Public communication and education are often thought to be the (only) methods to influence behaviour. And because behaviour is a factor in many crashes, it is regularly concluded that crashes can be prevented with these methods. But they are certainly not the only, or most effective, measures to influence behaviour. Human behaviour is complex and difficult to change, even if people want to. Measures that do not require people to decide on their road user behaviour themselves, such as vehicle measures or infrastructure measures, are therefore more effective. Like traffic enforcement, they are aimed at preventing undesirable behaviour.
Almost all road crashes can be traced to one common factor: human behaviour. As early as the 1970s, it became clear that road user behaviour is an important factor in more than 90% of crashes [66]. But behaviour does not come out of the blue, it is affected by other factors, such as infrastructure, behaviour of other road users, vehicle characteristics and weather conditions.
Indeed, road user behaviour can also be ‘guided’ with good road design (such as roundabouts) and smart vehicle systems (such as intelligent speed assistance, ISA), making it almost impossible to drive faster than the limit. Traffic enforcement also aims to change road user behaviour. That is why it is particularly important to focus on a mix of measures; i.e. measures that do not require people to decide on their road user behaviour themselves - such as vehicle measures or infrastructure measures - combined with supporting measures that explain, set standards and enforce those standards - such as education, public communication, and enforcement (see Table 2, taken from [65]).
Table 2. Expected effects, reach, costs and deciding parties (influence) of the three E's (Engineering, Education and Enforcement) [65].
