Dehydration of routes enables transmitting a description of a route requiring much less space than full specification of the route. A series of “breadcrumbs” and hints are used for dehydration. A breadcrumb includes coordinates of a point, a heading at which the route enters the breadcrumb, and a heading at which the route leaves the breadcrumb. A dehydration module places a breadcrumb at the location marking the beginning of the route, and having a leaving heading identifying the link in the original route. The node at the end of each link in the original route is examined. If the link leaving the node is the most parallel link to the link entering the node, nothing is added to the dehydrated route. If not, a breadcrumb is added to the dehydrated route, specifying the coordinates of the point, the entering heading of the breadcrumb and the leaving heading of the breadcrumb.