If you’re on a long drive on your own, or with family or friends, always stop if you feel sleepy. Crashes happen easily when you’re tired.
Before a long drive, get plenty of rest. Share the driving if you can. If possible, drive during the day. It’s less tiring.
Signs of tiredness include:
Get out of the car, stretch, have some food or a drink. This will help for a short time, but you'll probably feel tired again soon. The best cure for sleepiness is sleep.
Don’t rush, and take plenty of breaks.