The service comes from itmc... I dont think it's a deliver issue but more an editorial problem. The data they supply comes from various sources .. not just road sensors. I did ask them once why they never show any of the scheduled road closures such as Marathon etc.. and one of their guys was going to call me but I never heard anything from them.

For some reason they seemingly cant be bothered to service central london. The also have data from Floating Vehicle Data systems which are carried by AA, Eddie Stobart & National Express but I'm not sure if they use this for real-time applications or historical traffic flow data.