System and method for using a map database with attributed no-outlet and circular segments

A method for a route calculation search performed by a route calculation program, the method comprising:

• retrieving a data structure in a map database that represents a successor segment with a first node and a second node;
• identifying an attribute in the data structure that identifies the successor segment as a segment that connects an isolated portion of a road network at the second node thereof to a non-isolated portion of the road network at the first node thereof;
• and
• refraining from evaluating the isolated portion of the road network if the route calculation search retrieved the successor segment at the first node.

In a navigation system in which geographic data are used by an end user's platform to provide navigation related features to an end user, a method comprising:

• using data structures in the end user's computing platform, wherein each data structure includes:
• a) fields with data that represent a segment of a road in a road network;
• and
• b) a data attribute in one of the fields that identifies the segment as one that connects a non-isolated portion of the road network with an isolated portion of the road network;
• wherein the end user's computing platform uses the attribute to determine whether to evaluate segments in the isolated portion of the road network for inclusion in a calculated route.

A navigation system comprising:

• a map database for storing attributes that characterize segments of roads, including attributes that indicate whether a segment leads to an isolated portion of the road network;
• and
• a navigation program for calculating a route between a first location on the road network represented by the map database and a second location on the road network represented by the map database;
• wherein the navigation program uses the attributes to determine whether to explore an isolated portion of the road network.