The Herald has a story from the UK Independent:
Earlier this month Oxfordshire council switched off every speed camera in the county and, judging by their speeds and the fanfare which accompanied the news, the drivers know it.
What they did not know, however, is that the film was left inside two of the speed cameras for a five-day test period. During that time the cameras secretly recorded the speed of passing cars.
And, while the drivers will face no prosecution, the results of the experiment proved what road safety groups feared: with the Gatso cameras out of action, drivers simply ignored the speed limit.
On Woodstock Road, 110 drivers were caught travelling at more than 35mph along the 30mph road in the five-day test period. That’s 18 per cent more than the number of drivers who used to be caught speeding in an average week.
It is a law-breaking trend which, owing to Government budget cuts, could soon be replicated across the country. And it is a situation which has provoked anger from road safety groups and senior police officers who say lives are being put at risk.
Sounds awful doesn’t it. Life without speed cameras. But let us look at what the numbers mean. The 110 drivers speeding was 18% more than normal. SO normal is 93 drivers speeding. That means over five days 17 more drivers sped, or basically three drivers a day – one every three hours.
Now we don’t know how many cars drive down Woodstock Road, so we can’t work out what the prevalence of speeding was, but let us assume a car every 30 seconds, which is around 1,000 cars during the working day.
With speed cameras there were 19 cars speeding, which is a 1.9% prevalance rate. Now it is a 2.2% rate. So the speed cameras slow down say three cars in 1,000.
So hardly the disaster the Independent reports – whose reporter obviously didn’t think to apply a critical eye to the claims of lobby groups.
Note I am not necessarily saying it was a good idea to turn speed cameras off. I am just pointing out that the effect has been minor.