A trail management system for a transport network comprises a database storing data describing each of a plurality of actual and intended/planned trails within a network. Each trail is described in terms of a state model, in which the trail is recorded as being in one of a plurality of stable states, e.g. ready for service, not ready for service, existing in the network but not fully recorded in the network management system, or assigned for deletion from the network. The trail data is modified by a set of automatic processes, by means of which a trail data may transition between stable states. Each trail data may adopt one of a plurality of sub-states, e.g. fully provisioned, incomplete, in conflict with another trail, inconsistent with another trail, unprovisioned, or unsupported by network resources. The network management system learns of actual existing trails within the network and checks for consistency of actual trails with stored trail data.