Transport for London's taxi driver handbook of 29 July 2025 tells London black cab drivers not to start driving, and not to take a fare, if they already feel tired. A self-employed driver can choose the hours they work, and there are no rules that limit the number of hours in a day or a week. Regular breaks and regular days off still matter, because driving when tired greatly increases the risk of collisions.
Tiredness can have a similar effect to drinking alcohol and can result in death or serious injury. The advice is to plan regular breaks, to get enough sleep before work, and to avoid a heavy meal before driving. A 15-minute break is suggested for every two hours of driving, with a stop as soon as tiredness begins, and a nap of around 15 to 20 minutes when necessary. Caffeine does not last long, and when it wears off a driver may feel more fatigued.
Late night and an early start
The pattern of work can itself cause fatigue, including a switch from days to nights. A long period without sleep, or only a short sleep before going to work, can increase the risk. The risk may also be higher late at night or early in the morning, when people tend to notice things more slowly.
Private hire
London private hire drivers are given a shorter warning in the private hire driver handbook of 30 September 2021. Tiredness can have a similar effect to alcohol and can result in death or serious injury. The handbook asks those drivers to plan regular breaks and not to begin a journey if they are already tired.