9. The computer-implemented method of claim 8 , the method further comprising: determining, via the one or more processors, a driver ID for the current driving session; and restricting, via the one or more processors, the plurality of conditional variant models associated with the target attribute to include only conditional variant models associated with the driver ID.
8. A computer-implemented method to be implemented via one or more processors, for generating directions for use in navigation during a current driving session, comprising: receiving a target destination; generating, via the one or more processors, at least one candidate route; probabilistically determining, via the one or more processors, that one of a plurality of conditional variant models associated with a target attribute corresponds to a condition of the target attribute, the plurality of conditional variant models learned from previous user driving sessions; scoring, via the one or more processors, the at least one candidate route using the determined conditional variant model; providing a scored route to a user; detecting, via the one or more processors, a change in the condition of the target attribute, wherein detecting a change in the condition of the target attribute comprises: recomputing probabilities for the conditional variant models associated with the target attribute periodically during the current driving session using subsequently observed data of the current driving session; and probabilistically determining that a second conditional variant model currently corresponds to the condition of the target attribute; and providing an altered route to the user based on the detected change.