A system and method are provided for forming a map database with attributed data which represents roadways attributed as no-outlet or circular segments. The method includes identifying a segment from a first node to a second node, where the second node is connected to an isolated portion of a road network. The method further includes storing a data attribute into the map database that represents the segment as a road that connects the road network at the first node to the isolated portion of the road network at the second node. The data attribute may represent the segment as a no-outlet segment or a circular segment. A no-outlet segment represents a roadway or portion of a roadway that terminates or returns back to the roadway or portion thereof. A circular segment represents a roadway or portion of a roadway that intersects with a geographic feature, such as a road, and where the roadway or portion thereof leads back to the same geographic feature. The attributed segment may provide directional information to determine the directional nature of the no-outlet or circular segment. The map database with attributed data is particularly useful for route calculation in navigation systems and related applications.