SPEED cameras in Bucks have made no difference to the number of serious or fatal crashes in the past five years, according to an inquisitive motorist.

Electronic engineer Dave Finney has collated data from the Thames Valley Safer Roads Partnership (TVSRP) website, and says there has been exactly the same number of crashes in the five years after cameras went in as there were before.

He said: "In other words there's been no improvement whatsoever."

Mr Finney's revelation relates to crashes where someone was killed or seriously injured (KSI) at the then 39 camera sites across the county.

He has also collected data for three and four years before and after cameras were installed, which even turned up some negative figures.

Mr Finney's figures have shown there were 44 KSI collisions four years before cameras were installed in 41 locations and 50 four years after - an increase of eight per cent.

Slough-based Mr Finney, who has been driving for more than 40 years, said he decided to investigate performance figures of cameras across the Thames Valley "on a whim".

"All I did was extraordinarily simple. I found the list (of figures), went to each in turn, copied and pasted numbers into an Excel spreadsheet and added them up - that's it," he said.

But TVSRP has hit back at his figures and says the number of collisions at speed camera sites has dropped by 24 per cent in the last three years.

Richard Owen, TVSRP operations manager, criticised the way Mr Finney worked out his numbers.

He said: "It's very difficult to look at our website and work out precisely what was happening before and precisely what was happening after. I've told him I will be giving him our main data so he can look at it in more detail."

He added TVSRP only uses the three years before and after a period to analyse its data because there was a change in the wording of accident forms after 1998, and because not all sites have figures available for five years before and after.

He added: "Fourteen per cent on average of all collisions between 2000 and 2007 had one of their causation factors as speed-related.

"When you look at fatalities it's 27 per cent in the most serious, tragic collisions. It's a much more prevalent factor, which is not a surprise really."