Well, the unique data needed is "speed-limit" of each street, with that could be knowing the traffic in whatever street; basically is comparing the speed current with speed of gps. As an examp: If I driving in a street where the speed-limit is 45mph but I driving 15mph for whatever reason then valhalla could suspecting a traffic based on data of "speed-limit/speed-gps/time-running-in-15mph" then new route could be generated. But this way perhaps need constant monitoring. : ) But even this feature could be implemented too without any of data, by just applying the "Logistic". Thanks