1. A method of performing a road network search for vehicle navigation of a vehicle, the method comprising: determining a current location of the vehicle using a navigation system; the navigation system retrieving digital map data in a vicinity of the current location, the digital map data including a set of road segments, each being associated with a hierarchy class and an elevation; the navigation system calculating a road segment-specific weighting factor for road segments included in the set of road segments, the calculation by the navigation system of the weighting factor using a distance between a specific road segment and the current location, and an elevation of the specific road segment, wherein calculating the road segment-specific weighting factor for the specific road segment comprises: the navigation system determining the road segment-specific weighting factor has a same sign of dependency compared to a road segment-specific weighting factor determined for a reference road segment in response to: the specific road segment having a smaller distance to the current location than the reference road segment, and the specific road segment having a larger positive elevation difference with respect to the current location than the reference road segment; the navigation system selectively discarding the road segments from the set of road segments, based on the road segment-specific weighting factor and the associated hierarchy class, to obtain an updated set of road segments; and the navigation system performing the road network search by expanding route links based on the updated set of road segments.