Two field accident databases are examined to review and contrast some of the characteristics of side impact collisions in the US and Europe. NASS and CCIS weighted data files illustrate the importance of the characteristics of the striking object not being another car. In the US data pickup trucks (including SUVs and minivans) are important whilst in UK side impact crashes, off road fixed object collisions feature frequently. Neither of the current full scale mobile barrier test requirements fully address the reality of current moderate (AIS 2) or serious to fatal (AIS 3 – 6) side impact collisions. Delta – V distributions from both databases give indications of the conditions which future regulations should address.