This is pretty impressive. In 2012 I worked in a research project where we did something similar but for a smaller area (vienna). See http://meineradspur.at/ ht

This is pretty impressive. In 2012 I worked in a research project where we did something similar but for a smaller area (vienna). See http://meineradspur.at/ http://meineradspur.at/ including color coded information about the speed of the cyclists.