Amusingly, in today's Observer, Mary Williams of Brake is quoted as saying:"... Brake maintains [speed cameras] can reduce casualties by around 42 per cent on routes where they are sited."

The Safe Speed road safety campaign would very much like to hear Mary Williams explain how it is possible for speed cameras to reduce crashes by 'around 42%'when recent figures only associate 5% of crashes with speeding. Surely, even with 100% compliance at speed cameras sites, there could never be more than a 5% reduction in crashes? And with 100% compliance, no fines would be issued.

We now know (as a society) that many modern road safety claims are bunk simply because they DO NOT FIT with other claims and known data.

* They say crashes down by 42% at speed camera sites, yet only 5% of crashes involve a speeding vehicle.

* They say 'It's 30 for a reason' because 20% of child pedestrians die in 30mph impacts, but only 0.43% are dying in built up areas with 30 and 40mph speed limits.

Paul Smith, founder of the Safe Speed road safety campaign(www.safespeed.org.uk) said: "I challenge Mary Williams (or any representative of her choosing) to debate the issues of speed and safety in any print or broadcast medium."

"The problem really is that very few people have looked deeply enough into the road safety data to tell us what it really means. Society is latched onto gross oversimplifications, false assumptions and dodgy data."

"Around four hours before the release of Government data on the proportion of crashes caused by speeding, Safe Speed issued a PR warning editors and journalists what to expect. We were exactly correct. We'd had no leak of the data. It is just that the Safe Speed campaign has taken the trouble to understand the road safety information in enough detail to understand what's REALLY going on."