A method of generating a routing policy from an origin to a destination through a navigable network, the navigable network being represented by an electronic map comprising a plurality of segments representing navigable segments of the navigable network, each segment having associated therewith data indicative of an expected travel time along the segment. The expected travel times are used for respective segments of the electronic map to determine a route from the origin to the destination that has a shortest expected journey time using a deterministic routing algorithm. A stochastic routing algorithm is then used to generate a routing policy that maximizes the probability of arriving at the destination within a time budget from leaving the origin, wherein the time budget is based at least on said determined shortest expected journey time. A route from the origin to the destination can then be generated by applying the routing policy to a scenario in which each segment is transited in a time based on the data indicative of the expected travel time associated with the respective segment.