​​Driving a motor vehicle requires constant attention, good judgement, appropriate responsiveness and reasonable physical capability.
People who drive (or are seeking to drive) heavy vehicles, public passenger vehicles or vehicles carrying bulk dangerous goods must meet the commercial vehicle driver standards. These are more stringent than the private standards, reflecting the increased risk associated with accidents involving such vehicles. This includes a requirement to meet a hearing standard making it advantageous to have ready access to audiometry where there is doubt about the person meeting the standard clinically.
 
In NSW, the frequency of these Medicals varies:

Class MC (road trains)
On initial application, at age 21, every 10 years to age 40, every 5 years to age 60, every 2 years to age 70, then annually 

Public Passenger vehicles (buses, taxis)
On initial application, every 3 years to age 60, then annually

Dangerous Goods Drivers
On initial application, then every 5 years

All other commercial drivers
Annually from age 75

Industry schemes such as TruckSafe and NHVAS require more frequent medical assessments


The Austroads medical standards to which commercial drivers are assessed can be accessed online