Nine buses and coaches were tested to experimentally determine various parameters considered to affect rollover stability:​ principally, spring stiffness, position of centre of gravity, and roll moment of inertia. Utilising these data, a computer simulation of a typical rollover accident was used to compare the relative performance of the different vehicles and investigate the effect of each parameter on the rollover threshold. Height of the centre of gravity and, to a lesser extent, roll centre height were found to have the greatest effect.