Manager, Engineering Services
Blue Bird Body Company
P.O. Box 937
Fort Valley, Georgia 31030
Dear Mr. Turner:
This responds to your September 20, 1995, letter asking three questions about school bus requirements in Federal Motor Vehicle Safety Standard (FMVSS) No. 217, Bus emergency exits and window retention and release.
Your first question is whether, under NHTSA's May 9, 1995, final rule amending FMVSS No. 217, a left side exit door would have to meet the emergency exit location requirements if there were also two exit windows that by themselves satisfy the additional exit requirement of Table 1. The answer is no. Table 1 requires buses with a seating capacity of 46 or larger to have as additional emergency exits "1 left side exit door or two exit windows" (emphasis added). The word "or" indicates that either is sufficient. Therefore, if both a door and two exit windows are provided, the manufacturer could designate either as satisfying the requirements, and the other would not be required to meet the location requirement. Section S18.104.22.168(a)(2)'s location requirement is explicitly limited in scope to only "the first side emergency exit door installed pursuant to Table 1." (emphasis added). Additional exit doors beyond those required would not be considered to be installed pursuant to Table 1.
Standard No. 217 formerly contained a provision requiring that emergency exits installed in addition to what is required for school buses have to meet the requirements for emergency exits from non-school buses. This requirement was dropped from the standard on January 27, 1976 (41 FR 3871). We note, however, that in an emergency, the extra emergency exit could be the exit
of choice by some occupants. To avoid confusion, the force and motion needed to open the exit should be consistent with the other emergency exits.
Further, the voluntarily installed side exit doors would still be subject to prohibitions and requirements that apply to side exit doors generally. For example, S22.214.171.124(a)(4) prohibits installing two side exit doors "in whole or in part, within the same post and roof bow panel space." In addition, section S126.96.36.199(a)(1) requires "each" side exit door to be hinged on its forward side (not merely those doors installed pursuant to Table 1).
If windows are used to comply with the additional emergency exit requirements of Table 1, they should be located in the same place as the emergency exit door would have been, "as near as practical to the mid-point of the passenger compartment." See the attached August 4, 1995, interpretation letter that NHTSA sent to Thomas Built Buses on this subject.
Your second question concerns the language in S188.8.131.52(c) of the same final rule stating that "[s]chool buses shall not be equipped with horizontally-sliding emergency exit windows." Blue Bird sells some buses with windows that have sections that slide horizontally to provide ventilation, but also push out to create an emergency exit opening. You were concerned that the literal language of the final rule would prohibit these windows because they are emergency exit windows and they slide horizontally. Instead, your understanding is that the language "horizontally-sliding emergency exit windows" was intended to mean "windows that create the exit opening by sliding horizontally."
Your understanding is correct, because NHTSA does not prohibit horizontally-sliding windows generally. There are no safety concerns about horizontally-sliding emergency exit windows that do not apply to other windows in the school bus, unless the window is opened horizontally to its wider, emergency exit-size opening.
Your third question concerns the requirement in the May 9, 1995, final rule that "[i]n the case of windows with one release mechanism, the mechanism shall require two force applications to release the exit." This language first appeared in a November 2, 1992, final rule. NHTSA acknowledged in a June 13, 1994, interpretation letter that the language was incorrect and should have read "[i]n the case of windows with one release mechanism, the exit shall require two force applications to open." (emphasis added). The June 13 interpretation stated NHTSA's intention not to enforce the rule so long as the exit requires two force applications to open, and to issue a correction notice in the future. The language was unfortunately repeated in the May 9, 1995, final rule, but the June 13 interpretation still reflects the agency's position.
I hope this information is helpful. If you have any further questions, feel free to contact Paul Atelsek of my staff at 202-366-5260.
Samuel J. Dubbin Chief Counsel ref:217 d:3/20/96