Highway Code: fitness to drive
You can drive just when your health condition is appropriate for driving. Driving when you are tired increases your risk of collision. To get rid of this unneeded risk follow the following principles: Before long journey get a good night's sleep. If possible do not plan long journeys between 12:00 am and 6:00 am, because this is a time when naturally people's alertness is at minimums. Plan enough time for your journey for an opportunity to take breaks if such need occurs. If there is need to stop for rest or sleep, stop in a safe place. Don't stop on motorway or highway.