The long term effect of seat belt legislation on road user injury patterns.

A first assessment of the use of Scottish linked transport-health data was made in an earlier report (Tunbridge, 1987). The current investigation has sought to gain more insight into the nature and severity of injury, by looking at injury patterns before and after seat belt legislation. This study was designed with three principal objectives: (i) to consider car occupant casualty rates and injury patterns for an extended period before and after seat belt legislation (using an independent set of hospital data), and to compare the findings with an earlier study (Rutherford, 1985); (ii) to use the same dataset to test new hypotheses based on unconfirmed results from the previous study; (iii) to assess the effects of the legislation on casualty rates among road users other than car occupants. Among the conclusions, it was found that the principal benefits of seat belt legislation, e.g. substantial reductions in serious injuries, have been sustained for the three years following its introduction. Further benefits to car occupants, e.g. reductions in major leg fractures and abdominal injuries, have also been confirmed. Hypotheses concerning casualties among other road users are also propounded and tested. (A)