Update: I had scheduled this post for next week, but apparently, Data.gov.uk launched today. The site isn't loading for me right now though. I guess they weren't prepared for traffic.
Data.gov, a catalog of US data, launched last year. Now it's the UK's turn. Well, not yet. But soon. Data.gov.uk is still under lock and key, but it has granted access to some developers. Ito Labs, the group behind mapping a year of OpenStreetMap edits posted screenshots of their maps that show vehicle counts (above).
Here are some comparison maps between 2001 and 2008, by vehicle type.