This manual provides the technical details of a model that was constructed to explore greenhouse gas mitigation strategies in the freight transport sector in an integrated fashion, and understand what the impact of these strategies on the wider economy and environment will be. It forms part of a larger study commissioned by WWF South Africa on low carbon frameworks for transport, and builds on previous work conducted by the authors for WWF on low carbon planning (WWF, 2011) in which a quantitative modelling framework to support national low carbon planning was proposed.
This framework had at its core a system dynamics model developed through a stakeholder engagement process known as “mediated modelling”. System dynamics allows for the exploration of the evolution of a complex system over time, through consideration of the feedback loops and dynamic behaviour of the system. This approach is useful in that it overcomes some of the problems inherent in linear thinking, and compartmentalised and non-participatory decision making. Similar international transport system dynamics modelling was conducted by the French Ministry of Transport (Salini & Karsky, 2003) and for the EU15 countries via the Assessment of Transport Strategies (ASTRA) model (IWW, 2000).
The manual details the methodology used in the development of the model, the model structure, all the data inputs and assumptions, and results from a sensitivity analysis on the model.