If the `man from Mars' were to take a look at the man/vehicle/ environment system, his verdict might be that the system is expensive, inefficient, dangerous and damaging to the planet, and that the term `civilisation' is hardly justified in this respect. If we are to move from intervention on the basis of received wisdom to rational and informed assessment of the most appropriate and effective measures, better knowledge and understanding of the operation of the system is essential. If the risk homeostasis theory is accepted, all measures are open to doubt. The concept of safety can only be defined and measured in terms of the absence of some other opposing quality - safety can only be measured in terms of unsafety, i.e. accidents. In future, major improvements in safety will only come about through major changes in society. For the paper by Johansson see C 6519.
Abstract