Source: adapted from OECD (2009) “Applications of Complexity Science for Public Policy: New Tools for Finding Unanticipated Consequences and Unrealized Opportunities”, Global Science Forum.
Transportation, as a complex system, shares many of its characteristics, including:
- Adaptability. A standard characteristic best reflected by the concept of competition where transport firms adapt to their competitors and other socioeconomic changes (demand). Investment in new and expanded infrastructure is also an adaptation strategy followed by corporations and governments.
- Self-organization. Routing within a transport network represents the characteristic of self-organization as the intermodal sequence is the outcome of the consideration of all the respective advantages of modes and terminals. Supply chain management is also illustrative of self-organization as sourcing and distribution strategies change to reflect complex input and distribution costs.
- Stability. Represent the stable components of the transport system having a long term influence on the nature and extent of flows. Land use is a particularly stable component of spatial interactions since its characteristics are slow to change. The same applies to transport terminals that are long term locations in the convergence of flows.
- Cumulative. Congestion is a good example of a non-linear characteristic of transportation as each degree of additional congestion results in exponential delays. Various disruptions over transport networks are also an instance of non-linearity as a relatively simple event such as the shutting down of an airport hub (e.g. a snowstorm) will trigger disproportionate disruptions through the whole network.
- Phase transition. There are several events that may trigger substantial changes in transport systems. One type relates to technological (or technical) innovations that historically have been paradigm shifts for the transportation system. For instance, containerization is linked to entirely new flow patterns, modes, and terminals; it created an entirely new transport system. Issues related to carbon emissions are also considered to be a highly susceptible factor triggering a phase transition for 21st-century transport systems.