How can we discover what works in the prevention of road traffic crashes

Each year worldwide more than a million people die and some ten million people sustain permanent disabilities in road traffic crashes [1]. For people aged under 35 years, road traffic crashes are now the leading cause of death and disablement. Nevertheless, the epidemic of road traffic crashes is only beginning. It is estimated that by the year 2020 road traffic crashes will be the third leading cause of disability-adjusted life years lost worldwide, and the second leading cause in developing countries [2].