The technology exists to ensure all road traffic is regulated to safe speeds

When motor cars first appeared on British roads they had to be preceded by a man waving a red flag to warn the public of the approaching danger. As the number of vehicles has grown, many ways of ensuring the orderly management of traffic and public safety have been tried. Despite improvements in vehicle and road design, traffic regulation, and driver behaviour and despite reductions in accident rates, road traffic accidents remain a major cause of premature death or serious injury.1 Can anything further be done to reduce this toll?

The epidemiology of road traffic accidents is well known. For prevention the most important measures are separation—of streams of traffic from …