Evaluating the effects on road safety of the "Speak out !" campaign in Sogn og Fjordane county, Norway : an illustration of the logic of causal inference in road safety studies.

The high road accident rate of teenagers is a cause for concern in many motorised countries. Traditional driver training and public information campaigns have not been very successful in reducing accident rates. The county of Sogn og Fjordane, a mainly rural county on the West coast of Norway, decided to try a new type of road safety campaign in order to reduce the number of injury accidents involving teenagers, particularly those between 16 and 19. The "Speak out!" campaign was started in 1993 and has been going on every year since then. It consists of two main components: information and enforcement. (A)