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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.

Multiple word search

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

Connector word search

 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.

Phrase in double quotes

 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).

Not

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.”

Search Tool

NHTSA's Interpretation Files Search



Displaying 391 - 400 of 2067
Interpretations Date

ID: 3301yy

Open

Mr. Robert A. Rogers, Director
Automotive Safety Engineering
Environmental Activities Staff
General Motors Corporation
General Motors Technical Center
30400 Mound Road
Warren, MI 48090-9015

Dear Mr. Rogers:

This responds to your request that this agency determine that the new antitheft device to be installed on the MY 1992 General Motors Pontiac Bonneville line, represents a de minimis change in the system that was the basis for the agency's previous granting of a theft exemption for the car line beginning in MY 1991, and that therefore the Pontiac Bonneville vehicles containing the new device would be fully covered by that exemption. The agency has reviewed the changes to the system and for the following reasons concludes that the differences between the original system and one installed on the MY 1992 Pontiac Bonneville constitute a de minimis change.

As you are aware, the Pontiac Bonneville car line was granted an exemption, pursuant to 49 CFR Part 543, from antitheft marking because General Motors showed that the antitheft device to be used in lieu of marking on the car line was likely to be as effective as parts marking. This antitheft device is known as the "PASS-KEY" antitheft system. The exemption was issued on April 4, 1991, and appeared in the Federal Register on April 9, 1991 (56 FR 14413).

As was stated in the April 1991 Federal Register notice, the "PASS-KEY" antitheft system utilizes an ignition key, an ignition lock cylinder and a decoder module. Before a vehicle can be started, the electrical resistance of a pellet embedded in the shank of the key must be sensed by elements in the lock cylinder and its value compared to a fixed resistance in the decoder module.

In your letter, it was stated that beginning from MY 1992, two design changes were made in the "PASS-KEY" antitheft device that is standard equipment on the Pontiac Bonneville. The new system on the Bonneville is known as "PASS-KEY II," and differs from "PASS-KEY" as follows. First, in "PASS-KEY II," if a key other than the one with proper resistance for the vehicle is inserted, the decoder module will shut down the fuel injector pulses to the engine for three minutes plus or minus eighteen seconds. In "PASS-KEY," this shut down period is two to four minutes. Second, if, during the time the decoder module has shut down in "PASS-KEY II," trial and error attempts are made to start the engine with various keys, the timer will not reset to zero, as is the case with "PASS-KEY." GM states that this difference in functions will provide a similar level of performance as "PASS-KEY" since the "PASS-KEY II" module, while shut down, will ignore further attempts to start the system by means other than use of a key with the proper resistance pellet. Any further unauthorized attempt after the initial three minute shut down time will result in the module shutting down again.

After reviewing the proposed changes to the componentry and performance of the antitheft device on which the exemption was based, the agency concludes that the changes are de minimis. In addition to providing some aspects of performance not provided by the original device, "PASS-KEY II" also continues to provide the same aspects of performance provided by the original device and relies on essentially the same componentry to provide that performance. Therefore, it is not necessary for General Motors to submit a petition to modify the exemption pursuant to 49 CFR Part 543.9(c)(2).

If General Motors does not implement the new antitheft device as described in your letter for MY 1992, we request that this agency be notified of such decisions.

Sincerely,

Barry Felrice Associate Administrator for Rulemaking / ref:Part 543 d:2/7/92

1992

ID: nht94-3.87

Open

TYPE: INTERPRETATION-NHTSA

DATE: August 5, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA; Stamped signature by Kenneth N. Weinstein

TO: William G. Franz -- Vice President Fabrication, Wells Aluminum Corporation

TITLE: NONE

ATTACHMT: Attached to letter dated 4/4/94 from William G. Franz to Walter Myers (OCC 9857)

TEXT: Dear Mr. Franz:

This responds to your letter addressed to Mr. Walter Myers of this office requesting an interpretation of window opening size as provided in paragraph S5.1.2, Federal Motor Vehicle Safety Standard (FMVSS) No. 217, Bus Emergency Exits and Window Retention and Release. I apologize for the delay in responding.

You explained that Wells Aluminum Corporation manufactures pushout windows for the school bus industry. You asked whether the 8-inch window opening size referred to in paragraph S5.1.2 applies to the "total outside frame dimension" or to each pane of gl ass. "In other words, would a pane of glass which measures less than 8 inches across need to be subject to the retention test [of S5.1 of FMVSS No. 217]?" To illustrate your question, you enclosed with your letter a picture of an upper/lower-pane pushou t window which was positioned for a retention test.

To be excluded from Standard No. 217's window retention requirement, the entire window, and not just a pane of the window, must be less than the 8-inch window opening size described in S5.1.2 of the standard. Section 5.1 of FMVSS No. 217 specifies reten tion requirements for windows other than windshields in buses. Paragraph S5.1.2 provides that those requirements do not apply to "a window whose minimum surface dimension measured through the center of its area is less than 8 inches." This exemption of 8 -inch windows was included in the standard in the final notice establishing the standard, published in the Federal Register on May 10, 1972 (37 FR 9394). In the preamble to that notice the agency stated at 37 FR 9395:

Since there is little likelihood of passenger ejection or protrusion from window openings whose minimum surface dimension measured through the center of the area is less than 8 inches, an exemption for windows of this size has been granted (emphasis adde d).

2

It is clear that the intent of the agency in providing this exemption was to exempt window openings, as measured by the perimeter of the window, not just individual panes of glazing material. A window can be composed of more than one pane of glazing mat erial, such as the window in the picture you provided, where 1 or more individual panes may have a minimum dimension smaller than 8 inches, but the whole window is larger than 8 inches. Regardless of the size of the individual panes which make up a wind ow, passenger ejection or protrusion could occur through such a window opening. Since ejection through such a window is precisely what the standard was intended to prevent, S5.1 would apply.

We note that you did not explain what you meant by "total outside frame dimension" and the meaning of the quoted phrase is not entirely clear. We assume you meant the entire window opening which, for the window in your picture, would include the combina tion of both panes and the window frame. Thus, for purposes of S5.1.2, we would measure both the pane and the window frame.

I hope this information is helpful to you. Should you have any further questions or need any further information, please feel free to contact Mr. Myers at this address or at (202) 366-2992.

ncc-20WMyers; mar:7/25/94:62992:OCC 9857 Ref:217 U: NCC20 INTERP 217 9857.WKM Greenbook: (2); Interps: Std. 217 Coord: NRM, NEF

ID: 9923

Open

Paul L. Anderson, President
Van-Con, Inc.
P.O. Box 237
123 William Street
Middlesex, NJ 08846-0237

Dear Mr. Anderson:

This responds to your letter of May 2, 1994, requesting information on which of the recent amendments to Standard No. 217, Bus Emergency Exits and Window Retention and Release (57 FR 49413; November 2, 1992, and 57 FR 57020; December 2, 1992), would apply to Type A-1 school buses. Your letter notes that Type A-1 school buses have a capacity of 16-20 passengers and a gross vehicle weight rating (GVWR) of less than 10,000 pounds.

The recent amendments to Standard No. 217 set new requirements for the provision of emergency exits based upon the seating capacity of the school bus (S5.2), set performance requirements for emergency exit window and emergency roof exit release (S5.3), revised the extension requirements for side doors and set extension requirements for emergency roof exits (S5.4), and revised the identification requirements (S5.5). The effect of each of these amendments on Type A-1 school buses is discussed separately below.

Provision of Emergency Exits (S5.2)

The recent amendments listed above revised S5.2.3 to specify the number and type of exits required on school buses, including Type A-1 school buses. This section states:

The area in square centimeters of the unobstructed openings for emergency exit shall collectively amount to at least 432 times the number of designated seating positions in the bus. The amount of emergency exit area credited to an emergency exit is based on the daylight opening of the exit opening.

The section also specifies the type of emergency exits which must be installed to meet this requirement. All school buses, including Type A-1 school buses, are required to have either a rear emergency exit door or a side emergency exit door and a rear push-out window. These are the same exits required by Standard

No. 217 before the recent amendments. After deducting the daylight opening of the front service door and the required exit(s), any remaining exit area must be provided by installing additional exits in the following order: (1) a side emergency exit door, (2) a emergency roof exit, and (3) any combination of emergency exit doors, emergency roof exits, and emergency exit windows.

Please note that, while these new requirements apply to all school buses, it is unlikely that a 20 passenger school bus will require additional exits. Under the new requirements, a school bus with 21 designated seating positions (20 passengers plus the driver) is required to provide 9,072 square centimeters of exit area. A school bus with a front service door and either of the mandatory options (rear emergency exit door or side emergency exit door and rear push-out window) should easily exceed this amount. To illustrate, in the past, the agency has estimated that the average front service door has a daylight opening of 12,916 square centimeters. For school buses with a GVWR of 10,000 pounds or less, a rear emergency door that is the minimum size required to meet the extension requirements has a daylight opening of 6,270 square centimeters. A side emergency door that is the minimum size required to meet the extension requirements has a daylight opening of 6,954 square centimeters. A rear push-out window that is the minimum size required has a daylight opening of 5,002 square centimeters.

Emergency Exit Release (S5.3)

The recent amendments added performance requirements for the release mechanisms for emergency exit windows and emergency roof exits on school buses. As explained above, the recent amendments should not require either of these types of exits to be installed on Type A-1 school buses. However, if either of these types of exits are voluntarily installed on Type A-1 school buses, the release mechanisms must comply with these requirements. In the recent amendments to Standard No. 217, some of the performance requirements, including the release requirements in S5.3, apply to "each" emergency exit. This language extends these requirements to any emergency exit door in a school bus, including voluntarily installed ones. Other requirements apply to "required" emergency exits. (See, for example, S5.5.3(c) discussed below.) Those requirements do not apply to voluntarily installed emergency exits.

Emergency Exit Extension (S5.4)

The amendments of the extension requirements also apply to Type A-1 school buses. The recent amendments revised the extension requirements for side doors on school buses with a GVWR of more than 4,536 kilograms (10,000 pounds) and set extension requirements for emergency roof exits on school buses with a GVWR of more than 4,536 kilograms (10,000 pounds). These amendments also affect school buses with a GVWR of 10,000 pounds or less, as the requirements specify that these vehicles are to comply with the same requirements as school buses with a GVWR of more than 10,000 pounds (except for the minimum size for rear emergency exit doors).

If a Type A-1 school bus has a side emergency exit door, that exit is required to comply with the amended requirements concerning access to the exit. Under the new requirements, side emergency exit doors are required to provide an opening at least 114 centimeters high and 61 centimeters wide. In addition, an aisle 30 centimeters wide (referenced to the rear edge of the door) must be provided from the longitudinal centerline of the bus to the exit. A seat bottom is allowed within this aisle if it flips up when not in use such that it no longer is within the aisle. Finally, no portion of a seat or restraining barrier may block access to the latch.

In addition, if an emergency roof exit is installed in a Type A-1 school bus, it is required to provide an opening at least 41 centimeters high and 41 centimeters wide under the new requirements.

Finally, all emergency exit doors, including emergency exit doors on Type A-1 school buses, are required to have a "positive door opening device" that, among other things, prevents the door from closing if it has been opened beyond a certain point (see, S5.4.2.1(a)(3)).

Emergency Exit Identification (S5.5)

Finally, the recent amendments revised the identification requirements (S5.5) for exits on all school buses, including Type A-1 school buses. As revised, each required emergency exit is required to be marked with the words "Emergency Door" or "Emergency Exit," as appropriate. For emergency exit doors, the location of this marking was not changed by these amendments. For emergency window exits and emergency roof exits, location requirements were added. In addition, each required emergency exit must be outlined with retroreflective tape. Please note however, that the identification requirements do not apply to voluntarily installed emergency exits (i.e., exits in excess of those required by S5.2.3).

You should be aware that there was a discrepancy concerning the size of the retroreflective tape caused by the metric conversion in the final rule. I have enclosed is a copy of a July 7, 1993 letter to Mr. Thomas D. Turner of the Blue Bird Body Company which discusses this issue. As explained in that letter, we plan to issue a correction notice of the November 2, 1992 rule that would specify a minimum size of 2.5 cm for the tape. Until the correction is issued, NHTSA will not take enforcement measures regarding tape size against a manufacturer who uses 1 inch wide retroreflective tape.

To summarize and answer your specific questions, Type A-1 school buses typically would not be affected by the recent amendment requiring either emergency roof exits or emergency window exits. However, required emergency exits (including a rear emergency exit door) are required to be outlined with retroreflective tape. In addition, all exits (required and voluntary) must comply with the new performance requirements for release and extension.

With respect to your receipt of an oral interpretation from agency staff, I would also like to emphasize that, to the extent there are questions concerning the meaning of any NHTSA standard or regulation, the only agency interpretations which are authoritative and which therefore can be relied upon by manufacturers are those issued in writing by the Chief Counsel. We have reminded agency staff not to make formal, or informal, oral statements that might be misinterpreted by manufacturers as official agency guidance on which they may safely rely.

Please note that recent delay of the effective date of the recent amendments applies only to provision of emergency exits (S5.2) (59 FR 22997; May 4, 1994). The other amendments were effective on May 2, 1994. I also note that the May 4 notice does not state "that it only applys (sic) to School Buses with capacity of 24 to 90 passengers." The notice does refer to tables in a previous NPRM which listed the types of exits required under the proposal for buses with a capacity in that range.

I have also enclosed a copy of the recent final rules for your use. I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992.

Sincerely,

John Womack Acting Chief Counsel

Enclosures

ref:217 d:5/18/94

1994

ID: nht94-3.1

Open

TYPE: INTERPRETATION-NHTSA

DATE: May 18, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Paul L. Anderson -- President, Van-Con, Inc.

TITLE: None

ATTACHMT: Attached To Letter Dated 5/2/94 From Paul Anderson To John Womack (OCC-9923)

TEXT: Dear Mr. Anderson:

This responds to your letter of May 2, 1994, requesting information on which of the recent amendments to Standard No. 217, Bus Emergency Exits and Window Retention and Release (57 FR 49413; November 2, 1992, and 57 FR 57020; December 2, 1992), would appl y to Type A-1 school buses. Your letter notes that Type A-1 school buses have a capacity of 16-20 passengers and a gross vehicle weight rating (GVWR) of less than 10,000 pounds.

The recent amendments to Standard No. 217 set new requirements for the provision of emergency exits based upon the seating capacity of the school bus (S5.2), set performance requirements for emergency exit window and emergency roof exit release (S5.3), r evised the extension requirements for side doors and set extension requirements for emergency roof exits (S5.4), and revised the identification requirements (S5.5). The effect of each of these amendments on Type A-1 school buses is discussed separately below.

Provision of Emergency Exits (S5.2)

The recent amendments listed above revised S5.2.3 to specify the number and type of exits required on school buses, including Type A-1 school buses. This section states:

The area in square centimeters of the unobstructed openings for emergency exit shall collectively amount to at least 432 times the number of designated seating positions in the bus. The amount of emergency exit area credited to an emergency exit is base d on the daylight opening of the exit opening.

The section also specifies the type of emergency exits which must be installed to meet this requirement. All school buses, including Type A-1 school buses, are required to have either a rear emergency exit door or a side emergency exit door and a rear p ush-out window. These are the same exits required by Standard

2

No. 217 before the recent amendments. After deducting the daylight opening of the front service door and the required exit(s), any remaining exit area must be provided by installing additional exits in the following order: (1) a side emergency exit door , (2) a emergency roof exit, and (3) any combination of emergency exit doors, emergency roof exits, and emergency exit windows.

Please note that, while these new requirements apply to all school buses, it is unlikely that a 20 passenger school bus will require additional exits. Under the new requirements, a school bus with 21 designated seating positions (20 passengers plus the driver) is required to provide 9,072 square centimeters of exit area. A school bus with a front service door and either of the mandatory options (rear emergency exit door or side emergency exit door and rear push-out window) should easily exceed this am ount. To illustrate, in the past, the agency has estimated that the average front service door has a daylight opening of 12,916 square centimeters. For school buses with a GVWR of 10,000 pounds or less, a rear emergency door that is the minimum size re quired to meet the extension requirements has a daylight opening of 6,270 square centimeters. A side emergency door that is the minimum size required to meet the extension requirements has a daylight opening of 6,954 square centimeters. A rear push-out window that is the minimum size required has a daylight opening of 5,002 square centimeters.

Emergency Exit Release (S5.3)

The recent amendments added performance requirements for the release mechanisms for emergency exit windows and emergency roof exits on school buses. As explained above, the recent amendments should not require either of these types of exits to be instal led on Type A-1 school buses. However, if either of these types of exits are voluntarily installed on Type A-1 school buses, the release mechanisms must comply with these requirements. In the recent amendments to Standard No. 217, some of the performan ce requirements, including the release requirements in S5.3, apply to "each" emergency exit. This language extends these requirements to any emergency exit door in a school bus, including voluntarily installed ones. Other requirements apply to "require d" emergency exits. (See, for example, S5.5.3(c) discussed below.) Those requirements do not apply to voluntarily installed emergency exits.

Emergency Exit Extension (S5.4)

The amendments of the extension requirements also apply to Type A-1 school buses. The recent amendments revised the extension requirements for side doors on school buses with a GVWR of more than 4,536 kilograms (10,000 pounds) and set extension requirem ents for emergency roof exits on school buses with a GVWR

3

of more than 4,536 kilograms (10,000 pounds). These amendments also affect school buses with a GVWR of 10,000 pounds or less, as the requirements specify that these vehicles are to comply with the same requirements as school buses with a GVWR of more th an 10,000 pounds (except for the minimum size for rear emergency exit doors).

If a Type A-1 school bus has a side emergency exit door, that exit is required to comply with the amended requirements concerning access to the exit. Under the new requirements, side emergency exit doors are required to provide an opening at least 114 c entimeters high and 61 centimeters wide. In addition, an aisle 30 centimeters wide (referenced to the rear edge of the door) must be provided from the longitudinal centerline of the bus to the exit. A seat bottom is allowed within this aisle if it flip s up when not in use such that it no longer is within the aisle. Finally, no portion of a seat or restraining barrier may block access to the latch.

In addition, if an emergency roof exit is installed in a Type A-1 school bus, it is required to provide an opening at least 41 centimeters high and 41 centimeters wide under the new requirements.

Finally, all emergency exit doors, including emergency exit doors on Type A-1 school buses, are required to have a positive door opening device.

Emergency Exit Identification (S5.5)

Finally, the recent amendments revised the identification requirements (S5.5) for exits on all school buses, including Type A-1 school buses. As revised, each required emergency exit is required to be marked with the words "Emergency Door" or "Emergency Exit," as appropriate. For emergency exit doors, the location of this marking was not changed by these amendments. For emergency window exits and emergency roof exits, location requirements were added. In addition, each required emergency exit must b e outlined with retroreflective tape. Please note however, that the identification requirements do not apply to voluntarily installed emergency exits (i.e., exits in excess of those required by S5.2.3).

You should be aware that there was a discrepancy concerning the size of the retroreflective tape caused by the metric conversion in the final rule. I have enclosed is a copy of a July 7, 1993 letter to Mr. Thomas D. Turner of the Blue Bird Body Company which discusses this issue. As explained in that letter, we plan to issue a correction notice of the November 2, 1992 rule that would specify a minimum size of 2.5 cm for the tape. Until the correction is issued, NHTSA will not take enforcement measure s

4

regarding tape size against a manufacturer who uses 1 inch wide retroreflective tape.

To summarize and answer your specific questions, Type A-1 school buses typically would not be affected by the recent amendment requiring either emergency roof exits or emergency window exits. However, required emergency exits (including a rear emergency exit door) are required to be outlined with retroreflective tape. In addition, all exits (required and voluntary) must comply with the new performance requirements for release and extension.

With respect to your receipt of an oral interpretation from agency staff, I would also like to emphasize that, to the extent there are questions concerning the meaning of any NHTSA standard or regulation, the only agency interpretations which are authori tative and which therefore can be relied upon by manufacturers are those issued in writing by the Chief Counsel. We have reminded agency staff not to make formal, or informal, oral statements that might be misinterpreted by manufacturers as official age ncy guidance on which they may safely rely.

Please note that recent delay of the effective date of the recent amendments applies only to provision of emergency exits (S5.2) (59 FR 22997; May 4, 1994). The other amendments were effective on May 2, 1994. I also note that the May 4 notice does not s tate "that it only applys (sic) to School Buses with capacity of 24 to 90 passengers." The notice does refer to tables in a previous NPRM which listed the types of exits required under the proposal for buses with a capacity in that range.

I have also enclosed a copy of the recent final rules for your use. 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,

Enclosures

ID: nht75-4.40

Open

DATE: 06/03/75

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

TO: Blue Bird Body Company

TITLE: FMVSS INTERPRETATION

TEXT: This is in response to your letter of May 19, 1975, inquiring as to the effect of Federal Motor Vehicle Safety Standard No. 217, Bus Window Retention and Release, on a Connecticut law relating to school bus window emergency release.

As you are aware, section 103(d) of the National Traffic and Motor Vehicle Safety Act of 1966 (15 U.S.C. 1392(d)) provides that no State or political subdivision of a State may promulgate or continue in effect standards applicable to an aspect of motor vehicle or motor vehicle equipment performance which is covered by a Federal motor vehicle safety standard, unless the standards are identical.

Standard No. 217 includes provisions relating to emergency exit force applications. A differing State specification for emergency release force applications is voided by @ 103(d) since the Federal standard is intended to cover all aspects of emergency window release performance.

As explained in our November 29, 1974, letter to Mr. Donald L. Gibson (copy enclosed) a Federal standard will preempt any State law that relates to the same aspect of motor vehicle performance yet imposes different requirements.

Your responsibility as a manufacturer is to comply with the Federal safety standard. You should note, however, that purchase specifications may be imposed by any person or organization, including a State or municipality, with respect to vehicles purchased for the person or organization's own use. Such specifications are not limited by Federal law, and in the case of governmental bodies are specifically allowed by S 103(d), although of course they cannot alter a manufacturer's duty to conform to Federal standards.

SINCERELY,

May 19, 1975

Richard Dyson Assistant Chief Counsel U. S. Department of Transportation NHTSA

The State of Connecticut recently adopted new school bus specifications which will become effective on school buses manufactured after January 1, 1976. In two areas these specifications are more restrictive than FMVSS 217 Bus Window Retention and Release.

In section 14-275B-16 (d) and 14-275B-17 (a), (see attached copies), the Connecticut specifications call for emergency exit release forces of between 5 and 15 pounds and 5 and 20 pounds respectively. Since these forces are different than those required by FMVSS 217, this imposes an additional constraint on school bus manufacturers for that state. Also, we are concerned that latch forces as low as 5 pounds could result in inadvertent opening of emergency exits.

We are in receipt of a copy of a letter which you sent to Mr. Donald L. Gibson, dated November 27, 1974, with file reference N40-30 (KK). In that letter you state:

"The federal requirements must be regarded as conclusive with regard to parking brake performance and emergency braking capability in order to maintain the uniformity necessary in a federal regulatory scheme. If states were permitted to impose additional requirements in an area regulated by a federal safety standard, manufacturers would be confronted with an impossible task of compliance. This reasoning formed the bais of the recent decision rendered in a case brought by the Motorcycle Industry Council, Inc., against the State of California in the United States District Court for the Eastern District of California concerning the preemption of a California State requirement that motorcycle lamps be wired to operate when the engine is running. The court held that the California requirement is preempted by the Federal Motor Vehicle Standard 108 since the NHTSA intended to cover all aspects of performance directly involving motorcycle headlamps."

It appears to us that this current conflict between the new Connecticut regulations and FMVSS 217 is similar to the matter which you addressed in your letter quoted above.

In the light of such conflicting specifications, what is our responsibility as a school bus manufacturer.

W. G. Milby Staff Engineer

CC: JOHN O'CONNELL; DAVE PHELPS

MINIMUM REQUIREMENTS FOR TYPE I SCHOOL BUS CONSTRUCTION AND EQUIPMENT the release mechansism should be turned to open the emergency door shall be painted on the outside of the emergency door in black on the national school bus yellow background. The emergency door shall have a horizontal opening of at least 30 inches and a vertical opening of at least 48 inches measured from the floor level. No steps shall lead to the emergency door. The emergency door or exit shall be devised so as to be opened from the inside and the outside.

(b) The passage to the emergency door shall be kept clear of obstructions. For rear doors the horizontal clearance of 30 inches shall be maintained for a distance of at least twelve inches inside the bus. When the emergency door is in the left side, a minimum horizontal clearance of 30 inches and a vertical clearance of 48 inches shall be maintained between it and the center aisle.

(c) The upper and lower portion of the central rear emergency door shall be equipped with approved safety glass, the exposed area of which shall be not less than four hundred (400) square inches in the upper portion and not less than three hundred (300) square inches in the lower portion. The left side emergency door shall be equipped with safety glass in the upper portion and the lower portion shall be of at least the same gauge metal as the body outer panels. The emergency door shall be hinged on the right side if it is in the rear end of the bus and on the front side if it is in the left side and shall open only outward. Control from the driver's seat shall not be permitted.

(d) The emergency door shall be equipped with a slide-bar, cam-operated latch which shall have a minimum stroke of one inch. The latch shall be equipped with a suitable electric plunger-type switch connected with a distinctive audible signal automatically operated and located in the driver's compartment which shall clearly indicate the unlatching of this door and no cutoff switch shall be installed in the circuit. The switch shall be enclosed in a metal case, and wires leading from the switch shall be concealed in the body. The switch shall be so installed that the plunger contacts the farthest edge of the slide bar in such a manner that any movement of the slide bar will immediately close the circuit and activate the signal. The door latch shall be equipped with an interior handle which shall be capable of quick release upon application of a force between 5 and 15 pounds but shall be protected agains accidental release. It shall lift up to release the latch. The outside handle shall be installed in a vertical position when latched so as to minimize hitching and shall be a non-detachable device.

(e) An audio alarm shall indicate to the driver when any door is in the locked position while the ignition switch is in the "on" position.

Sec. 14-275b-17. Emergency Windows. (a) A rear emergency window at least 16 inches in height and as wide as practicable shall be provided in any bus where the emergency door is not in the rear. The rear window shall be designed so as to be opened from either the inside or the outside. It shall be hinged at the top and be equipped with a linkage or mechanism that will automatically hold the opened window against the force of gravity at a hinge opening angle of 60 +/- 5 degrees measured from the closed window position. Such linkage or mechanism shall not prevent the window from opening a full 90 degrees due to gravitational forces should the bus be inverted. A positive latch on the inside shall provide for quick release upon application of a force between 5 and 20 pounds but offer protection against accidental release. The outside handle shall be non-detachable and designed to minimize hitching.

(b) Labeling shall indicate in 1/2 inch letters on the inside how the window operates and in letters at least two inches in height the words "Emergency Exit" above on the inside and directly below on the outside.

(c) A distinctive audible signal automatically operated shall clearly indicate to the driver the unlatching of the rear emergency window or the opening of any push-out emergency windows and no cutoff switch shall be installed in the circuit.

(d) If there is a space between the top of the rear divan seat and the inside lower edge of the rear emergency window, such space shall be covered by a material of sufficient strength to sustain 600 pounds weight.

Sec. 14-275b-18. Exhaust System and Muffler. The exhaust system shall include the exhaust manifold and gaskets, piping leading from the flange of the exhaust manifold to and including the muffler(s). The system shall not extend into the body and shall be attached to the chassis. The tail pipe(s) shall be non-flexible sixteen gauge steel or equivalent and shall extend beyond the rear end of the chassis frame but not beyond the rear limit of the bumper. The complete exhaust system shall be tight and free from leaks and shall be properly insulated from the electrical wiring or any combustible part of the bus. It shall not pass within twelve inches of the fuel tank or its connections except that the exhaust system may come within four inches of the fuel tank or its connections if a suitable heat baffle is installed between the exhaust system and such tank or connections. The size of the pipes in the exhaust system shall not be reduced below that at the engine manifold.

$99(Illegible word)

1-28-75

ID: nht76-2.36

Open

DATE: 11/22/76

FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA

TO: TYM Industries Co., Ltd.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of September 27, 1976, to the National Highway Traffic Safety Administration, concerning lighting requirements for mopeds.

The headlamp must be designed to conform to SAE Standard J584, "Motorcycle and Motor Driven Cycle Headlamps," April 1964. This Standard does not require a sealed beam headlamp, nor is a minimum wattage specified. Obtaining an AAMVA certificate is probably the best way of insuring that a State raises no obstacles to registry of your vehicle.

There is no minimum wattage for the taillamp or stop lamp. These two lamps may be combined. There is no Federal requirement for SAE identification; however, most lamps are so identified, because of the requirements in the state of Virginia.

ID: nht79-4.23

Open

DATE: 10/22/79

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: Uniroyal GmbH

TITLE: FMVSR INTERPRETATION

TEXT: This is in response to your letter of October 12, 1979, asking whether the character height of 5/32nds of an inch, stated in the Uniform Tire Quality Grading (UTQG) Standards (49 CFR 575.104, Figure 1), is considered by the National Highway Traffic Safety Administration (NHTSA) to specify the only acceptable height for UTQG sidewall molding, or whether the agency interprets this measurement as a minimum value.

The specification of 5/32nds of an inch tire sidewall characters was intended by NHTSA to establish a minimum requirement to assure readability of the UTQG information presented. The agency has no objection to the use of characters of a height greater than 5/32nds of an inch, so long as all characters used to convey UTQG information are of the same height.

ID: nht91-6.4

Open

DATE: September 18, 1991

FROM: Robert A. Nordmeyer -- Nordic Associates

TO: NHTSA Administrator, Rule Making Department

TITLE: None

ATTACHMT: Attached to letter dated 11-13-91 from Paul Jackson Rice to Robert A. Nordmeyer (A38; Std. 201; Std. 302)

TEXT:

We are developing an after market sun visor for a client (illustrations attached).

Would you please advise me if there are any federal sanctions governing the design, maximum viewing area that may be blocked by such a device, minimum force required to secure the visor in the extended or retracted position and minimum amount of padding on edges of the visor.

If you have any questions regarding this issue, I can be reached by phone at (818) 347-1597 or Fax (818) 883-3342.

ATTACHMENT

Six drawings of sun visors. (Graphics omitted)

ID: aiam5432

Open
Mr. Thomas D. Turner Manager, Engineering Services Blue Bird Body Company P.O. Box 937 Fort Valley, GA 31030; Mr. Thomas D. Turner Manager
Engineering Services Blue Bird Body Company P.O. Box 937 Fort Valley
GA 31030;

"Dear Mr. Turner: This responds to your letter of May 2, 1994 requesting an interpretation of how the term 'daylight opening,' as used in a recent amendment of Standard No. 217, Bus Emergency Exits and Window Retention and Release, would apply to various exits (57 FR 49413, November 2, 1992, and 57 FR 57020, December 2, 1992). Your letter references a March 24, 1994 interpretation letter to Mr. Bob Carver of Wayne Wheeled Vehicles. That letter discussed the term 'daylight opening' as follows: The term 'daylight opening' is defined in the Final Rule as 'the maximum unobstructed opening of an emergency exit when viewed from a direction perpendicular to the plane of the opening.' An obstruction in this context would include any obstacle or object that would block, obscure, or interfere with, in any way, access to that exit when opened. In determining the 'maximum unobstructed opening of an emergency exit,' we would subtract, from the total area of the opening, the area of any portions of the opening that cannot be used for exit purposes as a result of the obstruction. The area measurements would be taken when viewed from a direction perpendicular to the plane of the opening. Your letter states that this interpretation represents a drastic change in what we understood from the wording of the final rule ... and what we were told by Rulemaking. We believed and were told that the definition of daylight opening applied to the exit opening itself and did not involve access to the opening. Access to and obstruction of openings are addressed later in the standard in section S5.4.2 School Bus Emergency Exit Extension. Before answering your specific questions, I would like to respond to these statements. You are correct that S5.4.2 includes requirements related to access to, and obstruction of, exits in that it specifies the minimum opening and the minimum amount of access required for various exits. However, the issue of minimum opening is separate from the issue, addressed in S5.2.3, of the maximum amount of area credited for any opening. Section S5.2.3 specifies the number and type of exits required on school buses. This section states: The area in square centimeters of the unobstructed openings for emergency exit shall collectively amount to at least 432 times the number of designated seating positions in the bus. The amount of emergency exit area credited to an emergency exit is based on the daylight opening of the exit opening. Thus, S5.2.3 specifies the maximum amount of area credited for any opening. An interpretation of the term 'daylight opening' that allowed credit for the exit opening, regardless of obstructions, would be contrary to the plain language of the definition of that term. Giving credit for obstructed areas would also be contrary to the intent of the final rule, which is to increase the area on larger buses which is available for exit in an emergency. With respect to your report of receiving an oral interpretation from agency staff, I would also like to emphasize that, to the extent the public has any questions concerning the meaning of any NHTSA standard or regulation, the only agency interpretations which are authoritative and which therefore can be relied upon by members of the public, such as manufacturers, are those issued in writing by the Chief Counsel. We have reminded agency staff not to make formal, or informal, oral statements that might misinterpreted by manufacturers as official agency guidance on which they may safely rely. Your letter states that the March 24 interpretation 'raises other questions regarding the various school bus emergency exits.' Your questions and the response to each follows. By way of background information, NHTSA does not approve motor vehicles or motor vehicle equipment. The following represents our opinion based on the facts provided in your letter. Rear Emergency Exit Door a. Section S5.4.2.1(a)(1) ... requires unobstructed passage of a rectangular parallelepiped 30 centimeters deep. It is our rationale and interpretation that a seat back or other interior component that lies forward of this 30 centimeter deep parallelepiped is not an obstruction to the rear emergency door and would not result in a reduction of the area credited to the rear emergency door. (See figure 1a) Is this interpretation correct? In the case of a rear emergency exit door, the depth requirement in S5.4.2.1(a)(1) reflects a determination that an interior component outside that limit does not render the exit unusable. Therefore, an interior component outside the area bounded by the transverse vertical plane of the exit opening, the two longitudinal vertical planes tangent to the sides of the exit opening, and the transverse vertical plane parallel to and 30 centimeters away from the plane of the exit opening would not be considered an obstruction for determining the area of 'daylight opening.' b. School buses are typically equipped with 39-inch (99 cm) wide seats. At the rear emergency door, one of the rear seats is typically shifted forward to provide the clearance required by S5.4.2.1(a)(1). The other rear seat is typically allowed to be near or against the rear wall of the bus to fully utilize the available seating floor space and to provide maximum knee clearance. When viewed from the rear, this seat protrudes into the door opening, and according to the (March 24) interpretation ..., the area of the obstruction would not be credited to the exit. Following the logic of the interpretation, the area of the seat itself and the area above the seat could not be credited. We disagree with the logic of the interpretation that door exits are only used by movement along the floor. If the bus is on its side or top, the exit must be used from different approaches. It is therefore our logic and interpretation that only the actual area obstructed (i.e. the area of the seat and the area below the seat) cannot be credited to the exit. For the case in question, the area above the seat can be used in many accident scenarios and therefore can be credited as 'daylight opening.' (See figure 1b) Is this interpretation correct? You are correct that emergency doors will be used by people moving along an interior surface other than the floor if the vehicle is on its side or roof following an accident. As stated in the March 24 interpretation, in determining the amount of daylight opening, you should not credit any area which 'cannot be used for exit purposes.' In the case of the seat illustrated in incoming letter from Wayne, the area over the seat is 6.12 inches by 12.5 inches. However, in reviewing that letter in light of your question, we now agree that the area over the seat may be usable in some accident scenarios. For your exit, neither your letter nor figure 1b provide dimensions of the area over the seat. If the area is large enough to be usable in an accident scenario, that area can be credited towards the daylight opening. c. The rear emergency door on Blue Bird school buses is hinged on the outside, and the top portion of the door is angled forward when the door is closed. When the door is opened and held in the open position by the device required by S5.4.2.1(a)(3)(i), the door protrudes into the exit opening when viewed from a direction perpendicular to the plane of the opening. It is our understanding, based on the interpretation of reference 3, that the protrusion of the door now constitutes an obstruction and the area of the obstruction cannot be credited to the exit area. (See figure 1c) Is this understanding correct? This is correct. Emergency Window Exits The seat backs of school bus seats can protrude into the lower region of side window exit openings. Side window exits when the bus is upright may be used by climbing over the seats. If the bus is on its side or top, the side window exits may be used from different approaches. Since areas of sufficient size above, in front of, and behind a protruding seat back could be used for different parts of the body, (i.e. head, knees, legs) when crawling out a side window exit in different vehicle orientations, it is our logic and interpretation that only the actual area of the seat back in the side window exit opening and the smallest area bounded by the seat back, a horizontal plane tangent to the top of the seat back, and the edges of the exit opening constitute obstructions and cannot be credited to the exit. (See figure 2) Is this interpretation correct? In your illustrations, the area obstructed by the seat back protruding into the window opening clearly cannot be credited to the daylight opening. Whether area above or forward or rearward of the seat back can be credited depends on whether the size of the area is sufficient to be used in exiting the vehicle. Any of these areas which permits passage of the ellipsoid proposed in a December 1, 1993 notice of proposed rulemaking indicates that these areas clearly should be credited (58 FR 63321, see proposed S5.4.2.1(c)). NHTSA proposed this because it believed it reflected the minimum size window which could be used as an exit. If not cut off by obstructions from other unobstructed areas of the daylight opening of the window, as viewed in a plan view, it may be possible that smaller areas should also be credited. In all of the illustrations in figure 2, the seat back extends less than halfway up in the opening. Therefore, it appears that the area above the seat would be credited. We also agree that if the seat protrudes near the front or rear edge of the window opening, it is unlikely that the area between the seat back and the nearest edge of the opening would be usable. However, one of your illustrations shows the seat back protruding near the center of the window opening. In such an instance, it may be possible that the area on each side of the seat back is large enough to be usable. For example, a person might use the window by climbing over the seat, with either their legs straddling the seat, or their head and torso over one side of the seat and their legs over the other. Side Emergency Exit Doors Following the logic presented above regarding the use of emergency exits in different vehicle orientations, we disagree with the interpretation that area A2 (an area bounded by a horizontal line tangent to the top of the seat back, a vertical line tangent to the rearmost portion of the top of the seat, the upper edge of the door opening, and the edge of the door forward of the seat) ... is not usable. In fact even when using the side emergency door when the vehicle is upright, a person would likely lean over the seat back and hold on to the seat, thus using area A2. Figure 3 enclosed is drawn more to scale than the illustration used in (the March 24 interpretation). We suggest the Agency review this illustration, conduct field research by using the exits in real buses, and then reconsider the interpretation ... regarding side emergency doors. We recommend that area A2 be credited as 'daylight opening' for a side emergency door. As explained in our response to question b on rear emergency exit doors, the area above some seats may be large enough to be credited toward the daylight opening. Front Service Door a. The lower portion of the grab handle on many school bus front service doors protrudes into the exit opening when viewed from a direction perpendicular to the plane of the opening. (See figure 4) Based on the (March 24) interpretation ..., we understand that this protrusion now constitutes an obstruction. Is this understanding correct? This is correct. b. The front service door of most school buses leads to a stepwell and steps used to enter the bus. On front engine transit style school buses, the steps are typically angled to the rear and the riser to the first step is just a few inches inboard of the door opening. It is our logic and interpretation that steps in a stepwell do not constitute an obstruction and their presence does not reduce the area credited to the entrance door opening. (See figure 4) Is this interpretation correct? The steps provide the means of using the door, allowing a person to move between the ground and the floor level of the bus. They do not 'block, obscure, or interfere with, in any way, access' of occupants descending to the front service door. Therefore, although they are visible in the doorway when the doorway is viewed in a plan view, the steps are not obstructions within the meaning of the definition of daylight opening. I hope you find this information helpful. If you have any other questions, please contact my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel";

ID: 10878

Open

Mr. Musa K. Farmand
Gonz555-B Blanding Boulevard
Orange Park, FL 32073

Dear Mr. Farmand:

This responds to your letter of April 27, 1995. Your letter concerns a law suit in which you represent plaintiffs injured in an automobile accident. In this law suit, the counsel for the defendant has moved to amend his answer to assert that 49 CFR 571.208, paragraph S4.1.5.2(c)(2) requires each state to allow for mitigation of damages in any seat belt use law and that paragraph preempts the Florida mandatory seat belt law. According to your letter, the Florida law "does not allow a mitigation of damages defense with respect to an alleged failure to wear a seat belt." As explained below, the National Highway Traffic Safety Administration agrees with you that the Florida safety belt use law is neither expressly nor impliedly preempted by Federal law.

Purpose of Paragraph S4.1.5.2(c)(2)

Before discussing the issue of preemption, I want to discuss the background and purpose of Paragraph S4.1.5.2(c)(2). That paragraph was added to Standard No. 208, Occupant Crash Protection (49 CFR 571.208) as part of a final rule issued July 17, 1984 concerning automatic restraints (49 FR 28962). That final rule required all new cars to have automatic protection (air bags or automatic belts) starting in the 1990 model year. The final rule included a provision that the automatic restraint requirement would be rescinded if the Secretary of Transportation determined, not later than April 1, 1989, that a sufficient number of States had enacted belt use laws meeting certain minimum criteria to cover at least two-thirds of the U.S. population (paragraph S4.1.5). Under S4.1.5, the Secretary was not required to make any determination about any State safety belt laws. In fact, the Secretary never did so, in part because not enough States adopted mandatory seat belt use laws of any

sort prior to April 1, 1989. Because no determination was made under S4.1.5, the automatic restraint requirements are now in effect for all passenger cars.

The minimum criteria were set forth in S4.1.5.2 of Standard No. 208 . One of the criteria was "a provision specifying that the violation of the belt usage requirement may be used to mitigate damages..." (S4.1.5.2(c)(2)). However, S4.1.5 neither purported to require nor was intended to require States to enact safety belt use laws. In addition, S4.1.5 did not require that any State safety belt use laws had to incorporate the minimum criteria of S4.1.5.2. Paragraph S4.1.5 merely provided that the Secretary would rescind the automatic restraint requirement if he or she determined that a sufficient number of States enacted laws which met the criteria of S4.1.5.2 by April 1, 1989.

Preemption

The Florida safety belt use law is not and never has been either expressly or impliedly preempted by Federal law.

Standard No. 208 was issued under 49 U.S.C. Chapter 301 which expressly preempts state laws only to the extent provided by section 30103. That section provides for the express preemption of State motor vehicle safety standards that are not identical to Federal standards. However, the Florida seat belt law is not a motor vehicle safety standard within the meaning of Chapter 301, since it does not regulate motor vehicle or motor vehicle equipment performance. Accordingly, the Florida law is not expressly preempted.

The Florida law is not impliedly preempted because (1) Congress has not occupied the field of regulation of the behavior of motor vehicle occupants; and (2) the Florida seat belt law does not conflict with any Federal law or interfere with the objectives of Federal law.

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

Sincerely,

John Womack Acting Chief Counsel

ref:208 d:5/9/95 Your letter correctly notes that this provision was deleted from Standard No. 208 by a final rule issued on September 2, 1993 (58 FR 46551).

1995

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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