Sir: Lance Green (letter, 8 April) confuses the cause of road accidents with the outcome. It is true that speed may not always be a factor in causing an accident. However, an accident which involves vehicles travelling at high speeds is more likely to result in serious injury or death, whatever the cause. The statistics are frightening: approximately one in ten pedestrians survive being hit by a car at 40mph, compared with half at 30mph and nine in ten at 20mph.
Dr MARK DOUGHERTY
School of Transportation and Society