Patent ID: 8457890

Claim:
A method for generating a digital roadmap that can be stored on an electronic storage medium and in which the road network of a geographical area is specified by a multitude of data sets, comprising the following method steps: a) loading an original database, in which the road network of the geographical area is specified by a multitude of data sets, into an electronic analyzing device, wherein road data sets are contained in the original database, and wherein each road data set is representative of a road element as a sequence of n reference points, and wherein each road data set comprises at least two (n=2) reference points, b) selecting a road data set from the original database, c) determining a first road start angle (α) that is enclosed between a road start vector and a reference direction vector, wherein the road start vector extends between the first reference point of the road element and the second reference point of the road element or in the opposite direction, and wherein the reference direction vector extends through the first or the second reference point of the road element in a predetermined reference direction, d) determining a road end angle (β) that is enclosed between a road end vector and a reference direction vector, wherein the road end vector extends between the ultimate reference point of the road element and the penultimate reference point of the road element or in the opposite direction, and wherein the reference direction vector extends through the ultimate or the penultimate reference point of the road element in the predetermined reference direction, e) storing the road start angle (α) and the road end angle (β) or two angular values derived from the road start angle (α) and the road end angle (β) additionally to the road data set in a resultant database, f) repeating steps b) to e) for a multitude of road data sets; wherein the orientation of the road start angle (α) and the road end angle (β) that is dependent on the direction of travel along a route is ascertained and stored in the resultant database; and wherein the orientation of the road start angle (α) and the road end angle (β) is uniformly ascertained in a clockwise direction or in an anti-clockwise direction.