I have always thought it would be clever to use data from movement of cell phones to monitor traffic, vs the road sensor and camera and fleet based methods used by MSN Traffic and TMC Traffic.
Sure enough…there appears to be a company trying this, but from the web site and press releases, not much progress.
Does anyone know more about whether this approach is being considered/used by the big GPS traffic services (MSN Traffic and TMC/NavTec) ?