Interpretation ID: nht94-5.22

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 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

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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

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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.

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

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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,

Enclosures