Traffic safety culture within the safe system: developing a common definition of traffic safety culture

This paper develops a common, theoretically grounded definition of traffic safety culture within a Safe System perspective. It provides the first triangulated, expert-informed, theoretically grounded unified definition of traffic safety culture applicable across actors in the transport system. Despite increasing use of the concept in research and policy, traffic safety culture is defined, measured and used in different ways, which may limit its usefulness for measurement and implementation. To address this gap, the study applies a three-step mixed-methods approach combining systematic literature reviews, two Delphi studies with international experts, and complementary focus group discussions. The literature reviews identified recurring conceptual elements across definitions of organisational safety culture and traffic safety culture, including shared values, beliefs, attitudes, norms, and patterns of behaviour. Two Delphi studies demonstrated strong expert consensus on the importance of these elements for both organisational contexts (e.g., drivers at work) and societal traffic contexts. Focus group discussions further highlighted the need for definitions that are practically applicable, sensitive to social context, and suitable for different actors within the transport system. Based on these findings, the paper proposes a unified definition of traffic safety culture that applies across meaningfully defined groups of actors, including road users, organisations, authorities, and other stakeholders. The definition emphasises shared cultural elements that shape how traffic safety is understood and enacted, while allowing for group-specific aspects in measurement and intervention.