In the network of DC downtown, a zone in middle is lost. Maybe that is caused by no boundary node in that grid. But if there is any POI node, it should be a zone to generate travel demand. Hope the zones could cover all nodes. In other word, each node should be assigned to a unique zone.

In the network of DC downtown, a zone in middle is lost. Maybe that is caused by no boundary node in that grid. But if there is any POI node, it should be a zone to generate travel demand. Hope the zones could cover all nodes. In other word, each node should be assigned to a unique zone.
