Abstract
Analysis of accidents at 42 roundabouts at which yellow bar experimental carriageway markings had been laid on an approach road, showed an over-all reduction in the proportion of speed-related accidents on these approach roads of 57 per cent. The markings appeared to be most effective in reducing fatal and serious injury accidents, whilst still reducing slight injury accidents. They were more effective in daylight than after dark and appeared to be most effective when the road surface was wet, rather than dry. They were highly cost-beneficial and the accident reduction was maintained at seven pilot sites for which data for four years after installation were available. (Author/publisher)