Looking for data sources for real road speeds

Waze is one route - but uses Ordnance Survey data (at cost) in the UK.

http://www.waze.com/wiki/index.php/United_Kingdom

http://www.waze.com/livemap/ (US only)

Sabre Roads is another project (waze links to this)

"perhaps the most complete archive of information on the British and Irish road network"

http://www.sabre-roads.org.uk/wiki/index.php?title=Main_Page

Trafficmaster (at cost)

Those blue long cameras mounted on blue poles is your best source: There are 5,200 cameras - they monitor congestion live http://www.trafficmaster.co.uk/content/1/60/real-time-traffic-information.html

(you will need an account and they will charge you to access to the live data - [email protected])