An examination of UK hospital statistics by Oxford University and the South East Regional Public Health Group concludes that the number of road crash injuries has not declined since 1996, despite government claims to the contrary. Using figures provided by police, the Department for Transport has consistently claimed a decline in the worst types of accidents as evidence to support the continued use of speed camera enforcement.

"The discrepancies are likely to be down to under-reporting of accidents to police," the lead researcher, Dr. Mike Gill, told BBC News.

Paul Smith, founder of the Safe Speed road safety campaign explains that a sudden and isolated drop in the number of serious injuries reported by police in 1998 was caused by a change in the definition of "injury" used by police.

"We fear that there might be cases where pressure from government and partners may encourage the regrading of casualties from serious to slight in order to maintain performance indicators and to meet targets," Smith said. "The roads are not getting safer. Government road safety policy -- supported only by dodgy statistics has failed -- and we can see it has failed."