A furious dispute broke out yesterday over an independent report that claimed speed cameras were saving more than 100 lives a year.

A furious dispute broke out yesterday over an independent report which claimed that speed cameras saved more than 100 lives a year.

The Association of British Drivers (ABD) said the figures were "meaningless" as there had been no substantial reduction in accidents, while a government transport adviser warned that sceptics would end up with "blood on their hands" if they ignored the findings.

An analysis by University College London, published by the Government, showed the number of people killed or seriously injured at camera sites fell by an average of 40 per cent over three years to mid-2003 with a benefit to society of £221m a year. The reduction in the number of collisions involving injury varied from 11 per cent in Leicestershire to 72 per cent in West Yorkshire.

Mark McArthur-Christie, safety spokesman for the ABD, argued there had been no substantial overall decrease in accidents since cameras began to be installed. He said that while there may be a "cluster" of accidents at one site in one year, there would often be a cluster at another site the next year.

David Begg, chairman of the Commission for Integrated Transport, a government advisory body, said: "Today's report proves that speed kills, that cameras reduce speeds at accident spots and they prevent injuries and save lives." Critics of speed cameras would "end up with blood on their hands".

The Department for Transport said casualties had risen at 743 out of the 5,000 sites, but a spokesman said many cameras had not been in place long enough to judge their success.