Ariz. Admin. Code § 13-13-107

Current through Register Vol. 30, No. 49, December 6, 2024

Section R13-13-107 - Minimum Standards for School Bus Body

The body of a school bus introduced to Arizona on or after May 31, 2008 shall meet the requirements of this Section . The body of a school bus introduced to Arizona before May 31, 2008 shall meet the requirements of this Section or shall be maintained in accordance with the manufacturer's original specifications.

1. Air conditioning system: The school bus may be installed with an air conditioning system. If installed, the air conditioning system shall:

a. Be of a mechanical vapor compression refrigeration type;

b. Be manufactured to conform to the requirements of Standard J639, June 2005 (no later amendments or editions) published by the Society of Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale, PA 15096-0001, incorporated by reference and on file with the Department;

c. Have sufficient power for simultaneous cooling, circulating, and dehumidifying the air;

d. Be provided with refrigerant that is nontoxic, nonflammable, and non-explosive;

e. Have all power and grounding installed according to the manufacturer's specifications; and

f. Have exhaust system exit from the rear of the vehicle, and extend to, but not more than 2 inches beyond the outer edge of the rear bumper.

2. Aisle:

a. The center aisle of a school bus shall have a clearance of not less than 12 inches at the bottom of the seat cushion, increasing to 15 inches at the top of the seat backs.

b. Aisles to side emergency doors shall have a minimum clearance of 12 inches which may be achieved by using flip-up type seats.

3. Auxiliary fan:

a. An auxiliary fan, if installed, shall be placed in a location that does not obstruct the school bus driver's view of any mirror located on the school bus.

b. An auxiliary fan, if installed, shall have a 6-inch nominal diameter, with the fan blades covered by a protective cage.

c. Each installed auxiliary fan shall be controlled by a switch that is independent of any other electrical system.

4. Battery:

a. A battery shall be secured to a slide-out or swing-out tray in a vented compartment in the school bus body, so the battery is accessible to the outside for servicing. If the battery compartment has a door that is not removable, the door shall be secured by a fastening device when the door is in a closed position. If the battery compartment has a removable cover, the cover shall be secured by a fastening device when the cover is in place.

b. The word "Battery" shall be printed in unshaded black letters that are no more than 2 inches in height on the battery-compartment door or cover or immediately above the battery-compartment door or cover.

c. Buses with a battery located under the engine hood are exempt from these provisions.

5. Belt cutter: A school bus with passenger seat belts shall be equipped with a belt cutter having a full width handgrip and a protected, replaceable or non-corrodible blade. The belt cutter shall be mounted in a location accessible to the seated driver, and in an easily detachable manner. The belt cutter shall be accessible only to the school bus driver.

6. Color:

a. A school bus body shall be painted National School Bus Yellow according to the following specifications and tolerances:

Description	Reflectance	Chromaticity
	Y	X	Y
Centroid	41.5%	.5139	.4434
V+ Light Limit	42.9%	.5139	.4427
V- Dark Limit	39.8%	.5133	.4422
H+ Green Limit	41.6%	.5123	.4368
H- Red Limit	41.7%	.5168	.4489
C+ Vivid Limit	41.5%	.5188	.4457
C- Weak Limit	41.5%	.5095	.4405

b. The bumpers, lamp hoods, lettering, and rub rails on a school bus body shall be black.

7. Crossing control arm:

a. A school bus may be equipped with a crossing control arm. If installed, all components and all connections of the crossing control arm shall:

i. Meet the requirements set forth in Standard J1133, November 2004 (no later amendments or editions) published by the Society of Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale, PA 15096-0001, incorporated by reference and on file with the Department;

ii. Be mounted on the right side of the front bumper;

iii. When opened, extend in a line parallel to the body side and aligned with the right side wheel;

iv. Be weatherproofed;

v. Incorporate system connectors (electrical, vacuum, or air) at the gate and be easily removable to allow for towing of the school bus;

vi. Be constructed of non-corrodible or nonferrous material, or treated in accordance with the school bus body sheet metal specification;

vii. Have no sharp edges or projections that could cause injury or be a hazard to students;

viii. Be rounded at the end of the crossing control arm;

ix. Extend approximately 70 inches (measured from the bumper at the arm assembly attachment point) when in the extended position;

x. Not extend past the end of the bumper when in the stowed position;

xi. Extend simultaneously with the stop signal arm, activated by the stop signal arm control; and

xii. Include a device attached to the bumper near the end of the arm to automatically retain the arm while in the stowed position. The device shall not interfere with the normal operations of the crossing control arm.

b. An automatic recycling interrupt switch may be installed for temporarily disabling the crossing control arm.

8. Defrosters:

a. Defrosting and defogging equipment shall direct a flow of heated air onto the windshield, the window to the left of the driver, and the glass in the viewing area directly to the right of the driver to eliminate frost, fog, and snow.

b. The defrosting system shall conform to Standards J381 September 2000 (no later amendments or editions) and J382, September 2000 (no later amendments or editions), both published by the Society of Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale, PA 15096-0001 incorporated by reference and on file with the Department.

c. An auxiliary fan shall not to be used in place of a defrosting and defogging system.

d. A portable heater shall not be used in place of a defrosting or defogging system.

9. Electrical wiring:

a. All electrical wiring on a school bus shall conform to the standards contained in Standard J1292, October 1981 (no later amendments or editions), published by the Society of Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale, PA 15096-0001 and incorporated by reference and on file with the Department.

b. Electrical wiring that is coded by color shall be coded as follows:

i. Left Rear Directional Light: Yellow

ii. Right Rear Directional Light: Dark Green

iii. Stoplights: Red

iv. Back-up Lights: Blue

v. Taillights: Brown

vi. Ground: White

vii. Ignition Feed, Primary Feed: Black

c. Circuits: Electrical wiring circuits shall be protected by a fuse, circuit breaker, or Field Effect Transistor and shall be coded by number or color on an electrical wiring diagram located in the driver's compartment or the electrical access panel door. There shall be at least seven circuits as follows:

i. Head, tail, stop, and instrument panel lamps;

ii. Clearance and step-well lamps;

iii. Dome lamps;

iv. Ignition and emergency door signal;

v. Turn signal lamps;

vi. Alternately flashing signal lamps; and

vii. Heaters and defrosters.

d. All electrical wires passing through metal openings shall be protected by a non-metal grommet.

e. Electrical wires not enclosed within the school bus body shall be fastened at intervals of not more than 18 inches.

10. Emergency exits: A door, push-out window, or roof hatch used as an emergency exit shall conform to the following:

a. On the inside and outside of a school bus, the words "EMERGENCY EXIT" or "EMERGENCY DOOR" shall be printed in black, unshaded letters at least 2 inches high above an emergency door or push-out window and at least 1 inch high on a roof hatch.

b. Each emergency exit shall open toward the exterior of the school bus and shall be labeled within 6 inches of the interior release mechanism with black lettering at least 3/8 of an inch high instructing how the exit is to be opened.

c. On a Type A school bus with double rear doors used as emergency exits, the rear doors shall be secured with upper, center, and lower latches to the door frame.

d. The upper portion of each door used as an emergency exit shall be equipped with a window made of safety glass with an area not less than 400 square inches. A door located in the rear end of the school bus used as an emergency exit shall also contain a lower window panel of safety glass of not less than 350 square inches. A Type A school bus that contains double rear doors used as emergency exits is exempt from this provision.

e. There shall be no steps on the outside of the school bus leading to an emergency exit.

f. A header pad filled with a material to protect against injury shall be attached to the top edge of the frame of a door used as an emergency exit. The header pad shall be a minimum of 3 inches wide and 1 inch thick and extend the full width of the door opening.

g. Each emergency exit shall be equipped with a latch that opens from the inside of the school bus and is connected to an electrical buzzer audible in the driver's compartment that actuates when the latch is being released.

h. Except for interlock/barrel bolt devices, if a lock is installed on an emergency exit, the lock shall be secured only by using a key and shall deactivate the ignition system of the school bus when locked.

11. Emergency equipment:

a. All emergency equipment shall be mounted in the driver's compartment or adjacent to either side of the service entrance and shall be readily accessible. If the emergency equipment is mounted within a closed compartment, the compartment shall be clearly labeled as containing the emergency equipment.

b. Fire extinguisher:

i. A school bus shall be equipped with a minimum of one 5-pound pressurized, dry, chemical fire extinguisher of a type rated not less than 2A-10-BC by the Underwriter's Laboratories, Inc., as described by the National Fire Protection Association, Inc., One Batterymarch Park, Quincy, MA 02269, in NFPA 10: Standard for Portable Fire Extinguishers, published in 2006 (no later amendments or editions), incorporated by reference and on file with the Department.

ii. A pressure gauge shall be mounted on the fire extinguisher to be readable in its mounted position.

iii. The operating mechanism of the fire extinguisher shall be sealed with a type of seal that will not interfere with the use of the fire extinguisher.

c. Warning devices: A school bus shall have a minimum of three reflective triangle road-warning devices that comply with the standards at 49 CFR 571.125, October 2006 (no later amendments or editions), published by the U.S. Government Printing Office, Superintendent of Documents, Mail Stop: SSOP, Washington, D.C. 20402-9328, incorporated by reference and on file with the Department.

12. Floor:

a. The floor beneath the seats, including the tops of the wheel housings and the floor in the driver's compartment, shall be covered with fire-resistant floor-covering material having a minimum overall thickness of .10 inch.

b. The aisle floor shall be covered with a fire-resistant ribbed or non-skid floor-covering material with a minimum thickness of .10 inch.

c. The floor-covering material shall be bonded to the floor with a waterproof adhesive and shall not crack when subjected to changes in air temperature.

13. Handrail: A handrail at a school bus service entrance shall be secured to the school bus wall in a manner that causes the crevice formed by the distance between the handrail and the wall to pass the inspection procedure described by the National Highway Traffic Safety Administration, Washington, D.C. 20590, in School Bus Safety Assurance Program Recall Listing: January 1991 Through June 1996 (no later amendments or editions), incorporated by reference and on file with the Department.

14. Heating system:

a. Heaters shall be of the hot-water type.

b. The heating system shall be capable of maintaining bus interior temperatures as specified in the procedure set forth in Standard J2233, June 2002 (no later amendments or editions), published by the Society of Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale, PA 15096-0001, incorporated by reference and on file with the Department.

c. A minimum of one heater shall be a fresh-air or combination fresh-air and recirculating-air type.

d. If more than one heater is used, additional heaters may be of recirculating-air type.

e. All heater hoses shall be secured in all areas of the school bus body and chassis to prevent wear due to vibration. Heater lines in the interior of the bus shall be covered by a protective shield to prevent scalding of the driver or passengers.

f. Except on Type A school buses, the heater system shall include shutoff valves installed at the engine in the water pressure lines and return lines.

15. Identification:

a. Only signs, lettering, and objects approved by state law or these rules shall appear on the interior or exterior of a school bus, including all glass areas.

b. Each school bus owned by a school or a private company shall display either the name of the school and school number, if any, or the name of the private company on each exterior side of the school bus between the rub rails at the center line and seat cushion levels in black unshaded letters that are at least 5 inches in height. Additionally, a school bus owned by a private company that displays the name of the school and school number as described above, may display the company's name on each exterior side of the school bus below the floor line in black unshaded letters that are a maximum of 2 inches in height.

c. An identification number assigned to a school bus by an owner shall be placed on the front and rear bumpers of the school bus and on each exterior side of the school bus below the floor line rub rail and forward of the cen-terline of the school bus. The identification number on each bumper shall be National School Bus Yellow. The identification number on each exterior side shall be black. Each identification number shall be a minimum of 5 inches in height.

d. In addition to an identification number, a school bus may be identified by an emblem placed on the loading side of the front bumper or the exterior wall of the loading side below the floor line rub rail and forward of the center line of the school bus, or both. The emblem shall be painted or decaled on or attached to a magnetic backing.

e. In addition to an identification number, a school bus may display a route identification sign. If displayed, the route identification sign shall:

i. Be installed with a heavy duty Velcro, magnetic, screw-type or similar fixture;

ii. Be a minimum of 5 inches in height; and

iii. Be located on a flat surface of the bus body, excluding glass.

16. Interior: If the ceiling is constructed with overlapping panels, the first panel placed in the ceiling shall be overlapped by the following panel and each panel shall consecutively overlap to the rear end of the school bus. Exposed edges in the interior of the school bus shall be beaded, hemmed, flanged, or rounded to eliminate sharp edges.

17. Lamps and signals:

a. All lamps on the exterior of a school bus shall conform to the provisions contained in 49 CFR 393.9 et seq. of the Federal Motor Carrier Safety Regulations, October, 2006 (no later amendments or editions) published at the U.S. Government Printing Office, Superintendent of Documents, Mail Stop: SSOP, Washington, D.C. 20402-9328, incorporated by reference and on file with the Department.

b. Interior lamps shall be provided that illuminate the center aisle and step well.

c. Alternately flashing signal lamps:

i. When a school bus is equipped with a four-lamp system, the system shall consist of two red alternately flashing signal lamps located one on the left and one on the right above the rear windows of the school bus and two red alternately flashing signal lamps located one on the left and one on the right above the windshield.

ii. When a school bus is equipped with an eight-lamp system, the four red alternately flashing signal lamps shall be installed as described in subsection (14)(c)(i) and the four amber alternately flashing signal lamps shall be installed as follows: one amber alternately flashing signal lamp shall be located adjacent to each red alternately flashing signal lamp, at the same level, but closer to the vertical centerline of the school bus. The system of red and amber alternately flashing signal lamps shall be wired so the amber alternately flashing signal lamps are activated manually and the red alternately flashing signal lamps are activated automatically or manually.

iii. Except for LED lamps, each alternately flashing signal lamp shall be covered by a lamp hood.

d. Turn signal and stop lamps:

i. Except as provided in subsections (17)(d)(iii) and (17)(d)(iv), all school buses shall be equipped with amber side-mounted turn signals. The turn signal lamp on the left side of the bus may be mounted rearward of the stop signal arm and the turn signal lamp on the right side may be mounted rearward of the entrance door.

ii. Except on Type A school buses, a school bus body shall be equipped with rear turn signal lamps that are at least 7 inches in diameter, or if the lamp shape is other than round, a minimum of 38 square inches of illuminated area. The lens area of the rear turn signal lamps on Type A school buses shall be at least 21 square inches. The rear turn signal lamps shall be connected to the hazard warning switch located in the driver's compartment to allow the school bus driver to activate simultaneous flashing of turn signal lamps when needed as a traffic hazard warning. The rear turn signal lamps shall be located to the far left and right sides of the flat surface of the rear of the school bus body and below the rear window.

iii. A Type C school bus may have a double-faced turn signal lamp that is visible from the front and rear of the school bus and mounted on the tops or sides of both front fenders or may have a turn signal lamp mounted on the left and right sides of the grill and may have a turn signal lamp mounted on each side of the school bus body between the window line and the second rub rail and forward of the vertical centerline.

iv. A Type D school bus may have a turn signal lamp mounted at the front of the school bus body above each head lamp and may have a turn signal lamp mounted on each side of the school bus body between the window line and second rub rails and forward of the vertical centerline of the school bus.

v. A 7 inch diameter stop lamp, or if the lamp shape is other than round, a stop lamp with a minimum of 38 square inches of illuminated area shall be located toward the centerline and adjacent to each of the rear turn signal lamps.

e. Backup lamps: A school bus shall be equipped with two backup lamps with clear lenses, located one on the right and one on the left rear panels below the rear windows.

f. White flashing strobe lamp: If used on a school bus, a strobe lamp shall have a single clear lens that emits light 360 degrees around its vertical axis and shall be located on the longitudinal centerline of the school bus roof 1/ 3 to 1/2 of the distance forward from the rear of the school bus body unless this placement restricts the view of the strobe lamp.

i. If the view of the strobe lamp is restricted when the strobe lamp is located 1/3 to 1/2 of the distance forward from the rear of the school bus body, the strobe lamp may be mounted immediately to the rear of the roof hatch.

ii. The strobe lamp shall be controlled by a manual switch located in the driver's compartment.

iii. A pilot lamp shall be located in the driver's compartment to show the school bus driver that the strobe lamp is activated.

18. Mirrors:

a. Interior mirror: The interior mirror shall be made of either laminated glass or glass bonded to a backing that will retain the glass in the event of breakage. The interior mirror in Types B, C, and D school buses shall be a minimum of 6 inches in height and 30 inches in length surrounded by a frame with rounded corners. The interior mirror in Type A buses shall be a minimum of 6 inches in height and 16 inches in length.

b. Exterior mirrors: A school bus shall comply with the requirements contained in 49 CFR 571.111, October 2006 (no later amendments or editions), published at the U.S. Government Printing Office, Superintendent of Documents, Mail Stop: SSOP, Washington, D.C. 20402-9328, incorporated by reference and on file with the Department.

19. Noise suppression switch: A school bus shall be equipped with a manual noise suppression switch. Identification shall be provided on or adjacent to the switch, in order to clearly state its purpose and distinguish it from other controls. This switch shall be an on-off type that deactivates body equipment that produces noise, including, at least, the AM-FM radio, heaters, air conditioners, fans, and defrosters. This switch shall not deactivate safety systems, such as windshield wipers or lighting systems.

20. Overall length: The overall length of a school bus shall not exceed 45 feet including accessories.

21. Overall width: The overall width of a school bus shall not exceed 102 inches excluding mirrors.

22. Rear bumper:

a. The rear bumper shall be made of a minimum of 3/16 inch thick pressed steel that is a minimum of 8 inches in total height.

b. The rear bumper shall be wrapped around the back corners of the bus and shall extend toward the front of the school bus for at least 12 inches as measured from the rear-most point of the school bus body at the floor line.

c. The rear bumper shall be attached to the chassis frame and braced to support the rear corners of the bumper.

d. The rear bumper shall extend at least 1 inch beyond the rear-most part of the school bus body as measured at the floor line.

e. The rear bumper shall not be equipped with footholds or handles.

f. A Type A school bus equipped with the chassis manufacturer's rear bumper is exempt from subsections (22)(a) through (22)(c).

23. Restraining barrier:

a. The restraining barrier shall be a minimum of 38 inches high as measured from the interior floor of the school bus to the top of the restraining barrier.

b. The restraining barrier shall be the same width as the seat directly behind the restraining barrier.

24. Rub rails:

a. There shall be no fewer than two rub rails located on a school bus as follows:

i. One rub rail shall be located on each side of the school bus approximately at seat cushion level and shall extend from the rear post of the service door frame completely around the school bus body, excluding the emergency door, to the front post of the school bus driver's window.

ii. One rub rail shall be located on each side of the school bus approximately at the floor line and shall extend from the rear post of the service door frame to the rear corner post of the school bus body and from the front post of the school bus driver's window to the rear corner post on the driver's side

b. Rub rails are not required on emergency doors, special-service entrance door, access panels and compartment doors, and wheel well openings.

c. Each rub rail shall be attached on the outside of the school bus body at each structural post in the school bus body.

d. Each rub rail shall be a minimum of 4 inches in width and constructed of corrugated or ribbed 16-gauge steel.

25. Seat belt for school bus driver: A seat belt for the school bus driver shall be installed in the driver's compartment. The seat belt shall be equipped with a retractor on each side of the school bus driver's seat to keep the seat belt retracted and off the floor when not in use.

26. Seats:

a. Each seat shall have a minimum depth of 15 inches measured from the front of the seat cushion to the seat back.

b. Each seat shall be a minimum of 38 inches in height measured from the interior floor of the school bus to the top of the back cushion.

c. Seat spacing shall meet the requirements of 49 CFR 571.222, October 2006 (no later amendments or editions), published at the U.S. Government Printing Office, Superintendent of Documents, Mail Stop: SSOP, Washington, D. C. 20402-9328, incorporated by reference and on file with the Department. Seat spacing shall not be less than 24 inches between the front of a seat back cushion to the back surface of the cushion on the preceding seat. Seat spacing shall be measured at cushion height, at the center of the seat, on a plane parallel to the center line of the bus. The seat upholstery may be placed against the seat cushion padding, but without compressing the padding, before measurement is taken.

d. The school bus driver's seat shall be adjustable, without the use of tools, both vertically and horizontally for a minimum of 4 inches. Seats with vertical adjustments are not required on Types A and B school buses.

27. Service door:

a. The service door shall be located on the right side of the school bus opposite the school bus driver and within direct view of the school bus driver when seated in the school bus driver's seat. Types A and B school buses are exempt from this provision.

b. The service door shall have a minimum horizontal opening of 24 inches and a minimum vertical opening of 68 inches. Type A school buses shall have a service door with a minimum opening of 1200 square inches.

c. Windows in the upper and lower panels of the service door shall be made of safety glass. The bottom of each lower window panel shall be no more than 10 inches from the top surface of the lower step of the service entrance. The top of each upper window panel shall be no more than 6 inches below the top of the service door. Type A buses are exempt from this provision.

d. To protect passengers' fingers, a flexible rubber material shall be attached by number 10 3/4 inch metal screws to the opening and closing edges of the service door. Type A school buses are exempt from this provision.

e. The service door shall open towards the exterior of the school bus. A Type A school bus is exempt from this provision if the service door is provided by the school bus chassis manufacturer.

f. A header pad, filled with a material to protect against injury, shall be attached to the top edge of the frame of the service door. The header pad shall be at least 3 inches wide and 1 inch thick and extend the full width of the service entrance.

g. A Type A school bus with the chassis manufacturer's standard service entrance is exempt from subsections (27)(a) through (27)(d).

28. Steps:

a. The risers of the steps in the service entrance shall be equal. When plywood is laid over the steel floor of the school bus, the height of the top step may be increased by the thickness of the plywood.

b. The first step at the service entrance shall be no less than 10 inches and no more than 16 inches from the ground.

c. Steps shall be enclosed in the school bus body.

d. Steps shall not extend beyond the side of the school bus body.

e. A handrail not less than 10 inches in length shall be provided inside the doorway.

29. Step treads:

a. All steps, including the floor-line platform area, shall be covered with ribbed or non-skid floor-covering material that is mounted on a metal plate.

b. The metal back of the step tread shall be a minimum 24-gauge cold rolled steel and shall be permanently bonded to the ribbed or non-skid material.

c. If ribbed material is used, the ribbed design shall run from the risers toward the service entrance. Each step tread shall have a 1 1/2 inch white nosing.

30. Stirrup steps: There shall be a handle and at least one folding stirrup step or recessed foothold located on each side of the front of a school bus for accessibility for cleaning the windshield and lamps. Type A school buses are exempt from this provision.

31. Stop signal arm:

a. School buses shall be equipped with a stop signal arm on the left side of the school bus body that extends 90º from the school bus body when opened.

b. The stop signal arm shall be either air or electrically driven, and meet the requirements of Standard J1133, November 2004 (no later amendments or editions) published by the Society of Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale, PA 15096-0001, incorporated by reference and on file with the Department.

c. The stop signal arm shall be an 18-inch octagon, constructed of a red material that reflects light, with the word "STOP" printed on both sides in white letters not less than 5 inches high. Additionally, the word "STOP" may be illuminated by a light-emitting diode system on both sides of the stop signal arm.

32. Sun shield: An interior adjustable transparent sun shield or visor not less than 6 inches x 30 inches with a finished edge shall be installed over the windshield in the driver's compartment. School buses with a gross vehicle weight rating of 10,000 pounds or less are exempt from this provision.

33. Tailpipe:

a. The tailpipe shall extend to, but not more than 2 inches beyond, the outer edge of the rear bumper;

b. The tailpipe shall exit in the rear of the vehicle behind the rear drive axle, and shall be placed according to the manufacturer's specifications; and

c. The tailpipe shall not exit beneath any fuel filler location or beneath any emergency door.

34. Undercoating:

a. The entire underside of the school bus body, including floor sections, cross member and below-floor-line side panels, shall be coated with rust-proofing material for which the material manufacturer has issued to the bus body manufacturer notarized certification that materials meet or exceed all performance and qualitative requirements of paragraph 3.4 of Federal Specification TT-C-520B, Coating Compound, Bituminous, Solvent Type, Underbody (For Motor Vehicles), February 2, 1973 (no later amendments or editions), published by the General Services Administration acting as an agent for the Superintendent of Documents, Washington D.C. 20402, and incorporated by reference and on file with the Department. Modified test procedures shall be used for the following requirements:

i. Salt spray resistance - test modified to 5% salt and 1,000 hours,

ii. Abrasion resistance, and

iii. Fire resistance.

b. Test panels shall be prepared in accordance with paragraph 4.6.12 of Federal Specification TT-C-520B, with a modified procedure requiring that the test shall be made on a 48-hour air-cured film at a thickness recommended by the material manufacturer.

c. Undercoating is not required if the underside of the school bus is constructed of noncorrosive material.

d. The undercoating material shall be applied with suitable airless or conventional spray equipment to the recommended film thickness and shall show no evidence of voids in the cured film.

35. Ventilation: An immovable, non-closing exhaust ventilator shall be installed in the school bus roof.

36. Wheel housing:

a. The wheel-housing opening shall be large enough to allow for the removal of the tire and wheel.

b. The wheel housing shall be constructed of 16-gauge steel or fiberglass of equal strength and sealed to the school bus floor.

c. The wheel housing shall not extend more than 12 inches above the floor inside the school bus body and shall not extend into the emergency door opening.

d. The wheel housing shall provide clearance for tire chains installed on the tires of the driving wheels.

37. Windows: Each side window in the passenger compartment of a school bus body shall provide an unobstructed opening of at least 190 square inches when the window is open.

38. Windshield washer system: A windshield washer system that provides an application of cleaning solution to the windshield shall be installed.

39. Windshield wipers:

a. A windshield wiping system with a minimum of two speeds shall be provided.

b. The windshield wipers shall be operated by one or more air or electric motors.

Ariz. Admin. Code § R13-13-107

Amended by final rulemaking at 21 A.A.R. 3211, effective 1/24/2016.