Apprentice taxi drivers learning London's streets on mopeds

Apprentice black cab drivers using mopeds to get to know London streets before they become qualified drivers. Drivers are required to know 320 main routes across London without stopping to look at a map so that they can immediately respond to a passengers request. Even now this is called 'The Knowledge'. Before they could operate drivers were required to study London street maps and drive around London usually on mopeds with maps attached to clipboards. Although now trainee drivers use satellite navigation instead of paper maps they were and still are called 'Knowledge boys'.