Transport Supply and Demand
Transport supply is generally expressed by Aij; the transport supply between location i and j. Indirectly it combines modal supply, the capacity of a mode to support traffic, and intermodal supply, the capacity to transship traffic from one mode to the other. Transport demand is represented by Tij, which expresses the transport demand between location i and j. The potential transport demand would be the amount of traffic if transport costs were negligible. The realized transport demand, a subset of the potential transport demand, is the traffic that actually takes place, namely in view of costs between the origins and the destinations.