Abstract: Road data is stored in hierarchically organized levels. A lower level has detailed representations of road links and junctions. At a globalized level an abstracted representation is derived: a set of elementary junctions is joined to a complex junction on the basis of predetermined coherencies among the elements of the set. This repeats until all complex junctions have been found. All external road links between a border element of a particular set and any element of a particular neighboring set are detected, including allowed traffic directions on the external road links. The links are collected to a single complex road link while mapping the allowed traffic directions thereon. This repeats until all complex road links have been found. Remaining elementary and complex junction are represented by a respective single node. Also, each remaining elementary and complex road link is represented by a single higher level road link.