Source: adapted from Notteboom, T. and J-P Rodrigue (2007) "Re-assessing Port-Hinterland Relationships in the Context of Global Supply Chains", in J. Wang et al. (eds) Inserting Port-Cities in Global Supply Chains, London: Ashgate.
- Geographical location (first layer). Locations are relative and define the market potential through their function of being an origin, destination or an intermediary for transport flows. Thanks to an excellent location and economies of scale and density, many transport nodes such as airports, seaports, railway stations or intermodal terminals serve as important consolidation and bundling points in transport systems. By offering a good intermediate location, for example near the main maritime routes and / or near production and consumption centers, transport nodes can adopt an important turntable function in national or international transport service networks, thereby attracting not only destination traffic but also substantial transit flows.
- Transport infrastructure (second layer). A favorable geographical location is meaningless if it is not valorized by means of the provision of efficient infrastructures. The infrastructural layer involves the provision and exploitation of basic infrastructure for both links and nodes in the transport system. The development of intermodalism has made particularly relevant the connectedness of infrastructures.
- Transport service operation (third layer). The transportation of passengers or freight between two places involves the use of a complex mix of transport infrastructures and transport services. Passenger and goods do not always follow the shortest path between origins and destinations, but instead pass via intermediate nodes in the transport system. This takes plae in view of switching to another transport mode (e.g. transfer from rail to air in an airport) or to shift between small units to larger units of the same transport mode (e.g. transfer from a shorthaul intra-regional flight to a connecting longhaul flight or the transfer in a transshipment hub from a feeder vessel to a deepsea post-panamax container vessel).
- Transport chain organization (fourth layer). The flow of passengers or freight through a multimodal transport system requires the involvement of actors who have the managerial capabilities to design a seamless and efficient transport chain. Logistics service providers and freight forwarders have developed a specialization in this area, supported by a good market knowledge and powerful information and communication systems. At the logistical layer shippers, freight forwarders, logistics service providers and other market parties design the routing solutions that best fit the requirements of the supply chains they are dealing with. The decision-making at the level of the logistics layers is mainly oriented towards the design of the distribution network and the choice of the transport route and associated transport modes and nodes.