Fatigue (being tired, weary, exhausted or jetlagged) slows your reflexes and affects your ability to concentrate and make good decisions.

What can you do to reduce the risk?

Take a power nap
Try to avoid driving when you would normally be sleeping
Plan your journey to take a break every 2 hours
Get a good night's sleep before driving on any long distance journey
Share the driving
Snack on light, fresh food
Avoid driving after long-haul flights, it can take a few days to fully recover from jet lag
Fatigue is a physiological condition that is present long before a driver dozes off behind the wheel