[boygobbo]

The speed limit is a bit of a red herring. The average speed of traffic in central London is about 9 miles/hour & inner London about 12. The average speed in the suburbs (outer London) is about 20 mph, even though the speed limit is 30 mph.

Average traffic speed in London: https://www.london.gov.uk/questions/sites/default/files/0832...

London speed limits: https://content.tfl.gov.uk/london-digital-speed-limit-map.pd...