A transport network, or transportation network is a realisation of a spatial network, describing a structure which permits either vehicular movement or flow of some commodity. Examples are network of roads and streets, railways, pipes, aqueducts, and power lines. One can distinguish land, sea and air transportation networks.
Transport network analysis is used to determine the flow of vehicles (or people) through a transport network, typically using mathematical graph theory. It may combine different modes of transport, for example, walking and car, to model multi-modal journeys. Transport network analysis is within the field of transport engineering.