BY any measure of the right foot or the imagination, the effect speed cameras have had on motorists using Worcester's City Walls Road is dramatic, to say the least.

If the evidence of one sample study week can be taken as an average, in three months the number of speeders on the busy 'racetrack' has dropped from an alarming one-in-two to fewer than one-in-five.

Their introduction in April was greeted with predictably mixed feelings by the public.

At 35mph, it takes a further 21ft to stop than it does at 30mph and a pedestrian hit is twice as likely to be killed.

Those are sobering facts which ought to be enough to persuade anyone to strap a ballet shoe to their right foot, in place of the diver's boot. But we know that won't happen.

That's why we back West Mercia police's decision to prosecute anyone caught driving above the speed limit "by 10 per cent plus 2mph".

It means people like Jim Whitehurst, who was caught twice in June, are going to have to be philosophical and be thankful that their bad experience wasn't made worse by a serious injury or death.

He believes that being caught doing more than 40mph would be "a fair cop". He was doing 35 and 36mph.

But we beg to differ.

We'll never know, of course, whether the 60 per cent of City Walls Road speeders who were forced to slow down might have gone on to kill or maim someone.

But, for the sake of gaining a few seconds on a half-mile stretch, is it a risk worth taking? Of course it isn't.