US Patent 8452529 Adaptive navigation system for estimating travel times

An estimated travel time for a route generated by a navigation system can be modified using a route-specific, custom travel factor computed from data collected by the navigation system while the user is traveling the route. In one aspect, the data can be stored in a local or remote database accessible by the navigation system. The data can be used to classify routes so that custom travel factors computed for a route in a given class can be used to estimate travel times for other routes in the same class. In another aspect, the classified custom travel factors can be shared with other users.