By 2013 the speed limit on motorways in England and Wales could increase from 70 mph (113 kph) to 80 mph if the coalition government has its way. Its stated aim is to achieve “hundreds of millions of pounds of benefits for the economy,” and it dismisses concerns about health consequences, claiming that advances in car safety have resulted in deaths on British roads falling by more than 75% in the past 55 years and that almost half of all drivers break the current limit anyway.1 Are they right to dismiss these concerns so lightly?

The current 70 mph speed limit was trialled in 1965 as a direct response to a series of fatal multiple collisions in fog. Before then speed was unrestricted outside built-up areas. By 1967 the Road Research Laboratory concluded that this restriction had led to a reduction in road fatalities,2 and Barbara Castle—then minister of transport—made it permanent. Since then the number of serious and fatal …