Source: Adapted from U. Blum and L. Dudley (2001) Report of the 109 round table on transport economics, Transport and Economic Development, European Conference of Transport Ministers.
Transportation networks are designed to offer a level of service which is related to their structure. Conceptually, three basic network structures can be designed to link the same locations:
- Centralized. One center has high accessibility and thus represents the dominant element of the network and the spatial structure it supports. This is the common characteristic of hub and spoke networks.
- Decentralized. Although the center is still the point of highest accessibility, the network is structured so that sub-centers have also significant levels of accessibility.
- Distributed. No center has a level of accessibility significantly different from the others, which implies a high connectivity levels and redundancy.