Do safety measures really work? An examination of risk homoeostasis theory

The claim that safety measures in general fail to work is examined. This claim is seen as consistent with risk homoeostasis theory which proposes that following the introduction of a safety measure drivers compensate in such a way as to bring the accident involvement back to the preceding level. The validity of risk homoeostasis theory rests on several assumptions: (i) people have a simple and straightforward representation of accident risk, (ii) people can detect all changes in this accident risk, (iii) people can, over time, completely compensate for changes in accident risk and (iv) people cannot be discouraged or prevented from compensating for changes in accident risk. Each of these assumptions is examined