A search engine of flexibly-defined paths applicable to the search of transportation-related routes.A location system within a spatial subsystem (059) is used to define nodes or waypoint locations (031), and flexible nodes by defining loci (030) in the proximity of the nodes (031), which represent operational spaces.Flexible paths (FIG. 4B) are defined by elements comprising these nodes or waypoints (031) and loci or associated spaces (030), as well as with other constraints. These are structured and organized into spatially-related database and indexes (5106, 5102, 5102) with the aid of a spatial subsystem (059), typically a G.I.S.The system can search for paths or combinations of paths (300 to 310) representing service providers, capable of fulfilling requirements specified by a service user.Reservations are enabled through a central reservation system managing three-dimensional space and constraints comprising a dimensional subsystem (061).The flexible path concept is extendible to networks with flexible nodes where similar analysis for connections or routing can be made.