1. A method for determining a recommended route from an origin to a destination using a computer-implemented routing system, the method comprising: receiving a request for a route; accessing, from within a computer-accessible memory and before determination of the route, mapping information that represents a network of roads; accessing, before determination of the route, link information which includes entries identifying directed links included in a routing graph, each entry indicating a starting node of the directed link, an ending node of the directed link, a direction of travel associated with the directed link, and an indication of cost associated with traversing along the direction of travel of the directed link, the link information including: a first directed link connecting a first node to a second node in a direction from the first node to the second node, and a second directed link connecting the first node to the second node in a direction from the second node to the first node; identifying, based on the accessed link information and before determination of the route, a subset of the directed links to be included in the a route from the origin to the destination along roads within the network of roads, the subset including either the first directed link in the direction from the first node to the second node or the second directed link in the direction from the second node to the first node, but not both the first and the second directed links; and determining a recommended route that specifies driving maneuvers corresponding to the identified subset of directed links to traverse a path from the origin to the destination along roads within the network of roads.