Has anyone else tried getting a black cab from LHR away from London? I wanted to get to Slough from LHR but none of the black cabs on the rank would take me (even though there were only about 4 cabs on the rank), but in the end quoted me £60 (for a 5-mile trip!). In the end I found another cab at Departures (who are not allowed to pick up from there) who took me for £30.

Are black cabs allowed to charge a fixed fee like that from LHR? Aren't they obliged to put on the meter for a trip (which would come up to considerably less than £60 for 5 miles?!)