Ohio Admin. Code 4501-52-03
[Comment: Information regarding availability, as well as the date or applicable version of the materials incorporated by reference in this rule, can be found in paragraphs (C) and (D) of rule 4501-52-01 of the Administrative Code.]
If the lighting device used as a rear turn signal is amber in color, the lighting device shall have no other function than that of a turn signal or vehicular hazard warning flashing lamps.
For the purposes of those provisions within this rule applying to buses having a specific minimum width, overall bus width measurements are to be made from a point on one side or end of a commercial motor vehicle to the same point on the opposite side or end of the vehicle. The following shall be excluded from the measured width of commercial motor vehicles, as applicable: rear view mirrors, turn signal lamps, handholds for cab entry/egress, splash and spray suppressant devices, load induced tire bulge; and all non-property carrying devices, or components thereof that do not extend more than three inches beyond each side of the vehicle.
For the purposes of those provisions within this rule applying to buses having a specific minimum width, overall bus width measurements are to be made from a point on one side or end of a commercial motor vehicle to the same point on the opposite side or end of the vehicle. The following shall be excluded from the measured width of commercial motor vehicles, as applicable: rear view mirrors, turn signal lamps, handholds for cab entry/egress, splash and spray suppressant devices, load induced tire bulge; and all non-property carrying devices, or components thereof that do not extend more than three inches beyond each side of the vehicle.
Each bus eighty inches or more in overall width shall be equipped with two clearance lamps, amber in color, mounted one on each side of the vertical centerline to indicate overall width. The front clearance lamps shall be on the same level and as high as practicable.
Each bus eighty inches or more in overall width shall be equipped with two clearance lamps, red in color, mounted one on each side of the vertical centerline to indicate overall width. The rear clearance lamps shall be on the same level and as high as practicable.
Each bus shall be equipped with two side marker lamps, amber in color, mounted one on each side and located as far to the front as practicable.
Front side marker lamps shall not be located less than fifteen inches above the road surface.
Each bus, with an overall length greater than thirty feet, shall be equipped with two side marker lamps, amber in color, mounted one on each side, at or near the midpoint between the front and rear side marker lamps.
Intermediate side marker lamps shall not be located less than fifteen inches above the road surface.
Each bus shall be equipped with two side marker lamps, red in color, mounted one on each side and located as far to the rear as practicable.
Rear side marker lamps shall not be located less than fifteen inches above the road surface.
Each bus shall be equipped with two reflectors, amber in color, mounted one on each side as far to the front as practicable.
Front side reflectors shall not be located less than fifteen inches or more than sixty inches above the road surface.
Each bus, with an overall length greater than thirty feet, shall be equipped with two side reflectors, amber in color, mounted one on each side, at or near the midpoint between the front and rear side reflectors.
Intermediate side reflectors shall not be located less than fifteen inches or more than sixty inches above the road surface.
Each bus shall be equipped with two side reflectors, red in color, mounted one on each side and located as far to the rear as practicable.
Rear side reflectors shall not be located less than fifteen inches or more than sixty inches above the road surface.
Each bus shall be equipped with two reflectors, red in color, mounted one on each side of the vertical centerline as far apart as practicable.
The rear reflectors shall be on the same level and located not less than fifteen inches or more than sixty inches above the road surface.
Buses manufactured after June 30, 1953, shall have protective devices for electrical circuits arranged so that:
Steering axle brake linings or pads shall have a thickness of not less than three-sixteenth inch at the shoe center for a shoe with a continuous strip of lining; less than one-quarter inch at the shoe center for a shoe with two pads; or worn to the wear indicator if the lining is so marked.
Non-steering axle brake linings or pads shall have a thickness of not less than one-quarter inch or to the wear indicator if the lining is so marked.
Brake linings or pads shall have a thickness of not less than one-eighth inch.
Brake linings or pads shall have a thickness of not less than one-sixteenth inch.
Brake linings or pads shall have a thickness of not less than one-sixteenth inch.
(a) Hydraulic brake systems
A bus manufactured on or after July 1, 1973, and having service brakes activated by hydraulic fluid shall be equipped with a warning signal that performs as follows:
(i) If federal motor vehicle safety standard number 105, 49 C.F.R. section 571.105 was applicable at the time the bus was manufactured, the warning signal shall conform to the requirements of that standard.
(ii) If federal motor vehicle safety standard number 105, 49 C.F.R. section 571.105 was not applicable to the bus at the time the bus was manufactured, the warning signal shall become operative, before or upon application of the brakes in the event of a hydraulic-type complete failure of a partial system. The signal shall be readily audible or visible to the driver.
(b) Air brake systems
A bus having service brakes activated by compressed air shall be equipped, and perform as follows:
(i) The bus shall have a low air pressure warning device that conforms to the following requirements:
(A) If federal motor vehicle safety standard number 121, 49 C.F.R. section 571.121 was applicable to the vehicle at the time it was manufactured, the warning device shall conform to the requirements of that standard.
(B) If federal motor vehicle safety standard number 121, 49 C.F.R. section 571.121 was not applicable to the vehicle at the time it was manufactured, the vehicle shall have a device that provides a readily audible or visible continuous warning to the driver whenever the pressure of the compressed air in the braking system is below a specified pressure, which shall be at least one-half of the compressor governor cutout pressure.
(ii) The bus shall have a pressure gauge which indicates to the driver the pressure in pounds per square inch available for braking.
(c) Vacuum brake systems
Every bus having service brakes activated by vacuum shall be equipped with:
(i) A device that provides a readily audible or visible continuous warning to the driver whenever the vacuum in the bus supply reservoir is less than eight inches of mercury; and
(ii) A vacuum gauge which indicates to the driver the vacuum in inches of mercury available for braking.
(d) Hydraulic brakes applied or assisted by air or vacuum
A bus having a braking system in which hydraulically activated service brakes are applied or assisted by compressed air or vacuum shall be equipped with both a warning signal that conforms to the requirements of paragraph (C)(4)(b)(i)(a) and paragraph (C)(4)(b)(i)(b) of this rule or paragraph (C)(4)(b)(i)(c) of this rule.
(a) Emergency features of the service brake system; or
(b) A system separate from the service brake system.
A control by which the driver applies the emergency brake system shall be located so that the driver can readily operate it when properly restrained by any seat belt assembly provided for the driver's use. The control for applying the emergency brake system may be combined with either the control for applying the service brake system or the control for applying the parking brake system. However, all three controls may not be combined.
The means used to apply the brakes may be located forward of the driver's seat as long as it can be operated manually by the driver when the driver is properly restrained by any seat belt assembly provided for use.
Every bus shall meet this requirement or comply with the rules and regulations in effect at the time of its manufacturer.
Automatic condensate drain valves may be used provided the automatic feature may be operated manually or manual means of draining the reservoir(s) is retained.
Clamp type brake chamber data
| Type | Outside diameter (inches) | Adjustment limit (inches) |
| 6 | 4-1/2 | 1-1/4 |
| 9 | 5-1/4 | 1-3/8 |
| 12 | 5-11/16 | 1-3/8 |
| 16 | 6-3/8 | 1-3/4 |
| 20 | 6-25/32 | 1-3/4 |
| 24 | 7-7/32 | 1-3/4 |
| 30 | 8-3/32 | 2 |
| 36 | 9 | 2-1/4 |
"Long stroke" clamp type brake chamber data
| Type | Outside diameter (inches) | Adjustment limit (inches) |
| 12 | 5-11/16 | 1-3/4 |
| 16 | 6-3/8 | 2 |
| 20 (2-1/2" rated stroke) | 6-25/32 | 2 |
| 20 (3" rated stroke) | 6-25/32 | 2-1/2 |
| 24 (2-1/2" rated stroke) | 7-7/32 | 2 |
| 24 (3" rated stroke) | 7-7/32 | 2-1/2 |
| 30 | 8-3/32 | 2-1/2 |
Bolt type brake chamber data
| Type | Outside diameter (inches) | Adjustment limit (inches) |
| A | 6-15/16 | 1-3/8 |
| B | 9-3/16 | 1-3/4 |
| C | 8-1/16 | 1-3/4 |
| D | 5-1/4 | 1-1/4 |
| E | 6-3/16 | 1-3/8 |
| F | 11 | 2-1/4 |
| G | 9-7/8 | 2 |
Rotochamber data
| Type | Outside diameter (inches) | Adjustment limit (inches) |
| 9 | 4-9/32 | 1-1/2 |
| 12 | 4-13/16 | 1-1/2 |
| 16 | 5-13/32 | 2 |
| 20 | 5-15/16 | 2 |
| 24 | 6-13/32 | 2 |
| 30 | 7-1/16 | 2-1/4 |
| 36 | 7-5/8 | 2-3/4 |
| 50 | 8-7/8 | 3 |
DD-3 brake chamber data
| Type | Outside diameter (inches) | Adjustment limit (inches) |
| 30* | 8-1/8 | 2-1/4 |
| * This chamber has three air lines and is found on motor coaches. |
Wedge brake data
Combined movement of both brake shoe lining scribe marks shall not exceed one-eighth inch.
The steering wheel shall not have any spokes cracked through or missing.
Steering column U-bolts or other positioning parts shall not be loose or missing.
Steering wheel lash parameters
| Steering wheel diameter | Manual steering system | Power steering system |
| 16" or less | 2"+ | 4 1/2"+ |
| 18" | 2 1/4"+ | 4 3/4"+ |
| 19" | 2 3/8"+ | 5"+ |
| 20" | 2 1/2"+ | 51/4"+ |
| 21" | 2 5/8"+ | 5 1/2"+ |
| 22" | 2 3/4"+ | 5 3/4"+ |
Wheels or rims shall not:
Each fuel system shall be located on the bus so that:
Each fuel tank shall be securely attached to the bus in a workmanlike manner.
Each liquid fuel tank shall be legibly and permanently marked by the manufacturer with the following minimum information:
When pressure devices are used to force fuel from a fuel tank, a device which prevents the flow of fuel from the fuel tank if the fuel feed line is broken shall be installed in the fuel system.
Have each fill pipe fitted with a cap that can be fastened securely over the opening in the fill pipe. (Screw threads or a bayonet-type joint are examples of methods of conforming to the requirements of this paragraph.)
Joints shall not be closed solely by crimping or by soldering with a lead-based or other soft solder;
The air vent may be combined with the fill-pipe cap or safety vent, or it may be a separate unit installed on the fuel tank;
(a) The tank cannot be filled, in a normal filling operation, with a quantity of fuel that exceeds ninety-five per cent of the tank's liquid capacity; and
(b) When the tank is filled, normal expansion of the fuel will not cause fuel spillage.
A fuel system that uses liquefied petroleum gas as a fuel for the operation of a motor vehicle or for the operation of auxiliary equipment installed on, or used in connection with a bus shall conform as follows:
The rear-impact guard(s) shall be substantially constructed and attached by means of bolts, welding, or other comparable means.
The glazing material shall be marked in accordance with federal motor vehicle safety standard number 205, 49 C.F.R. 571.205,(S6) .
The transmittance of not less than seventy per cent does not apply to other windows on the bus.
These devices shall be located outside the area swept by the windshield wipers, and outside the driver's sight lines to the road and highway signs and signals.
The adequacy of such means of escape shall be determined in accordance with the following standards:
(a) It will provide an unobstructed opening sufficient to contain an ellipse having a major axis of eighteen inches and a minor axis of thirteen inches; or
(b) An opening containing two hundred square inches formed by a rectangle thirteen inches by seventeen and three-fourths inches with corner arcs of six inch radius.
(c) The major axis of the ellipse and the long axis of the rectangle shall make an angle of not more than forty-five degrees with the surface on which the unladen bus stands.
(d) The area shall be measured either by removal of the glazing if not of the push-out type or of the movable sash if of the push-out type, and it shall be either glazed with laminated safety glass or comply with paragraph (M)(4) of this rule.
(e) No less than forty per cent of such prescribed glazing or opening shall be on one side of any bus.
Buses required to meet the requirements of this section may conform to the requirements of paragraph (M)(4)(b) of this rule.
Each emergency door shall have such door clearly marked in letters at least one inch in height with the words:
Windshield wiper blades shall be in such condition as to provide clear vision for the driver, unless one such blade be so arranged as to clean an area of the windshield extending to within one inch of the limit of vision through the windshield at each side.
The installation and use of the following types of heaters is prohibited:
Any type of exhaust heater in which the engine exhaust gases are conducted into or through any space occupied by persons or any heater which conducts engine compartment air into any such space;
Any type of heater employing a flame which is not fully enclosed;
Any type of heater from the burner of which there could be spillage or leakage of fuel upon the tilting or overturning of the vehicle in which it is mounted;
Portable heaters shall not be used in any space normally occupied by persons;
Every heater shall be so located or protected as to prevent contact therewith by occupants, unless the surface temperature of the protecting grilles or of any exposed portions of the heaters, inclusive of exhaust stacks, pipes, or conduits shall be lower than would cause contact burns.
(a) Be so designed and constructed as to prevent leakage between the chambers; and
(b) The materials used in such joints shall have melting points substantially higher than the maximum temperatures likely to be attained at the points of jointure.
(a) When necessary, suitable protection shall be afforded by shielding or other means against the puncturing of any such tank or its connection by flying stones or other objects.
(b) Gravity or siphon feed is prohibited for heaters using liquid fuels.
(c) Heaters using liquid fuels shall be equipped with automatic means for shutting off the fuel or for reducing such flow of fuel to the smallest practicable magnitude, in the event of overturn of the vehicle.
Heaters subject to this section and not provided with automatic controls shall be provided with "tell-tale" means to indicate to the driver that the heater is functioning properly.
Every bus shall be equipped with a means for preventing and/or removing the accumulation of ice, snow, frost or condensation that could obstruct the driver's view through the windshield.
All rear-vision mirrors must be easily adjustable and must be capable of holding, during normal operations, any adjustment.
Mirrors installed on a bus manufactured prior to January 1, 1981, may be continued in service, provided that if the mirrors are replaced they shall be replaced with mirrors meeting, as a minimum, the requirements of federal motor vehicle safety standard number 111, 49 C.F.R. 571.111.
Every bus shall be equipped with a horn and actuating elements which shall be in such condition as to give an adequate and reliable warning signal.
Any driveshaft extending lengthways under the floor of the passenger compartment shall be protected by means of at least one guard or bracket at that end of the driveshaft which is provided with a sliding connection (spline or other such device) to prevent the whipping of the shaft in the event of failure of the connection or any of its component parts.
A driveshaft contained within a torque tube shall not require any such protective device.
No bus shall be equipped with aisle seats unless such seats are so designed and installed as to automatically fold and leave a clear aisle when they are unoccupied.
Exception: paragraph (W)(2) of this rule shall not apply to a custom-built bus with flooring and/or seating so designed and installed as to prevent self-movement of the seating during normal operations of the bus.
Every bus shall have at least one fire extinguisher that:
Every bus shall have at least one spare fuse or other overload protective device, if the devices used are not of a reset type, for each kind and size used.
Buses required to comply with the rules and regulations of the federal motor carrier administration or the public utilities commission of Ohio shall display their company name on both sides of the bus:
Replaces: 4501-52-03, 4501-52-04
Ohio Admin. Code 4501-52-03
Promulgated Under: 119.03
Statutory Authority: 4513.52
Rule Amplifies: 4513.52
Prior Effective Dates: 02/16/01, 06/18/04, 06/22/06, 04/28/11
R.C. 119.032 review dates: 01/03/2016
Promulgated Under: 119.03
Statutory Authority: R.C. 4513.52
Rule Amplifies: R.C. 4513.52
Prior Effective Dates: 2/16/01, 6/18/04, 6/22/06