As defined by page 45 of the New South Wales Road Users' Handbook, the early warning signs of fatigue are:

  • Yawning.
  • Poor concentration.
  • Tired or sore eyes.
  • Restlessness.
  • Drowsiness.
  • Slow reactions.
  • Boredom.
  • Feeling irritable.
  • Making fewer and larger steering corrections.
  • Missing road signs.
  • Having difficulty staying in the lane.

I'd add heat. A lot of people I talk to claim to feel cold when fatigued; for some reason I feel as though I'm burning up. I also feel overconfident in my joke telling abilities.

And something I didn't know:

During peak holiday travel periods, such as Christmas, Easter and holiday long weekends, almost 100 Community Driver Reviver sites operate throughout NSW. These are places to take a break during a long journey and have a free cup of tea or coffee and a snack. Local volunteers are on hand to offer advice about road conditions.

That's really cool.