Speed cameras are saving 100 lives every year, according to a government study published on Tuesday.
The spread of electronic speed enforcement has been controversial
The three-year study of accident rates on roads with cameras shows a 40% cut in the number of people killed and seriously injured.
The number of cameras in England and Wales is growing. There are now around 5,000 fixed speed cameras and sites where mobile cameras are often located.
Ministers hope the latest figures will help counter the cameras' unpopularity.
The Department for Transport has published statistics on almost 2,300 speed cameras across the UK on its website.
Motoring organisation the RAC broadly welcomed the report, but believed it may "compound confusion".
FATALITIES AT CAMERA SITES
Per year before: 265
Per year after: 160
Absolute change: -105
Percentage change: -40%
Figures are annualised averages and relate to 3,376 camera sites in partnership areas
Source Dept for Transport
A spokeswoman said the RAC was always supportive of measures such as speed cameras where they are proven to reduce deaths and serious injury.
But she added that the RAC felt the report would "compound confusion" for drivers "who were told... that the government had audited every single camera and could confirm that they were in proven accident black spots."
She claimed the government had committed an "about-turn" by publishing the new report, which admits that some cameras are in the wrong place.
But Transport Secretary Alistair Darling told BBC News that the 40% reduction in serious injuries and deaths at camera sites proved that cameras are working.
"When people see the figures they will be able to see for each camera site why they were put there because we will show the number of deaths and serious injuries in the three years before they were set up, and the after figures as well.
"People can judge for themselves. If a camera site isn't working, or people say 'look I can't see why that camera site is there', then the police need to look at it."
Mr Darling added that 10 people every day are killed on the UK's roads for a number of reasons.
"Of course we have got to look at other offences on the roads, dangerous driving, people who are driving without insurance or MOT.
"But in the overwhelming majority of cases cameras have worked."
The AA Motoring Trust also welcomed the government figures, but said that a funding system is needed to convince the public.
"What we really need is a better way of funding cameras and road safety as a whole," said Andrew Howard, head of road safety for the AA.
But he added: "A system that removes the raising revenue concern and funds all affordable, effective safety measures - not just the camera schemes."
Mr Darling said that total fine receipts were £68m, of which £54m was spent on running costs of cameras.
"The best camera is the one that doesn't raise a single penny because it is encouraging people to slow down," Mr Darling added.