Seriously
Touchy subject for me.
I have lost 2 workmates over the years due to falling asleep while driving, luckily they only killed themselves.
I have seen the results of more than a few crashes from fatigued drivers.
When I discovered that I was prone to sleep apnoea - I voluntarily handed in my truck license, as well as my permits for transporting Dangerous Goods and Explosives.
There is no way I was going to take the risk of wiping out someone else [let alone possibly removing a small town from the map]
If you are tired - pull over, park up and have a snooze.
Anything less is criminal negligence as far as I am concerned.
stephen