Measuring the Benefits of Transport Safety

Two inescapable facts confront those concerned to determine the appropriate level of provision of safety on any particular transport mode. First, safety is typically not a free good, and second, society’s resources are not limitless. This means that a responsible decision for or against any proposed transport safety improvement will require a judgement as to whether or not the reduction in risk afforded by the improvement is large enough to justify its cost of provision. This then raises the question of how such a judgement might be made. At the intuitive level, most of us would no doubt agree that a safety improvement which would cost just a few thousand pounds, and which could be expected to prevent several fatalities, would be well-warranted. Equally, most people would have little hesitation in deciding against a proposal that would cost several millions of pounds but which would, at best, prevent only one or two minor injuries. In less extreme cases, however, matters are not quite so straightforward.