More evidence is needed to prove the effectiveness of speed cameras in reducing road deaths, injuries and collisions, according to researchers in Britain.
Academics in the University of the West of England and the University of Bristol reviewed 14 studies of cameras in different countries including Britain, Australia, Canada and New Zealand.
The report, published in the British Medical Journal, said the studies showed road deaths were reduced in all cases, but by widely varying amounts.
Deaths were reported to have been cut by between 17 and 71 per cent at speed cameras sites, while collisions were reduced by between 5 and 69 per cent and injuries by between 12 and 65 per cent, according to the 14 studies.
"Published research consistently shows the effectiveness of speed cameras in preventing road traffic collisions and injuries," the study says. "However, the evidence is relatively poor, and better data need to be collected to improve the evidence base."
The report said measures to make roads safer are multifaceted and the introduction of speed cameras in the 14 studies may have been accompanied by other road safety initiatives which could have effected the results.
Only a handful of speed cameras are in operation in Ireland at present. Many of these were found last year to be defective, resulting in a reduced conviction rate.
The Government plans to outsource speed cameras to private companies, which would see a large increase in the number of them in operation.
However, this move is at least a year away. Britain, which has hundreds of speed cameras across the country, has the lowest rate of fatal crashes in the European Union. Ireland ranks seventh out of 15 states, while Portugal has the highest.
The report advises countries planning the widespread introduction of speed cameras to do so in a controlled fashion "spread over a few years with careful collection of data on collisions and injuries, hence producing a natural comparison group."
The authors of the report said while research showed speed cameras were effective but more research was needed.
Co-author, Snajay Kinra, of the University of Bristol said: "The quality of research evidence is not very high."
"We have suggested ways in which the evidence could be made clearer by careful data collection.
"It is imperative that the authorities introducing new speed cameras carefully consider our suggestions. Otherwise, these opportunities will be lost and we may never be completely certain".
Meanwhile, a Co Armagh-based company which sells speed detection devices to motorists has reported a "massive increase" in sales since the introduction of kilometres per hour last month.
Wayne Lyons, who owns speedcameradefence.com, said more than half of his business was generated from the Republic. "When kilometres changed it was like when penalty points happened. It went bang, the phone was like a hotline," he said.