Three young men were on their way home from a pig hunting trip near Trangie when their ute veered off the road on Saturday morning.

The absence of skid marks on the road has led police to believe the driver may have fallen asleep.

Fatigue is one of the three biggest killers on NSW roads according to police.

They say being awake for about 17 hours has a similar effect on performance than driving driving with a blood alcohol content of 0.05.

Fatigue-related accidents are also twice as likely to be fatal because drivers who are asleep can't brake.

For those behind the wheel, regular breaks are a must.

There are 10 coffee shops and local businesses in Dubbo that have jumped on board the Free Cuppa for the Driver campaign and it's a service drivers should take advantage of.

All visiting drivers need to do is display their driver's licence to show they're from more than 100 kilometres away.

Narromine mayor Bill McAnally said there would be some devastated parents having to mourn the loss of three young men.

But as well as the three Trangie fatalities there were three other lives lost and 64 people injured on NSW roads at the weekend.

Those families and friends will also be suffering from their losses.

As police have said, it is up to those behind the wheel to ensure the safety of themselves and their passengers.

How many incidents could be prevented with a break and a free cuppa?