and rely on air pressure from one of the two service reservoir sources, assuming a failure in the other service reservoir source, for the minimum two stop capability in modulated emergency mode. This implies a single failure affecting only one service reservoir system, it is our understanding that this is acceptable practice per the proposed standard. Please confirm.

3. We understand that a modulated emergency stop condition implies a fully charged service reservoir, that is 100-110 psi in the functional reservoir, that no normal stops which temporarily drop this pressure to 80-90 psi immediately prior to the failure condition are considered. In the latter case two modulated emergency stops may not be obtainable due to the lowered pressure. Please confirm that the baseline condition assumes at least one service reservoir is normally charged to 100-110 psi before simulating failure.

We would appreciate your reply to these questions, as soon as conveniently possible.

OSHKOSH TRUCK CORPORATION

PUNDALIK K. KAMATH Senior Safety Engineer

ID: 77-3.30

Open

TYPE: INTERPRETATION-NHTSA

DATE: 07/18/77

FROM: AUTHOR UNAVAILABLE; Robert L. Carter; NHTSA

TO: Michelin Tire Corporation

TITLE: FMVSR INTERPRETATION

TEXT: This responds to Michelin's March 23, 1977, letter concerning its February 20, 1976 petition for reconsideration of Standard No. 120, Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars. Your petition for reconsideration was responded to on February 7, 1977 (42 FR 7140). By this letter, you attempt to resubmit your petition for reconsideration.

Petitions for reconsideration must be received by the agency within 30 days of the publication of a notice. Since the resubmission of your petition is untimely, it has been considered a petition for rulemaking as required by Part 553.35 of our regulations (Code of Federal Regulations, Volume 49). The National Highway Traffic Safety Administration (NHTSA) denies your requested rulemaking.

Your petition suggests that consumers will be confused by the tire label information if the vehicle is not equipped with the tires identified on the label. The agency has determined that confusion will be minimized by the use of the optional heading "Suitable Tire-Rim Choice."

Your petition raises a second problem concerning tires of identical size designations manufactured by different companies. These tires may have different inflation pressures even though their sizes are identical. The agency understands that this difference in inflation pressure could result in confusion. Manufacturers, however, can avoid this problem through the use of the manufacturer's name on the tire information label as part of the tire information. Use of the manufacturer's name on the label should distinguish between two otherwise similar tires.

SINCERELY,

MARCH 23, 1977

Docket Section National Highway Traffic Safety Administration

Re: Petition for Reconsideration

Docket No. 71-19; Notice 6

Part 567 - Certification

Docket No. 75-32; Notice 2

Part 571 - Federal Motor Vehicle Safety Standard 120 Tire Selection and Rims for Motor Vehicles other than Passenger Cars We are writing regarding your response to our petition for re-consideration of FMVSS 120 which we submitted February 20, 1976, wherein we requested deletion of the requirement that tire information appear on the certification label. It is our contention that many consumers upon seeing this label will be led to believe that the tires listed are the only tires that can be legally used on the vehicle and that the inflation pressures on the label are the required operating pressures for the tires.

In addition, the inclusion of tire pressures on the FMVSS 120 certification label will be especially confusing since tires of the same size designation can require different pressures for the same load carrying capacity.

In the response to our petition, which appeared in the Federal Register Vol. 42, No. 25 dated Monday, February 7, 1977, it is stated that it is the agency's view that any possibility of confusion can easily be avoided by an indication that the tire designation represents a radial tire, so that a person substituting a non-radial tire size with the same designation is aware that the two tires are not identical.

However, we wish to point out to the agency that we were not only referring to tires of different constructions but also to tires of the same construction. For example, a Michelin 10.00R20 LR G radial tire carrying a tire load of 6040 lbs. requires 100 psi whereas a 10.00R20 LR G radial tire standardized by the American Tire and Rim Association requires 105 psi for the same load.

Since FMVSS 119 does not require tires of the same size designation to have identical load/inflation values, the fact is that many Michelin tires have different pressure requirements than T&RA tires of the same size -- designations, even though they are both radial tires. This fact could, in some cases, cause users to underinflate their tires based on the inflation pressure indicated on the certification label.

We therefore re-submit our petition for re-consideration and once again urge the agency to reconsider the necessity of requiring information on the certification label that will lead to a great deal of confusion. We request that the requirement that tire information appear on the certification label be deleted.

MICHELIN TIRE CORPORATION Technical Group

John B. White Engineering Manager Technical Information Dept.

ID: 77-4.9

Open

TYPE: INTERPRETATION-NHTSA

DATE: 09/29/77

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

TO: Thomas Built Buses, Inc.

TITLE: FMVSS INTERPRETATION

ATTACHMT: Attached to letter dated 7-5-84 from F. Berndt to R. Marion; Also attached to letter dated 3-23-90 from A.H. Brett to M.B. Mathieson; Also attached to letter dated 12-3-90 from P.J. Rice to M.B. Mathieson (A36; Std. 217); Also attached to letter dated 3-26-90 from M.B. Mathieson to E.Z. Jones (OCC 4598); Also attached to letter dated 3-30-90 from M.B. Mathieson to M.F. Trentacoste; Also attached to letter dated 8-8-89 from M.F. Trentacoste to K. Finkel

TEXT: This responds to your August 25, 1977, letter asking several questions about the applicability of Standard No. 217, Bus Window Retention and Release, to buses other than school buses.

Your first state your conclusion that paragraph S5.2 of the standard applies only to buses other than school buses. Your interpretation of S5.2 is correct. Secondly, you state that S5.2.1 applies to all buses with GVWR's of more than 10,000 pounds. This assertion is incorrect. See S5.2.3. Paragraph S5.2.1 applies only to buses other than school buses that have GVWR's greater than 10,000 pounds.

Your final inquiry pertaining to Standard No. 217 concerns the requirement for unobstructed emergency exits in both school and non-school buses. You first correctly state that paragraphs S5.4 through S5.4.2.1 describe the required size of the unobstructed openings for school buses. You then claim that there is no equivalent description for the size of unobstructed openings required in buses other than school buses. This last statement is not entirely accurate. The amount of unobstructed emergency exit openings required for buses other than school buses is detailed in S5.2. This section establishes requirements for the total area of unobstructed emergency exit openings and for the location of those exits. This section also specifies the extent to which the area of each exit is to be counted in determining compliance with the total unobstructed opening requirement. Therefore, although the standard does not specify minimum size requirements for individual exits in buses other than school buses, the standard does contain other requirements for unobstructed openings in buses other than school buses.

You concluded in your letter that buses other than school buses are not required to use the parallelepiped device in determining whether their rear exits comply with the requirements. This conclusion is accurate. For purposes of clarity, however, you should note that Standard No. 217 does not mandate rear doors in buses other than school buses. Those buses can utilize either rear exits or roof exits. Further, regardless of the fact that you use a rear emergency door in buses other than school buses, you must insure that you also provide the other mandatory exits and the correct area of unobstructed openings as described in paragraphs S5.2 through S5.2.2.

SINCERELY,

Thomas BUILT BUSES, INC.

August 25, 1977

Office of The Chief Counsel U. S. Department of Transportation

Attn: Roger Chilton

The purpose of this letter is to request an interpretation of FMVSS No. 217 regarding the range of it's application, as follows: Para.S.5.2 - Speaks to buses other than schoolbuses and requires "unobstructed" openings for emergency exit . . ." going on to define the area requirements.

Para.S.5.2.1 - Speaks to "Buses with GVWR of more than 10,000 pounds". This presumably covers all buses. It further states that ". . . buses with a GVWR of more than 10,000 lbs. shall meet the unobstructed openings requirement by providing . . . one rear exit that conforms to S.5.3 through S.5.5".

Under paragraph S.5.4 thru S.5.4.2.1.(a) as amended May 25, 1976, the unobstructed opening of a school bus is described as "an opening large enough to permit unobstructed passage of a rectangular parallelepiped 45 inches high, 24 inches wide and 12 inches deep, keeping . . .". There is no description that pertains to the unobstructed opening of a non-school bus.

We have, therefore, decided that the non-school bus needs only a 12 inch wide clear aisle opening at the rear door to meet the requirements of FMVSS 217. Is this interpretation correct?

We would appreciate an early answer to this query.

Malcolm B. Mathieson, Engineering Manager

ID: 77-5.1

Open

TYPE: INTERPRETATION-NHTSA

DATE: 12/12/77

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

TO: Mrs. Edward Foster

TITLE: FMVSR INTERPRETATION

TEXT: Your recent letter to President Carter concerning the installation of a bench seat in a cargo van was forwarded to the National Highway Traffic Safety Administration for reply. You were apparently told by your local Ford dealer that Federal law prohibits the installation of a seat in the cargo area of a van vehicle.

The Ford dealer's representation to you was incorrect. There is no Federal law that precludes installation of a seat such as your letter describes; although, depending on the time and manner of the installation, the seat might be subject to Federal safety standards.

If the vehicle manufacturer (Ford) or your dealer installs the seat prior to the time you take possession of the vehicle, either will have to certify that the vehicle, including the seat, is in compliance with all applicable safety standards, as provided in the National Traffic and Motor Vehicle Safety Act, as amended (15 U.S.C. 1381 et seq.). Specifically, the installation of the seat would require compliance with Safety Standard No. 207, Seating Systems, Safety Standard No. 208, Occupant Crash Protection, and Safety Standard No. 210, Seat Belt Anchorages. If done by your dealer, he would be required to attach a label or tag to the vehicle certifying that, as altered, the vehicle was in compliance with all safety standards, including the three just mentioned (49 CFR 567.7).

If you first take possession of the vehicle, you or your dealer may then install an additional seat without certifying compliance with Federal safety standards (15 U.S.C. 1397). Your dealer would, however, be subject to section 108 (a)(2)(A) of the Vehicle Safety Act, which provides that 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 means that the dealer would not be permitted to destroy the vehicle's conformity to any safety standard by his installation of the additional seat. We do strongly recommend that, for the safety of your child, you assure the seat and safety belts conform to the minimum performance requirements of our safety standards.

Perhaps it is the policy of Ford Motor Company and its dealers not to install additional seats in cargo vans because of the responsibilities mentioned above. The policy is not, however, a Federal law. I suggest you show this letter to your local dealer.

SINCERELY,

President Jimmy Carter

Dear Mr. President:

My husband will be starting a new independent business within the next several weeks that requires him to use a cargo van. We have ordered a 1978 Ford van and need a standard back seat directly behind the driver area. We were told it was a newly passed Federal law that prohibits the installation of a seat in the cargo area. Having exhausted our efforts locally and within our area, we are now in a position to seek assistance from the only person left to aid us in acquiring a seat for our van.

We are the parents of a severely retarded child twelve years of age who is unable to sit normally in a regular seat. We therefore are left to improvise by seat-belting him into a standard seat for transporting him from the various places in the reclinger position.

As I am employed in a part-time position in Delivery, ten miles from our home, it is necessary to use the van on those days for his father to bring him home while I work.

We are therefore requesting your assistance in acquiring a seat for our van by authorizing the Ford Motor Company to install a seat behind the driver equipped with seat belts for the convenience of a handicapped child Please consider this special privilege we are requesting and it is our hope that placing yourself in the same position you will be able to understand the plight.

Your simple attention to this request will be greatly appreciated as our order has not been processed as of this date and we need your authorization to complete our order.

Thanking you in advance.

Mary Edwards Foster

P.S Our order was placed with the Reavis Ford, Inc.

January 21, 1975

To Whom It May Concern:

Christopher Lee Foster, son of Mr. & Mrs. Edward L. Foster is severly physically and mentally retarded with I Q definitely under 40.

Hilda H. Bailey, M. D.

ID: nht75-4.22

Open

DATE: 04/03/75

FROM: AUTHOR UNAVAILABLE; J. C. Schultz; NHTSA

TO: Ventline, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of February 27, 1975, regarding the use of rubber-modified polypropylene plastic in a roof ventilator which you manufacture. You enclose a sample of the material.

A plastic material used in the roof ventilator of a motor home must meet the requirements of Motor Vehicle Safety Standard No. 205 (49 CFR @ 571.205). Our conclusion is based on the fact that ANS Standard Z26.1-1966, which is incorporated into the Federal standard, includes ventilators and openings in the roof of motor vehicles as locations in which glazing materials meeting the requirements of the standard are directed to be used. Any of the materials specified in ANS Z26, and the plastic materials added to the standard (items 12 and 13) on November 11, 1972, may be used in a roof ventilator of a motor home. We would consider such a ventilator to be a "window" of the motor home.

The NHTSA has in the past amended Standard No. 205 to permit the use of new materials in vehicle locations following a manufacturer's petition for such an amendment. It appears from your letter that the use of polypropylene in roof ventilators would not create a safety hazard. However, in order for us to consider a change in the standard it will be necessary for you to provide us with information on the performance of this material. One way that manufacturers have provided us this information in the past is to have the material tested to the least restrictive requirements of the standard for any material which the standard permits to be used in the location desired.

I have enclosed a copy of NHTSA procedural rules (49 CFR Part 523) containing information on submitting a petition for rulemaking. Such a petition should contain the information I have referred to regarding the performance of polypropylene.

In your letter you ask for a code number should we determine that the material must conform to Standard No. 205. A code number, however, is issued only to a prime glazing material manufacturer, who is one who either fabricates, laminates, or tempers the glazing material. The request for such a code number must be made directly by the prime glazing material manufacturer.

Sincerely,

ATTACH.

February 27, 1975

Chief Counsel -- National Highway Traffic Safety Administration

Ref: F.M.V.S.S. 205

Gentlemen:

Ventline, Inc. is a manufacturer of roof ventilators for motor homes and campers. We are trying to determine if F.M.V.S.S. #205 applies to our product. (literature enclosed.)

The purpose of this standard mentions, (1) injuries from impact with glazing surfaces, (2) ensurance of driver visibility in motor vehicle windows, (3) minimize possibility of occupants being thrown through windows in collisions.

(1 & 3) As far as injuries from impact go, the possibility of contact with the dome in a collision is very remote since the opening in the unit is only 12 inches square and that area is blocked by a heavy gage steel bar across the opening which makes it most difficult to come into direct contact with the plastic dome.

(2) The concern of transparency and driver visibility is completely unrelated to the intent of the vent. It is installed in the roof of the vehicle, not one of the adjacent sides to areas occupied by persons, and is used primarily for ventilation. It also allows a limited amount of light through the "TRANSLUCENT" not transparent dome. It's intent was not to provide visibility through the roof.

The material used in this dome is a rubber modified polypropylene plastic which has superior impact resistance. As you can see by the small sample I have enclosed, it also has a good degree of flexibility to resist breakage.

To the best of our knowledge, there isn't any glazing being done with polypropylene because of the difficulty of obtaining good transparency, so it doesn't seem to us that our dome should be considered glazing material and shouldn't have to comply with F.M.V.S.S. #205.

If in your opinion, after considering these points, you feel that we must comply with #205, please consider this our application for a manufacturers code mark.

We are eagerly awaiting your decision on this matter.

Sincerely,

VENTLINE, INC. -- Dave Bickel, Product Engineering

enclosure

cc: Harry Hunt; Ernie Baker

ID: nht75-1.1

Open

DATE: 11/26/75

FROM: AUTHOR UNAVAILABLE; James B. Gregory; NHTSA

TO: Libby-Owens-Ford Company

TITLE: FMVSS INTERPRETATION

TEXT:

N41-42

H. M. Alexander, Vice President Technical Development & Services Libbey-Owens-Ford Company 1701 East Broadway Toledo, Ohio 43605

Dear Mr. Alexander:

This is a further reply to your letter of September 11, 1975, requesting an interpretation of the test procedures for measuring light transmission of glazing materials in accordance with Federal Motor Vehicle Safety Standard No. 205, Glazing Materials.

As you know, the purpose of the luminous transmittance requirement is to assure that safety glazing used in motor vehicles at levels requisite for driving visibility, does not restrict the vehicle operator's vision below that necessary for safe operation. Further, the apparent effective luminous transmittance of safety glazing as viewed by the human eye is the average transmittance of the entire area surveyed by the eye. In view of this, the National Highway Traffic Safety Administration would not consider glazing with an average luminous transmittance over its entire area of 70 percent or more to be in non-compliance with the standard.

As you pointed out, the luminous transmittance test procedure specified by Standard No. 205 does not specify the diameter of the measuring light beam. Thus, you are free to use any diameter light beam that is appropriate.

In regard to the distinct bend lines in your back window, we would consider for purposes of determining luminous transmittance, your back window to be divided into three sections - two wings and the central section. Thus, in this case, the distinct bend lines would not be considered as glazing material.

Sincerely,

James B. Gregory Administrator

September 11, 1975

Dr. James B. Gregory, Administrator National Highway Traffic Safety Administration Nassif Building Washington, D.C. 20590

Dear Dr. Gregory:

On August 25, we met at the Department of Transportation with Messrs. Guy Hunter, Doug Pritchard and Chuck Kaehn and discussed a new type automotive backlight.

This new type backlight offers advantages toward greater safety by better rear visibility with minimal optical distortion. However, we questioned whether this type backlight meets the 70% light transmission requirement of the ANSI Code Z26 which is a requirement of FMVSS 205.

This new backlight achieves its advantages as the result of bending sharply around a "hot line" electrical conductor which results in a .190" wide opaque line at the boundary between the intersecting bent glass surfaces. In the heated version of such a backlight, the conducting lines in the wing areas are only 17/32" apart whereas in the central area of the backlight, the lines are 1-1/8" apart. See attached sketch of "hot line bent" back window dated September 5, 1975.

The ANSI Code which requires that such an automotive backlight have a light transmission above 70%, does not specify the diameter of the measuring light beam or its placement on the backlight. In the backlight discussed here, if a 1-1/4" diameter measuring beam is used and positioned with one heating line centered in the beam in the central or major rear vision area, it meets the 70% requirement, see Figure 1 in the attached memorandum by Paul Mattimoe dated September 5, 1975. However, if two heating lines are located symmetrically within the same beam as shown in Figure 3 in attached memo, the transmission does not meet the code requirement.

Therefore, we respectfully request that the NHTSA provide an interpretation which will recognize that this improved design of backlight meets the intent of FMVSS 205. Specifically we would suggest that the interpretation specify the positioning of one frit conductor line centered in the light beam as shown in Figure 1 of the attachment. This orientation will provide additional objectivity in the test conditions while the 70% transmissibility requirement will continue to limit the amount of abscuration which could be caused by the electrical conductors. In addition, we suggest that transmission measurements should not be required at the boundaries formed by the intersection of any two glazing surfaces.

We will appreciate your consideration of this request. We will be glad to meet at DOT offices again if advisable. It is urgent that a decision be received since production tooling for the car model involved in this request is proceeding at the present time.

Very truly yours,

H. M. Alexander Vice President Technical Development & Services

HMA:pjp

Attachments

ID: nht73-4.6

Open

DATE: 04/10/73

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Independent Tire Dealer

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of February 26, 1973, requesting our view of your booklet on Standard No. 117. We have the following comments.

On page 2, under the heading, "Does a Retread Have to Pass All These Tests", you refer to a lack of availability of test wheels. On page 3, under the heading, "How Expensive Could Testing Get?", you quote figures of $ 250.00 to $ 400.00. As you know, the standard no longer includes the high speed and endurance tests, and while there are other laboratory tests involved in testing strength and bead unseating, neither includes the use of the laboratory test wheel. Consequently, insofar as your statements may take into account laboratory wheel tests, they should be modified.

On page 3, under the heading, "What if One Certified Doesn't Comply?", you state, "If the tire was not produced with due care then you will have both a recall and the probability of a penalty being assessed." Notification of defects to first purchasers however, is not contingent upon a showing of due care, and must be made even if a manufacturer used due care. Whether a manufacturer exercises due care is relevant only to whether he is in violation of the Act, and to civil penalties, but not to defect notification (recall). The reason is that a retreader's exercise of due care doesn't change the fact that potentially unsafe tires will be used unless their owners are notified.

On page 4, under the heading, "Must You Submit Information On Defects and Failures?": Under section 113(d) of the National Traffic and Motor Vehicle Safety Act (as amended in 1970), each retreader must furnish NHTSA with a true and representative copy of all notices, bulletins, or other communications sent either to dealers or purchasers with regard to any defect in his tires. This requirement applies to all defects, and you should review it. It is incorrect to say that retreaders are not required to submit information regarding defects to NHTSA.

On page 4, under "What Casing Controls are Required?", you indicate that no tire may be retreaded which has exposed ply cord. However, the standard allows ply cord to be exposed at a splice (S5.2.1(b)). While you make this point later, on page 5, the way in which you do so seems more to contradict than clarify your earlier statement. We suggest you indicate that ply cord may be exposed at a splice in the earlier paragraph as well. The same thing can be said for the next section on page 4, "May Tires With Exposed Ply Cord be Retreaded?". This section is also completely silent on the exception for ply cord at a splice, and should also be modified.

On page 4, under the heading, "What are Restrictions on Good Casings?", you omit certain requirements. Casings without a symbol DOT that are to be retreaded must only be of those size designations specified in the table at the end of the standard. These casings must also have permanently labeled on them the size, and number of plies or ply rating. Both of these information items and the symbol "DOT" must also be permanently labeled on each DOT casing that is to be retreaded.

On page 5, under the heading, "Should We Use Affixed Labels or Permanent Molding On Tire?", the minimum size for permanent labeling under S6.3.2 has been changed to 0.078 inches. This change does not, however, affect affixed labels.

On page 6, under the heading, "Is Any Provision Made For Sizing Difference in Retreads?", you state a retread may be 10% over new tire physical and dimension requirements. The 10% allowance for section width is to be calculated on the section width specified in the Tables of Standard No. 109, for the tire size designation. New tires are allowed to exceed this figure by 7%. Consequently, retreads can exceed the new tire requirement by only 3%(Illegible Word) of the table figure). To say they can exceed the new tire requirement by 10% may mislead some persons into thinking they can exceed the value in the table by 17% which, of course, is not correct.

Apart from these points, your booklet appears to us to be essentially correct. It should prove helpful to retreaders.

ID: nht72-4.45

Open

DATE: 03/24/72

FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA

TO: Blue Bird Body Company

TITLE: FMVSR INTERPRETATION

TEXT: This is in response to your letter of February 7, 1972, in which you discussed some problems that you have encountered with the regulation on vehicles manufactured in two or more stages (49 CFR Part 368), as applied to the school buses of which you are the final-stage manufacturer. Since the receipt of your letter, Mr. Rumph of your company and Mr. Sweet of the Truck Body and Equipment Association met with Mr. Dyson of this office to discuss the issues raised in your letter. Also, on March 8 you sent a sample letter that you proposed to send to your customers.

As we understand the problem from your letter and the subsequent discussion, it is essentially that you are receiving chassis-cowls from school bus buyers, for mounting of your bodies as a final-stage manufacturer, which are inadequate for the purpose according to the gross vehicle and gross axle weight ratings now included with the incomplete vehicles under our multistage vehicle regulations, 49 CFR Part 568. The problem as you describe it appears to have arisen in the negotiation between the school bus buyers and the dealers from whom they bought the incomplete vehicles, in that the dealers sold chassis that were too lightly equipped with tires and axles for the loaded weight implicit in the buyer's specification, under both our certification regulations and accepted industry practice. You state that your company bears the immediate burden of the problem, because you have invested in the production of several dozen bodies whose installation is held up pending resolution of the problem.

From your discussion we assume that all parties are agreed that the bodies that the customers ordered (and you have built) are the ones that are to be used, and that the chassis that have been furnished to you can be economically modified to meet the requirements of our regulations and be safe for their intended use.

With these assumptions, we suggest the following course of action on your part:

1. Complete each vehicle as planned.

2. Affix a certification label to each vehicle as you normally do, stating on the label weight rating figures that will satisfy our regulations (Part 567) and the axle capacity requirements of the vehicle.

3. Deliver the vehicle, but concurrently send a written statement by certified mail to the vehicle buyer to the effect that the vehicle must be modified in order to conform to the GVWR and GAWR figures on the certification label, both for purposes of safety and to conform to Federal regulations. The letter should advise the buyer to take the vehicle to a dealer of the chassis manufacturer for these modifications immediately upon receiving it. The sample letter you sent on March 8 will be satisfactory if you modify the second and third paragraphs to read as follows: "Federal Regulation 49 CFR Part 567, Certification, requires Blue Bird to certify the front and rear gross axle weight rating (GAWR) and the gross vehicle weight rating (GVWR) of completed vehicles, and specifies a minimum GVWR based on seating capacity.

"Your vehicle may be shipped as it is, however, the values of GAWR and GVWR shown on the certification plate will be contingent on the chassis modifications indicated above. These changes must, in the interest of safety, be made before the vehicle is placed into service, and you should take the vehicle to your chassis dealer as soon as you receive it."

4. Send copies of each such statement to (a) Office of Standards Enforcement, National Highway Traffic Safety Administration, Washington, D.C. 20590; (b) the manufacturer of the chassis that was delivered to you; and (c) the dealer from whom the buyer ordered the chassis, if any and where known to you.

This procedure is allowed only as to chassis that have already been received by Blue Bird as of the receipt of this letter, and it should not be viewed as precedent for future action by any other persons. In the future, Blue Bird as the final-stage manufacturer must take responsibility for the vehicle as completed by it, to the extent of its knowledge of relevant facts.

We are pleased to be of assistance.

ID: 7768

Open

Mr. C. Morris Adams
1201 Rockford Road
High Point, NC 27260

Dear Mr. Adams:

This responds to your FAX of September 24, 1992, requesting a ruling regarding the legality of lap belts at the passenger seats on school buses. As explained below, Federal law has long required lap or lap/shoulder belts to be installed at every passenger seating position on small school buses. Federal law has also long permitted, but not required, lap or lap/shoulder belts to be installed at passenger seating positions on large school buses, provided that those belts do not adversely affect the large school bus's compliance with the applicable safety standards. This is still the agency's position.

As you know, in 1977, NHTSA issued Federal Motor Vehicle Safety Standard No. 222, School Bus Passenger Seating and Crash Protection, which established minimum levels of crash protection that must be provided for occupants of all school buses. For large school buses (those with a gross vehicle weight rating [GVWR] of more than 10,000 pounds), the standard requires occupant protection through a concept called "compartmentalization" -- strong, well-padded, well-anchored, high-backed, evenly spaced seats. Small school buses (those with a GVWR of 10,000 pounds or less) must provide "compartmentalization" and be equipped with lap or lap/shoulder belts at all passenger seating positions. The agency believes that safety belts are necessary in addition to "compartmentalization" in small school buses because of their smaller size and weight, which are closer to that of passenger cars and light trucks.

Ever since 1977, NHTSA has indicated that Federal law permits lap or lap/shoulder belts to be installed at the passenger seating positions on large school buses as long as the vehicle would still comply with all applicable safety standards, including Standard No. 222. NHTSA has no information to indicate that installation of seat belts at the passenger seating positions on a large school bus would affect the bus's compliance with any safety standard. The allegations in your FAX that using seat belts in large school buses will result in crash forces producing concentrated loading on the head, instead of being spread evenly over the upper torso as is the case without a seat belt, are nearly identical with the explanations included in a 1985 Transport Canada report on school bus safety. NHTSA carefully evaluated and considered the Canadian report and these explanations in connection with its rulemaking action considering whether to specify requirements for voluntarily installed seat belts on large school buses. 54 FR 11765; March 22, 1989. After fully considering the Canadian report, the agency stated at 54 FR 11770:

NHTSA shares commenters' concerns about any implications that safety belts negatively affect the protection provided to passengers on large school buses. However, the agency is not aware of accident data showing an injury caused or made more serious by the presence of safety belts on a school bus. Furthermore, NHTSA cannot conclude from the Canadian report's findings that belts actually degrade the benefits of compartmentalization to the extent that the supplemental restraint system renders inoperative the safety of large school buses, but the possibility exists that the occupant kinematics shown in the Canadian tests could occur.

The agency then identified some possible safety benefits that could result from seat belts in large school buses, benefits that were not considered in the Canadian tests. The agency concluded that, "Although these benefits are not significant enough to justify a Federal requirement for the installation of safety belts on all large school buses, they are enough to provide a basis upon which the agency will decline to prohibit the installation of belts on large school buses." 54 FR 11765, at 11770; March 22, 1989. I have enclosed a copy of this notice for your information.

As you can see, NHTSA has carefully considered the subject raised in your FAX and reviewed all available information in this area. After that review, the agency concluded that there was no justification for changing its longstanding position that persons that wish to do so should be permitted to install seat belts at passenger seating positions in large school buses. Your letter did not provide any data that NHTSA had not already considered. Hence, there is no basis for the agency to change its longstanding position in this area.

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,

Paul Jackson Rice Chief Counsel

Enclosure

ref:222 d:10/9/92

1992

Request an Interpretation

You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:

The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590

If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.

Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.

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