Rule 91
Driving when you are tired greatly increases your risk of collision. To minimise this risk make sure you are fit to drive. Do not begin a journey if you are tired. Get sufficient sleep before embarking on a long journey avoid undertaking long journeys between midnight and 6 am, when natural alertness is at a minimum plan your journey to take sufficient breaks. A minimum break of at least 15 minutes after every two hours of driving is recommended if you feel sleepy, stop in a safe place. Do not stop in an emergency area or on a hard shoulder of a motorway (see Rule 262 for guidance on places to take a break when travelling on motorways).