What is an AZ (or A-Z) driver?
The term is something specific to Ontario. The "A" in AZ stands for the class of driver's license required to
operate tractor trailer combinations. Other provinces may refer to that particular class of license as a Class
"1", but they mean the same thing.
The "Z" in AZ represents an endorsement commercial drivers must have in Ontario to certify that they are trained in the function and operation of an air brake system. The "Z" endorsement is not limited to tractor trailer drivers. The driver of any vehicle equipped with air brakes, including buses and straight trucks, must hold a "Z" endorsement. Again, as with the Class "A" license, different provinces have different designations for the endorsement. In the U.S., the Commercial Driver's License (CDL) test includes the appropriate air brake questions, so the extra endorsement isn't necessary.