London’s bus routes first started being numbered in ... Double-decker bus routes were numbered 1 to 199, single-decker routes from 200 and trolleybuses from 500. These days numbers 1 to 599 ...

Millions of people use the Tube, London Buses and the Overground around the clock. When travelling in a hurry or just bleary-eyed after a bad night of sleep, it is too easy to leave something behind.