System Dynamics Modelling of CAD Impacts

System dynamics (SD) is an approach to modelling complex problems over a specific time period, capturing time delays, non-linearities and feedback loops within a defined model boundary, through a series of coupled differential equations. Building on systems theories within engineering and business management, SD is now widely applied across many sectors, including healthcare, environmental sciences and economics, often to simulate policy scenarios. The development of an SD model requires both qualitative and quantitative approaches, to firstly identify the relevant variables and relationships, and then to build and verify a robust simulation model There has been a rising interest in the application of SD to transportation, specifically around vehicle (and powertrain) uptake, firstly in electro-mobility and more recently in connected and automated driving (CAD). SD is an ideal method for studying factors affecting the uptake of CAD, due to the high levels of pathway uncertainty and interactions that will exist for a disruptive technology in an already complex transportation system.

For a summary on SD see and for contact details for the System Dynamics Society Transportation Special Interest Group see

Figure: Causal loop structure developed at a group model building workshop in Leeds UK, in April 2019 [reference below]

The above figure is from ongoing trilateral work regarding impact assessment:

  • Rakoff, H. E., Smith, S., Innamaa, S., Barnard, Y., Harrison, G., & Shaw, J. (2020, April 27–30). Building feedback into modelling impacts of automated vehicles: Developing a consensus model and quantitative tool. Transport Research Arena 2020, Helsinki, Finland. (Conference cancelled).

Everyone who is working on SD, please let us know (using the feedback form).

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