What does road 'fatigue' mean in the context of road safety in Tasmania, and why is it dangerous?

1. Fatigue only refers to tyre wear and does not affect the driver
2. Driver fatigue slows reaction time, reduces awareness, and can cause a driver to fall asleep at the wheel — it is one of the top five crash causes
3. Fatigue only becomes dangerous after 12 consecutive hours of driving
4. Fatigue is less dangerous than speeding because a tired driver still follows road rules