Risky road user behaviour is behaviour that adversely affects road safety, such as driving under the influence of alcohol, drugs or medicines, speeding, inappropriate speed, distracted or fatigued driving, red light negation, and failure to use or misuse means of protection (motorcycle or moped helmet, seatbelt).

In the Netherlands, a sustainable road safety approach, in which measures in the fields of Engineering, Education and Enforcement (3Es) are complementary, has been used for decades. Enforcement reduces high-risk road user behaviour and is therefore an important component of this safe system approach.

Sustainable Road Safety implies that the traffic environment is designed to rule out serious crashes and to mitigate the severity of the crashes that do happen. The human dimension is the primary focus: man who is vulnerable, makes mistakes and does not abide by the rules.