System dynamics is a computational modelling method that is used to understand the dynamic interactions influencing behaviour in complex systems. In this article we argue that the method provides a useful tool for ergonomists wishing to model the behaviour of complex systems. We present a system dynamics model that simulates the behaviour of a drink driving-related trauma system and explore the potential impact of different road safety policy interventions. The model was simulated over thirty-year periods with different policy interventions. The findings suggest that the greatest reduction in drink driving-related trauma can be achieved by policies that integrate standard road safety interventions (e.g. education and enforcement) with interventions designed to address the societal issue of alcohol misuse and addiction. In closing we discuss the potential use of system dynamics modelling in future ergonomics applications and outline its strengths and weaknesses in relation to existing systems ergonomics methods. Practitioner Summary: The outputs of systems ergonomics methods are typically static and cannot simulate behaviour over time. We propose system dynamics as a useful approach for modelling the behaviour of complex systems. Applied to drink driving-related road trauma, the method was able to dynamically model the potential impacts of different policy interventions.
Keywords: System dynamics; computational modelling; drink driving; road safety; systems ergonomics.