[Code of Federal Regulations]
[Title 49, Volume 5]
[Revised as of October 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR571.217]

[Page 636-658]
 
                        TITLE 49--TRANSPORTATION
 
                            OF TRANSPORTATION
 
PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS--Table of Contents
 
            Subpart B--Federal Motor Vehicle Safety Standards
 
Sec. 571.217  Standard No. 217; Bus emergency exits and window retention and release.

    S1. Scope. This standard establishes requirements for the retention 
of windows other than windshields in buses, and establishes operating 
forces, opening dimensions, and markings for bus emergency exits.
    S2. Purpose. The purpose of this standard is to minimize the 
likelihood of occupants being thrown from the bus and to provide a means 
of readily accessible emergency egress.
    S3. Application. This standard applies to buses, except buses 
manufactured for the purpose of transporting persons under physical 
restraint.
    S4. Definitions. Adjacent seat means a designated seating position 
located so that some portion of its occupant space is not more than 10 
inches from an emergency exit, for a distance of at least 15 inches 
measured horizontally and parallel to the exit.
    Daylight opening means the maximum unobstructed opening of an 
emergency exit when viewed from a direction perpendicular to the plane 
of the opening.
    Mid-point of the passenger compartment means any point on a vertical 
transverse plane bisecting the vehicle longitudinal centerline that 
extends between the two vertical transverse planes which define the 
foremost and rearmost limits of the passenger compartment.
    Occupant space means the space directly above the seat and footwell, 
bounded vertically by the ceiling and horizontally by the normally 
positioned seat back and the nearest obstruction of occupant motion in 
the direction the seat faces.
    Passenger compartment means space within the school bus interior 
that is between a vertical transverse plane located 76 centimeters in 
front of the forwardmost passenger seating reference point and a 
vertical transverse plane tangent to the rear interior wall of the bus 
at the vehicle centerline.
    Post and roof bow panel space means the area between two adjacent 
post and roof bows.
    Push-out window means a vehicle window designed to open outward to 
provide for emergency egress.

[[Page 637]]

    Sliding window means a bus window designed to open by moving 
vertically or horizontally to provide emergency egress.
    S5. Requirements.
    S5.1  Window retention. Except as provided in S5.1.2, each piece of 
window glazing and each surrounding window frame when tested in 
accordance with the procedure in S5.1.1 under the conditions of S6.1 
through S6.3, shall be retained by its surrounding structure in a manner 
that prevents the formation of any opening large enough to admit the 
passage of a 4-inch diameter sphere under a force, including the weight 
of the sphere, of 5 pounds until any one of the following events occurs:
    (a) A force of 1,200 pounds is reached.
    (b) At least 80 percent of the glazing thickness has developed 
cracks running from the load contact region to the periphery at two or 
more points, or shattering of the glazing occurs.
    (c) The inner surface of the glazing at the center of force 
application has moved relative to the window frame, along a line 
perpendicular to the undisturbed inner surface, a distance equal to one-
half of the square root of the minimum surface dimension measured 
through the center of the area of the entire sheet of window glazing.
    S5.1.1  An increasing force shall be applied to the window glazing 
through the head form specified in Figure 4, outward and perpendicular 
to the undisturbed inside surface at the center of the area of each 
sheet of window glazing, with a head form travel of 2 inches per minute.
    S5.1.2  The requirements of this standard do not apply to a window 
whose minimum surface dimension measured through the center of its area 
is less than 8 inches.
    S5.2  Provision of emergency exits.
    S5.2.1  Buses other than school buses shall meet the requirements of 
either S5.2.2 or S5.2.3. School buses shall meet the requirements of 
S5.2.3.
    S5.2.1.1  A bus with GVWR of more than 10,000 pounds may satisfy the 
unobstructed openings requirement by providing at least one side door 
for each three passenger seating positions in the vehicle.
    S5.2.2  Buses other than school buses.
    S5.2.2.1  Buses other than school buses shall provide unobstructed 
openings for emergency exit which collectively amount, in total square 
centimeters, to at least 432 times the number of designated seating 
positions on the bus. At least 40 percent of the total required area of 
unobstructed openings, computed in the above manner, shall be provided 
on each side of a bus. However, in determining the total unobstructed 
openings provided by a bus, no emergency exit, regardless of its area, 
shall be credited with more than 3,458 square centimeters of the total 
area requirement.
    S5.2.2.2  Buses with GVWR of more than 10,000 pounds. Buses with a 
GVWR of more than 10,000 pounds shall meet the unobstructed openings 
requirements in S5.2.2.1 by providing side exits and at least one rear 
exit that conforms to S5.3 through S5.5. The rear exit shall meet the 
requirements of S5.3 through S5.5 when the bus is upright and when the 
bus is overturned on either side, with the occupant standing facing the 
exit. When the bus configuration precludes installation of an accessible 
rear exit, a roof exit that meets the requirements of S5.3 through S5.5 
when the bus is overturned on either side, with the occupant standing 
facing the exit, shall be provided in the rear half of the bus.
    S5.2.2.3  Buses with GVWR of 10,000 pounds or less. Buses other than 
school buses with GVWR of 10,000 pounds or less may meet the 
unobstructed openings requirement in S5.2.2.1 by providing:
    (a) Devices that meet the requirements of S5.3 through S5.5 without 
using remote controls or central power systems;
    (b) Windows that can be opened manually to a position that provides 
an opening large enough to admit unobstructed passage, keeping a major 
axis horizontal at all times, of an ellipsoid generated by rotating 
about its minor axis an ellipse having a major axis of 50 centimeters 
and a minor axis of 33 centimeters; or
    (c) Doors.
    S5.2.3  School buses. Except as provided in S5.2.3.4, each school 
bus shall comply with S5.2.3.1 through S5.2.3.3.

[[Page 638]]

    S5.2.3.1.  Each school bus shall be equipped with the exits 
specified in either S5.2.3.1(a) or S5.2.3.1(b), chosen at the option of 
the manufacturer.
    (a) One rear emergency door that opens outward and is hinged on the 
right side (either side in the case of a bus with a GVWR of 10,000 
pounds or less), and the additional exits, if any, specified by Table 1.
    (b) One emergency door on the vehicle's left side that is hinged on 
its forward side and meets the requirements of S5.2.3.2(a), and a push-
out rear window that provides a minimum opening clearance 41 centimeters 
high and 122 centimeters wide and meets the requirements of S5.2.3.2(c), 
and the additional exits, if any, specified by Table 2.

                                 Table 1
------------------------------------------------------------------------
            Seating capacity               Additional exits required *
------------------------------------------------------------------------
1-45...................................  None.
46-62..................................  1 left side exit door or 2 exit
                                          windows.
63-70..................................  1 left side exit door or 2 exit
                                          windows, and 1 roof exit.
71 and above...........................  1 left side exit door or 2 exit
                                          windows, and 1 roof exit, and
                                          any combination of door, roof,
                                          or windows such that the total
                                          capacity credit specified in
                                          Table 3 for these exits, plus
                                          70, is greater than the
                                          seating capacity of the bus.
------------------------------------------------------------------------
* Side emergency exit doors must meet the requirements of S5.2.3.2(a),
  emergency roof exits must meet the requirements of S5.2.3.2(b),
  emergency window exits must meet the requirements of S5.2.3.2(c).


                                 Table 2
------------------------------------------------------------------------
            Seating capacity               Additional exits required *
------------------------------------------------------------------------
1-57...................................  None.
58-74..................................  1 right side exit door or 2
                                          exit windows.
75-82..................................  1 right side exit door or 2
                                          exit windows, and 1 roof exit.
83 and above...........................  1 right side exit door or 2
                                          windows, and 1 ments of S5.3
                                          through S5.5 when the bus is
                                          overturned on either side,
                                          with the occupant standing
                                          facing the exit, shall be
                                          provided in the rear half of
                                          the bus.
------------------------------------------------------------------------

    S5.2.2.3  Buses with GVWR of 10,000 pounds or less. Buses other than 
school buses with GVWR of 10,000 pounds or less may meet the 
unobstructed openings requirement in S5.2.2.1 by providing:
    (a) Devices that meet the requirements of S5.3 through S5.5 without 
using remote controls or central power systems;
    (b) Windows that can be opened manually to a position that provides 
an opening large enough to admit unobstructed passage, keeping a major 
axis horizontal at all times, of an ellipsoid generated by rotating 
about its minor axis an ellipse having a major axis of 50 centimeters 
and a minor axis of 33 centimeters; or
    (c) Doors.
    S5.2.3  School buses. Except as provided in S5.2.3.4, each school 
bus shall comply with S5.2.3.1 through S5.2.3.3.
    S5.2.3.1.  Each school bus shall be equipped with the exits 
specified in either S5.2.3.1(a) or S5.2.3.1(b), chosen at the option of 
the manufacturer.
    (a) One rear emergency door that opens outward and is hinged on the 
right side (either side in the case of a bus with a GVWR of 10,000 
pounds or less), and the additional exits, if any, specified by Table 1.
    (b) One emergency door on the vehicle's left side that is hinged on 
its forward side and meets the requirements of S5.2.3.2(a), and a push-
out rear window that provides a minimum opening clearance 41 centimeters 
high and 122 centimeters wide and meets the requirements of S5.2.3.2(c), 
and the additional exits, if any, specified by Table 2.

                                 Table 1
------------------------------------------------------------------------
            Seating capacity               Additional exits required *
------------------------------------------------------------------------
1-45...................................  None.
46-62..................................  1 left side exit door or 2 exit
                                          windows.
63-70..................................  1 left side exit door or 2 exit
                                          windows, and 1 roof exit.
71 and above...........................  1 left side exit door or 2 exit
                                          windows, and 1 roof exit, and
                                          any combination of door, roof,
                                          or windows such that the total
                                          capacity credit specified in
                                          Table 3 for these exits, plus
                                          70, is greater than the
                                          seating capacity of the bus.
------------------------------------------------------------------------
* Side emergency exit doors must meet the requirements of S5.2.3.2(a),
  emergency roof exits must meet the requirements of S5.2.3.2(b),
  emergency window exits must meet the requirements of S5.2.3.2(c).


                                 Table 2
------------------------------------------------------------------------
            Seating capacity               Additional exits required *
------------------------------------------------------------------------
1-57...................................  None.
58-74..................................  1 right side exit door or 2
                                          exit windows.
75-82..................................  1 right side exit door or 2
                                          exit windows, and 1 roof exit.

[[Page 639]]


83 and above...........................  1 right side exit door or 2
                                          windows, and 1 roof exit, and
                                          any combination of door, roof,
                                          or windows such that the total
                                          capacity credit specified in
                                          Table 3 for these exits plus
                                          82 is greater than the
                                          capacity of the bus.
------------------------------------------------------------------------
* Side emergency exit doors must meet the requirements of S5.2.3.2(a),
  emergency roof exits must meet the requirements of S5.2.3.2(b),
  emergency window exits must meet the requirements of S5.2.3.2(c).


                                 Table 3
------------------------------------------------------------------------
                                                                Capacity
                           Exit Type                             Credit
------------------------------------------------------------------------
Side Door.....................................................        16
Window........................................................         8
Roof Exit.....................................................         8
------------------------------------------------------------------------

    (c) The area of an opening equipped with a wheelchair lift may be 
credited toward the required additional exits if it meets the 
requirements of paragraphs (a) or (b) of S5.2.3.1 and if the lift folds 
or stows in such a manner that the area is available for use by persons 
not needing the lift. With the lift in the folded or stowed position, 
such opening is considered a side emergency exit door.
    S5.2.3.2  All emergency exits required by S5.2.3.1(a) and 
S5.2.3.1(b) shall meet the following criteria:
    (a) Side emergency exit doors.
    (1) Each side emergency exit door shall be hinged on its forward 
side.
    (2) The first side emergency exit door installed pursuant to Table 
1, shall be located on the left side of the bus and as near as 
practicable to the mid-point of the passenger compartment. A second side 
emergency exit door installed pursuant to Table 1 shall be located on 
the right side of the bus. In the case of a bus equipped with three side 
emergency door exits pursuant to Table 1, the third shall be located on 
the left side of the bus.
    (3) The first side emergency exit door installed pursuant to Table 2 
shall be located on the right side of the bus. A second side emergency 
door exit installed pursuant to Table 2 shall be located on the left 
side of the bus. In the case of a bus equipped with three side emergency 
door exits pursuant to Table 2, the third shall be located on the right 
side of the bus.
    (4) No two side emergency exit doors shall be located, in whole or 
in part, within the same post and roof bow panel space.
    (b) Emergency roof exit. (1) Each emergency roof exit shall be 
hinged on its forward side, and shall be operable from both inside and 
outside the vehicle.
    (2) In a bus equipped with a single emergency roof exit, the exit 
shall be located as near as practicable to the midpoint of the passenger 
compartment.
    (3) In a bus equipped with two emergency roof exits, one shall be 
located as near as practicable to a point equidistant between the 
midpoint of the passenger compartment and the foremost limit of the 
passenger compartment and the other shall be located as near as 
practicable to a point equidistant between the midpoint of the passenger 
compartment and the rearmost point of the passenger compartment.
    (4) In a bus equipped with three or more emergency roof exits, the 
roof exits shall be installed so that, to the extent practicable, the 
longitudinal distance between each pair of adjacent roof exits is the 
same and equal to the distance from the foremost point of the passenger 
compartment to the foremost roof exit and to the distance from the 
rearmost point of that compartment to the rearmost roof exit.
    (5) Except as provided in paragraph (b)(6) of this section, each 
emergency roof exit shall be installed with its longitudinal centerline 
coinciding with a longitudinal vertical plane passing through the 
longitudinal centerline of the school bus.
    (6) In a bus equipped with two or more emergency roof exits, for 
each roof exit offset from the longitudinal vertical plane specified in 
paragraph (b)(5) of this section, there shall be another roof exit 
offset from that plane an equal distance to the other side.
    (c) Emergency exit windows. A bus equipped with emergency exit 
windows shall have an even number of such windows, not counting the 
push-out rear window required by S5.2.3.1(b). Any side emergency exit 
windows shall be evenly divided between the right and left sides of the 
bus. School buses shall

[[Page 640]]

not be equipped with horizontally-sliding emergency exit windows. 
Further, except for buses equipped with rear push-out emergency exit 
windows in accordance with S5.2.3.1(b), school buses shall not be 
equipped with both sliding and push-out emergency exit windows.
    S5.2.3.3 The engine starting system of a bus shall not operate if 
any emergency exit is locked from either inside or outside the bus. For 
purposes of this requirement, ``locked'' means that the release 
mechanism cannot be activated and the exit opened by a person at the 
exit without a special device such as a key or special information such 
as a combination.
    S5.2.3.4  Each school bus manufactured before September 1, 1994 may, 
at the manufacturer's option, comply with either S5.2.3.4(a) or 
S5.2.3.4(b) instead of S5.2.3.1 through S5.2.3.3.
    (a) Each bus shall be equipped with one rear emergency door that 
opens outward and is hinged on the right side (either side in the case 
of a bus with a GVWR of 4,536 kilograms or less); or
    (b) Each bus shall be equipped with one emergency door on the 
vehicle's left side that is hinged on its forward side and meets the 
requirements of S5.2.3.2(a), and a push-out rear window that provides a 
minimum opening clearance 41 centimeters high and 122 centimeters wide 
and meets the requirements of S5.2.3.2(c).
    S5.3  Emergency exit release.
    S5.3.1  Each emergency exit not required by S5.2.3 shall be 
releasable by operating one or two mechanisms located within the regions 
specified in Figure 1, Figure 2, or Figure 3. The lower edge of the 
region in Figure 1, and Region B in Figure 2, shall be located 13 
centimeters above the adjacent seat, or 5 centimeters above the arm 
rest, if any, whichever is higher.
    S5.3.2  When tested under the conditions of S6., both before and 
after the window retention test required by S5.1, each emergency exit 
not required by S5.2.3 shall allow manual release of the exit by a 
single occupant using force applications each of which conforms, at the 
option of the manufacturer, either to S5.3.2 (a) or (b) of this section. 
Each exit shall have not more than two release mechanisms. In the case 
of exits with one release mechanism, the mechanism shall require two 
force applications to release the exit. In the case of exits with two 
release mechanisms, each mechanism shall require one force application 
to release the exit. At least one of the force applications for each 
exit shall differ from the direction of the initial motion to open the 
exit by not less than 90 deg. and no more than 180 deg..
    (a) Low-force application.
    (1) Location. As shown in Figure 1 or Figure 3.
    (2) Type of motion. Rotary or straight.
    (3) Magnitude. Not more than 20 pounds.
    (b) High force application.
    (1) Location. As shown in Figure 2 or Figure 3.
    (2) Type of motion. Straight, perpendicular to the undisturbed exit 
surface.
    (3) Magnitude. Not more than 60 pounds.
    S5.3.3 School bus emergency exit release.
    S5.3.3.1  When tested under the conditions of S6., both before and 
after the window retention test required by S5.1, each school bus 
emergency exit door shall allow manual release of the door by a single 
person, from both inside and outside the passenger compartment, using a 
force application that conforms to S5.3.3.1 (a) through (c) of this 
section, except a school bus with a GVWR of 10,000 pounds or less is not 
required to conform to S5.3.3.1 (a). The release mechanism shall operate 
without the use of remote controls or tools, and notwithstanding any 
failure of the vehicle's power system. When the release mechanism is not 
in the position that causes an emergency exit door to be closed and the 
vehicle's ignition is in the ``on'' position, a continuous warning sound 
shall be audible at the driver's seating position and in the vicinity of 
the emergency exit door.
    (a) Location: Within the high force access region shown in Figure 3A 
for a side emergency exit door, and in figure 3D for a rear emergency 
exit door.
    (b) Type of motion: Upward from inside the bus and, at the 
discretion of the manufacturer, from outside the bus. Buses with a GVWR 
of 10,000 pounds or less shall provide interior release mechanisms that 
operate by either an upward or pull-type motion.

[[Page 641]]

The pull-type motion shall be used only when the release mechanism is 
recessed in such a manner that the handle, level, or other activating 
device, before being activated, does not protrude beyond the rim of the 
recessed receptacle.
    (c) Magnitude of force: Not more than 178 newtons.
    S5.3.3.2  When tested under the conditions of S6., both before and 
after the window retention test required by S5.1, each school bus 
emergency exit window shall allow manual release of the exit by a single 
person, from inside the passenger compartment, using not more than two 
release mechanisms located in specified low-force or high-force regions 
(at the option of the manufacturer) with force applications and types of 
motions that conform to either S5.3.3.2 (a) or (b) of this section. In 
the case of windows with one release mechanism, the mechanism shall 
require two force applications to release the exit. In the case of 
windows with two release mechanisms, each mechanism shall require one 
application to release the exit. At least one of the force applications 
for each window shall differ from the direction of the initial motion to 
open the exit by no less than 90 deg. and no more than 180 deg.. Each 
release mechanism shall operate without the use of remote controls or 
tools, and notwithstanding any failure of the vehicle's power system. 
When a release mechanism is open and the vehicle's ignition is in the 
``on'' position, a continuous warning shall be audible at the drivers 
seating position and in the vicinity of that emergency exit.
    (a) Emergency exit windows--Low-force application.
    (1) Location: Within the low-force access regions shown in Figures 1 
and 3 for an emergency exit window.
    (2) Type of motion: Rotary or straight.
    (3) Magnitude: Not more than 89 newtons.
    (b) Emergency exit windows--High-force application.
    (1) Location: Within the high-force access regions shown in Figures 
2 and 3 for an emergency exit window.
    (2) Type of motion: Straight and perpendicular to the undisturbed 
exit surface.
    (3) Magnitude: Not more than 178 newtons.
    S5.3.3.3  When tested under the conditions of S6., both before and 
after the window retention test required by S5.1, each school bus 
emergency roof exit shall allow manual release of the exit by a single 
person from both inside and outside the passenger compartment, using not 
more than two release mechanisms located at specified low-force or high-
force regions (at the option of the manufacturer) with force 
applications and types of motions that conform either to S5.3.3.3 (a) or 
(b) of this section. In the case of roof exits with one release 
mechanism, the mechanism shall require two force applications to release 
the exit. In the case of roof exits with two release mechanisms, each 
mechanism shall require one application to release the exit. At least 
one of the force applications for each roof exit shall differ from the 
direction of the initial push-out motion of the exit by no less than 
90 deg. and no more than 180 deg..
    (a) Emergency roof exits--Low-force application.
    (1) Location: Within the low force access regions shown in Figure 
3B, in the case of buses whose roof exits are not offset from the plane 
specified in S5.2.3.2(b)(5). In the case of buses which have roof exits 
offset from the plane specified in S5.2.3.2(b)(5), the amount of offset 
shall be used to recalculate the dimensions in Figure 3B for the offset 
exits.
    (2) Type of motion: Rotary or straight.
    (3) Magnitude: Not more than 89 newtons.
    (b) Emergency roof exits--High-force application.
    (1) Location: Within the high force access regions shown in Figure 
3B, in the case of buses whose roof exits are not offset from the plane 
specified in S5.2.3.2(b)(5). In the case of buses which have roof exits 
offset from the plane specified in S5.2.3.2(b)(5), the amount of offset 
shall be used to recalculate the dimensions in Figure 3B for the offset 
exits.
    (2) Type of motion: Straight and perpendicular to the undisturbed 
exit surface.
    (3) Magnitude: Not more than 178 newtons.
    S5.4  Emergency exit opening.

[[Page 642]]

    S5.4.1  After the release mechanism has been operated, each 
emergency exit not required by S5.2.3 shall, under the conditions of 
S6., both before and after the window retention test required by S5.1, 
using the reach distances and corresponding force levels specified in 
S5.3.2, allow manual opening by a single occupant to a position that 
provides an opening large enough to admit unobstructed passage, keeping 
a major axis horizontal at all times, of an ellipsoid generated by 
rotating about its minor axis an ellipse having a major axis of 50 
centimeters and a minor axis of 33 centimeters.
    S5.4.2  School bus emergency exit opening.
    S5.4.2.1  School buses with a GVWR of more than 10,000 pounds.
    (a) Emergency exit doors. After the release mechanism has been 
operated, each emergency exit door of a school bus shall, under the 
conditions of S6., before and after the window retention test required 
by S5.1, using the force levels specified in S5.3.3, be manually 
extendable by a single person to a position that permits:
    (1) In the case of a rear emergency exit door, an opening large 
enough to permit unobstructed passage of a rectangular parallelepiped 
114 centimeters high, 61 centimeters wide, and 30 centimeters deep, 
keeping the 114 centimeter dimension vertical, the 61 centimeter 
dimension parallel to the opening, and the lower surface in contact with 
the floor of the bus at all times; and
    (2) In the case of a side emergency exit door, an opening at least 
114 centimeters high and 61 centimeters wide.
    (i) Except as provided in paragraph (a)(2)(ii) of this section, no 
portion of a seat or a restraining barrier shall be installed within the 
area bounded by the opening of a side emergency exit door, a vertical 
transverse plane tangent to the rearward edge of the door opening frame, 
a vertical transverse plane parallel to that plane at a distance of 30 
centimeters forward of that plane, and a longitudinal vertical plane 
passing through the longitudinal centerline of the bus. (See Figure 5A).
    (ii) A seat bottom may be located within the area described in 
paragraph (a)(2)(i) of this section 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 area described in 
paragraph (i) when the seat bottom is vertical. (See Figure 5B).
    (iii) No portion of a seat or restraining barrier located forward of 
the area described in paragraph (a)(2)(i) of this section and between 
the door opening and a longitudinal vertical plane passing through the 
longitudinal centerline of the bus shall extend rearward of a vertical 
transverse plane tangent to the forwardmost portion of a latch mechanism 
on the door. (See Figures 5B and 5C.)
    (3)(i) Each emergency exit door of a school bus shall be equipped 
with a positive door opening device that, after the release mechanism 
has been operated, under the conditions of S6, before and after the 
window retention test required by S5.1--
    (A) Bears the weight of the door;
    (B) Keeps the door from closing past the point at which the door is 
perpendicular to the side of the bus body, regardless of the body's 
orientation; and
    (C) Provides a means for release or override.
    (ii) The positive door opening device shall perform the functions 
specified in paragraph (a)(3)(i) (A) and (B) of this section without the 
need for additional action beyond opening the door past the point at 
which the door is perpendicular to the side of the bus body.
    (b) Emergency roof exits. After the release mechanism has been 
operated, each emergency roof exit of a school bus shall, under the 
conditions of S6, before and after the window retention test required by 
S5.1, using the force levels specified in S5.3.3, be manually extendable 
by a single person to a position that permits an opening at least 41 
centimeters high and 41 centimeters wide.
    (c) Emergency exit windows. After the release mechanism has been 
operated, each emergency exit window of a school bus shall, under the 
conditions of S6., both before and after the window retention test of 
S5.1, using force levels specified in S5.3.3.2, be manually extendable 
by a single occupant to a position that provides an opening large enough 
to admit unobstructed passage,

[[Page 643]]

keeping a major axis horizontal at all times, of an ellipsoid generated 
by rotating about its minor axis an ellipse having a major axis of 50 
centimeters and a minor axis of 33 centimeters.
    S5.4.2.2  School buses with a GVWR of 10,000 pounds or less. A 
school bus with a GVWR of 10,000 pounds or less shall conform to all the 
provisions of S5.4.2, except that the parallelepiped dimension for the 
opening of the rear emergency door or doors shall be 45 inches high, 22 
inches wide, and six inches deep.
    S5.5  Emergency exit identification.
    S5.5.1  In buses other than school buses, and except for windows 
serving as emergency exits in accordance with S5.2.2.3(b) and doors in 
buses with a GVWR of 10,000 pounds or less, each emergency exit door 
shall have the designation ``Emergency Door'' or ``Emergency Exit,'' and 
every other emergency exit shall have the designation ``Emergency Exit'' 
followed by concise operating instructions describing each motion 
necessary to unlatch and open the exit, located within 16 centimeters of 
the release mechanism.

    Examples:

    (1) Lift to Unlatch, Push to Open
    (2) Lift Handle and Push out to Open

When a release mechanism is not located within an occupant space of an 
adjacent seat, a label meeting the requirements of S5.5.2 that indicates 
the location of the nearest release mechanism shall be placed within the 
occupant space.

    Example: ``Emergency Exit Instructions Located Next to Seat Ahead''

    S5.5.2  In buses other than school buses. Except as provided in 
S5.5.2.1, each marking shall be legible, when the only source of light 
is the normal nighttime illumination of the bus interior, to occupants 
having corrected visual acuity of 20/40 (Snellen ratio) seated in the 
adjacent seat, seated in the seat directly adjoining the adjacent seat, 
and standing in the aisle location that is closest to that adjacent 
seat. The marking shall be legible from each of these locations when the 
other two corresponding locations are occupied.
    S5.5.2.1  If the exit has no adjacent seat, the marking must meet 
the legibility requirements of S5.5.2 for occupants standing in the 
aisle location nearest to the emergency exit, except for a roof exit, 
which must meet the legibility requirements for occupants positioned 
with their backs against the floor opposite the roof exit.
    S5.5.3 School Bus.
    (a) Each school bus emergency exit provided in accordance with 
S5.2.3.1 shall have the designation ``Emergency Door'' or ``Emergency 
Exit,'' as appropriate, in letters at least 5 centimeters high, of a 
color that contrasts with its background. For emergency exit doors, the 
designation shall be located at the top of, or directly above, the 
emergency exit door on both the inside and outside surfaces of the bus. 
The designation for roof exits shall be located on an inside surface of 
the exit, or within 30 centimeters of the roof exit opening. For 
emergency window exits, the designation shall be located at the top of, 
or directly above, or at the bottom of the emergency window exit on both 
the inside and outside surfaces of the bus.
    (b) Concise operating instructions describing the motions necessary 
to unlatch and open the emergency exit shall be located within 15 
centimeters of the release mechanism on the inside surface of the bus. 
These instructions shall be in letters at least 1 centimeter high and of 
a color that contrasts with its background.

    Examples:

    (1) Lift to Unlatch, Push to Open
    (2) Turn Handle, Push Out to Open

    (c) Each opening for a required emergency exit shall be outlined 
around its outside perimeter with a retroreflective tape with a minimum 
width of 2.5 centimeters and either red, white, or yellow in color, that 
when tested under the conditions specified in S6.1 of Standard No. 131 
(49 CFR 571.131), meets the criteria specified in Table 1 of that 
section.
    S6. Test conditions.
    S6.1  The vehicle is on a flat, horizontal surface.
    S6.2  The inside of the vehicle and the outside environment are kept 
at any temperature from 70 deg. to 85  deg.Fahrenheit for 4 hours 
immediately

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preceding the tests, and during the tests.
    S6.3  For the window retention test, windows are installed, closed, 
and latched (where latches are provided) in the condition intended for 
normal bus operation.
    S6.4  For the emergency exit release and extension tests, windows 
are installed as in S6.3, seats, armrests, and interior objects near the 
windows are installed as for normal use, and seats are in the upright 
position.

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[37 FR 9395, May 10, 1972, as amended at 37 FR 18035, Sept. 6, 1972; 38 
FR 6070, Mar. 6, 1973; 38 FR 7562, Mar. 28, 1973; 39 FR 15274, May 2, 
1974; 40 FR 48512, Oct. 16, 1975; 41 FR 3872, Jan. 27, 1976; 41 FR 
22357, June 3, 1976; 41 FR 24592, June 17, 1976; 41 FR 36027, Aug. 26, 
1976; 47 FR 7256, Feb. 18, 1982; 47 FR 37555, Aug. 26, 1982; 57 FR 
49423, Nov. 2, 1992; 57 FR 57020, Dec. 2, 1992; 59 FR 22999, May 4, 
1994; 60 FR 24570, May 9, 1995]

    Effective Date Note: At 67 FR 19351, Apr. 19, 2002, Sec. 571.217 was 
amended by adding in S4, in alphabetical order, the definitions of 
``wheelchair,'' ``wheelchair securement anchorage'', and ``wheelchair 
securement device'', by revising S5.4.2.1(a)(1) by adding S5.4.3 and 
S5.5.3(d) and by adding after Figure 5C, Figure 6A, Figure 6B, Figure 
6C, and Figure 6D, effective Apr. 21, 2003. For the convenience of the 
user, the revised and added text is set forth as follows:

Sec. 571.217  Standard No. 217; Bus emergency exits and window retention 
          and release.

                                * * * * *

    S4. * * *
    Wheelchair means a wheeled seat frame for the support and conveyance 
of a physically disabled person, comprising at least a frame, seat, and 
wheels.

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    Wheelchair securement anchorage means the provision for transferring 
wheelchair securement device loads to the vehicle structure.
    Wheelchair securement device means a strap, webbing or other device 
used for securing a wheelchair to the school bus, including all 
necessary buckles and other fasteners.

                                * * * * *

    S5.4.2.1 * * *
    (a) * * *
    (1) In the case of a rear emergency exit door, an opening large 
enough to permit unobstructed passage into the bus of a rectangular 
parallelepiped 1,145 millimeters (45 inches) high, 610 millimeters (24 
inches) wide, and 305 millimeters (12 inches) deep, keeping the 1,145 
millimeter (45 inch) dimension vertical, the 610 (24 inch) millimeter 
dimension parallel to the opening, and the lower surface in contact with 
the floor of the bus at all times, until the bottom edge of the rearmost 
surface of the parallelepiped is tangent to the plane of the door 
opening; and

                                * * * * *

    S5.4.3 Restriction on wheelchair anchorage location.
    S5.4.3.1 Except as provided in paragraph S5.4.3.2 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.
    S5.4.3.2 The restriction in S5.4.3.1(a) of this section does not 
apply to tracks or track-type devices that are used for mounting seats 
and/or for wheelchair securement devices.

                                * * * * *

    S5.5.3 School Bus.

                                * * * * *

    (d) On the inside surface of each school bus, there shall be a label 
directly beneath or above each ``Emergency Door'' or ``Emergency Exit'' 
designation required by paragraph (a) of S5.5.3 of this standard for an 
emergency exit door or window. The label shall state, in letters at 
least 25 mm (one inch) high, the words ``DO NOT BLOCK'' in a color that 
contrasts with the background of the label.

                                * * * * *

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