That's not true - (based on DoT stats) only a small proportion of accidents are caused by inappropriate speed.
Urban myth. One report, which is not designed to focus on accident causation, suggested speed is not a large factor in RTCs. This has been endlessly and dishinestly cited by the pro-speeding lobby. This use of statistics has been described by a professional statistician as ‘extremely naughty’ and by the Department of the Environment, Transport and the Regions as ‘mischievous’.
Virtually the only factor that road accidents have in common is that all would have been avoided if those involved had known with certainty, a few seconds in advance, that an accident was about the occur.
Lower speeds provide those few extra seconds.
The ‘robust general rule’ relating crash reductions to speed reductions: for every 1 mph reduction average speed, crashes are reduced by between 2-7%.