Driving for any length of time can become boring, leading to inattention, drowsiness, and accidents.
Having a passenger in the car who can engage you in conversation, and monitor your wakefulness helps keep you alert, but failing that – listening to the radio, opening the window to let cool air on your face, and frequent rest breaks when you ‘re feeling tired are recommended by motoring organisations and the police.
What they don’t recommend is driving with a vibrator up your arse . . .