The selection of a transport route can be made by three actors:
- Type I. The users of passenger transport or the owners of the cargo select the route. This is common for private transport, where each driver selects a route, which can be modified in real time. Own-account freight transport also involves route selection by the cargo owner through its transport assets. Routing is the outcome of a large number of individual decisions seeking to optimize their own path considering the current capacity and congestion level of the network.
- Type II. An actor acting on behalf of passengers or cargo owners is responsible for allocating transport resources and finding a route satisfying their requirements. For instance, a taxi will select a route on behalf of its customers and a chartered flight can be booked on behalf of a tour company. A trucking company could carry cargo through routes assigned by a freight forwarder or any agent acting on behalf of the cargo owner.
- Type III. The carrier designs a service network that tries to maximize the use of its transport assets and make available this capacity on the market. This is particularly the case for air and maritime transportation where routes are set by carriers, subsequently booking passengers and cargo on these routes. Public transit systems and railways are also operating in such a fashion but with less flexibility as routes are bound to fixed assets.