Road anger expression-Changes over time and attributed reasons

Based on the results from three independent surveys conducted in Denmark in 2005, 2008 and 2016, this paper provides an overview of the development of road anger expression in general and in demographic sub-groups of road users. In addition, it investigates how people explain own and other people's road anger expression and if attributed reasons are related to demographic factors and level of anger expression measured based on the short form of the driving anger expression inventory (DAX-short). From 2005 to 2016 the percentage of people involved in anger expression incidents increased particularly in the densely populated Capital Region of Denmark. The increase was most pronounced for "yelling" and "threatening". Men were more often involved than women both as aggressor and as victim, but the gender difference decreased from 2008 to 2016. Generally, own anger expression was more often explained with getting frightened (non-hostile attribution), while anger expression by other road users was more often explained by not being able to control own anger or by wanting to show that one made a mistake (hostile attribution). However, people scoring high in aggressive anger expression often explained own anger expression by "not being able to control anger", thereby indicating self-reflection and a potential for behavioural change. Behavioural reactions to being frightened are to some extend mistakenly interpreted as expressions of anger by other road users. Results indicate that cognitive and behavioural interventions, possibly as part of the driver education, are relevant to reduce aggressive anger expression in traffic.