The first trip after a cabbie passes his Knowledge test is free to the customer. I’ve never found one yet. Cabbies have to learn about public buildings as well as roads, and remember roads for their test knowledge with mnemonics. Cutting through Covent Garden is ‘Wet T-Shirts’ – Wellington, Tavistock, Southampton, Henrietta.
Many cabbies have slang for different bits of London. For example, ‘Hot & Cold Corner’ is by the Royal Geographical Society’s statues of David Livingstone and Ernest Shackleton
A cabbie expression is ‘on the cotton’, which means you decide on a route, draw it on a map and get a piece of cotton to see how straight your line was. If you were as close as you could be, you’re ‘on the cotton’.
Not many tourists know that some London cabbies can be hired as guides for the day at a flat rate.