Sensing, learning, inference, and route analysis methods are described that center on the development and use of models that predict road speeds. In use, the system includes a receiver component that receives a traffic system representation, the traffic system representation includes velocities for a plurality of road segments over different contexts. A predictive component analyzes the traffic system representation and automatically assigns velocities to road segments within the traffic system representation, thereby providing more realistic velocities for different contexts where only statistics and/or posted speed limits were available before. The predictive component makes predictions about velocities for road segments at a current time or at specified times in the future by considering available velocity information as well as such information as the properties of roads, geometric relationships among roads of different types, proximal terrain and businesses, and other resources near road segments, and/or contextual information.