Teeteringhead
Accidents caused by fatigue do occur but aren’t that common up our way.
Alcohol, stupidity and poor road surfaces are greater contributors.
When we transitioned from open speed limits to 130km/h, fatigue did become a much greater problem for me. The old system had you driving to the conditions, which meant paying attention. The newer arrangements saw you setting cruise control and fighting boredom (until you hit that section that should have been re-signed as 60 km/h. ). Darwin to Alice Springs also went from being a comfortable 12 hour day to 15 hours if lucky.
Thinking on it, perhaps the accident toll is kept down by the amount of time you have to spend stuck behind caravans doing 50 km/h under the speed limit.