The Arrive Alive Website received the Following Question:

Speed limits: Message
The number of trucks over 9 tons ignoring the 80kph limit is scary. More so is the fact that, traffic officers I have spoken to, say that speed checking in a say 120kph zone does not differentiate between trucks and other vehicles.

REALLY? Are these trucks also not checked for exceeding 80kph in the ‘time over distance’ checks? Please clarify this.
Answer:

They most definitely are! For more info, view:

Average Speed Aver Distance Traffic Enforcement