Ozexpat is right about London cabbies. The Black Cab drivers in London have to pass a series of tests at the London Pubic Carrige Office called collectively 'The Knowledge'. They have to know the quickest and/or most direct route bwtween any two points in London within six miles of Charing Cross Train Station. For this they get a green numbered badge and the right to pick up passengers from the street. Passing the knowledge and getting the badge usally takes most people 2 years on average.
The above means that the guy driving your black cab in London is never lost & never doesn't know were you want to go!
Further info
here .
