• Nodes. These are reflected in the centrality of urban activities, which can be related to
the spatial accumulation of economic activities or to the accessibility to the transport
system. Terminals, such as ports, railyards and stations, and airports, are important
nodes around which activities agglomerate at the local or regional level. Nodes have
a hierarchy related to their importance and contribution to urban functions, such as
production, management, retailing and distribution.