Ill. Admin. Code tit. 92 § 1550.20
The following words and phrases as used in this Part shall mean -
"Commission": Illinois Commerce Commission.
"Employee": An individual, subject to a collective bargaining agreement, employed for any period in any work for which he is compensated, whether full or part time, whose regular course of employment relates to the maintenance or construction of the railroad physical plant, or to the operation of trains.
"Employer": A common carrier by rail who employs one or more employees.
"Heating facilities": Hot water radiator-type system, or any other generally acceptable form of heating which does not emit nauseous fumes or gases in the vehicle.
"Material": All items that can be lawfully transported by motor vehicles and used in construction and maintenance.
"Motor vehicle": Any vehicle which is self-propelled and designed primarily for highway use, and which may or may not be equipped with retractable flange wheels for operation on railroad tracks.
"Owner": Any person holding legal title to, or having lawful use of the motor vehicle through contract, lease or otherwise.
"Place of employment": All locations where one or more employees are performing the work incident to their employment.
"Rear compartment": A crew cab, which may be a continuation of the driver's cab, providing additional seating capacity, or an auxiliary cab located directly behind the driver's cab.
"Seating facilities": Seats provided for workers other than the driver.
"Tools": Hand and power tools or machines recognized as the type to be used by the craft to which the motor vehicle is assigned.
Ill. Admin. Code tit. 92, § 1550.20