If you have to drive in London, you will not be surprised that it has the slowest-moving traffic in Europe at just 12 mph. If you were delivering in Hamburg, however, you could zip through the streets at more than 50. Manchester is positively speedy with a 19mph average and in Newcastle Upon Tyne races ahead at 26mpg, according to a new survey by keepmoving.co.uk Still, there is a bright side. You will never be snapped by a speed camera if you keep to the average London speed. Meanwhile London Mayor Ken Livingstone plans to remove speed bumps (hurray) and replace them with 20mph zones policed by wireless average speed traffic camera. Still again at 12 with the average speed of just 12 miles per hour in London, no car will be caught as they will all be less than 20 mph.
Incidentally average speed cameras are now the big new thing with lots of new cameras springing up. You can see what they look like and where they are at Speed Cameras UK web site.

The keepmoving.co.uk web site is also worth visiting.