Government targets for England look to reduce by 40% overall the number of serious injuries and deaths on the nation's roads by 2010, (compared with a starting point - baseline - of the 1994-8 average figures). The target for those aged 15 or under is higher, at 50% reduction.
But when researchers compared police statistics (which the Government uses for its figures), and hospital statistics between 1996 and 2004, they found large discrepancies.
Police figures showed that by 2004, numbers of those killed or seriously injured had dropped by almost a third (from 86 per 100,000 population, to 59 per 100,000). However, the police statistics showed a much smaller decline in the number of people killed than the number seriously injured.
Police statistics showed a 32% drop in serious but non-fatal injuries. However, the researchers found that hospital figures for non-fatal road injuries showed that rates had hardly changed between 1996 and 2004.
The authors suggest the discrepancies are probably down to an increase in under-reporting of injuries in the police statistics and that, if there has been a decline in injuries, it is probably only in those considered by the police to have been minor.
More investigation is needed, say the authors, since the findings cast doubt on whether there has been much progress on the Government's target to date - and on its likelihood of being met by 2010. In practical and policy terms, much more needs to be done to ensure that there are real and substantial reductions in serious injuries on England's roads.