Rod Nash, V.P. Engineering
Collins Industries, Inc.
15 Compound Drive
Hutchinson, KS 67502-4349
Dear Mr. Nash:
This responds to your May 30, 2002, letter asking about an April 19, 2002, final rule that amended Federal Motor Vehicle Safety Standard (FMVSS) No. 217, Bus emergency exits and window retention and release (67 FR 19343). The rule restricted where wheelchair securement anchorages may be installed, to ensure that they do not block access to emergency exit doors. You ask whether the rules restrictions limit or supercede requirements in S5.4.2 of the standard, which requires unobstructed passage of a parallelpiped through the emergency exit door. The answer is no.
Your first question concerned the meaning of S220.127.116.11, which states:
S18.104.22.168 Except as provided in paragraph S22.214.171.124 [for tracks and track-type devices running on the school bus floor] of this section, no portion of a wheelchair securement anchorage shall be located in a school bus such that:
(a) In the case of side emergency exit doors, any portion of the wheelchair securement anchorage is within the space bounded by the interior side wall and emergency exit door opening, transverse vertical planes 305 mm (12 inches) forward and rearward of the center of any side emergency exit door restricted area, and a longitudinal vertical plane through the longitudinal centerline of the school bus, as shown in Figure 6A and Figure 6B.
(b) In the case of rear emergency exit doors in school buses with a gross vehicle weight rating greater than 4,536 kg (10,000 lb), any portion of the wheelchair securement anchorage is within the space bounded by longitudinal vertical planes tangent to the left and right sides of the door opening, a transverse vertical plane 305 mm (12 inches) forward of the bottom edge of the door opening, and a horizontal plane 1,145 mm (45 inches) above the floor of the bus, as shown in Figure 6C and Figure 6D.
(c) In the case of rear emergency exit doors in school buses with a gross vehicle weight rating of 4,536 kg (10,000 lb) or less, any portion of the wheelchair securement anchorage is within the space bounded by longitudinal vertical planes tangent to the left and right sides of the door opening, a transverse vertical plane 150 mm (6 inches) forward of the bottom edge of the door opening, and a horizontal plane 1,145 mm (45 inches) above the floor of the bus, as shown in Figure 6C and Figure 6D.
You ask whether S126.96.36.199 means that "the exit space in front of the rear emergency exit door of a school bus is now determined by the width of that door." The answer is no. The requirements of S188.8.131.52 are separate from the requirements in S5.4.2 for minimum exit aisle space to the rear emergency exit door. The latter requirement was established in a 1976 final rule (41 FR 3871, January 27, 1976). Today, the requirement is specified at S184.108.40.206, for school buses with a gross vehicle weight rating (GVWR) of more than 10,000 pounds. S220.127.116.11 requires that an opening large enough to permit unobstructed passage of a rectangular parallelepiped 1145 mm x 610 mm x 305 mm (45 inches x 24 inches x 12 inches) to the rear emergency exit door be provided, keeping the parallelepiped upright and the lower surface in contact with the floor of the bus at all times. S18.104.22.168 specifies the same requirements for school buses with a GVWR of 10,000 pounds or less, except that the parallelepiped is 1145 mm x 550 mm x 150 mm (45 inches x 22 inches x 6 inches). S5.4.2 remains in effect today, and still requires exits on large and small school buses to be, basically, 24 and 22 inches wide, respectively, and to provide adequate emergency aisle space.
The new requirements in S22.214.171.124 set forth dimensions in which wheelchair securement anchorages may not be installed. This prohibition is intended to minimize the chances that a wheelchair would be installed in a school bus in service at a position where the emergency exit would be blocked or obstructed by the wheelchair. This complements the minimum dimensional requirements for exits.
I hope this information is helpful. If you have any further questions, please contact Dorothy Nakama of my staff at this address or at (202) 366-2992.
 Parallelepipeds were also proposed for S5.4.3 but were not included in the final rule. The final rule stated: "NHTSA has determined that defining the space by using planes better meets NHTSAs intention in restricting spaces where the wheel chair securement may not be placed [than specifying a parallelepiped], as the space defined by planes would explicitly include the floor near the school bus rear emergency exit door." (See 67 FR at 19346.)