The Wiltshire and Swindon Safety Camera Partnership claims that three months of speed camera usage on the M4 highway in the UK has slashed serious road accidents by 64 percent. "This dramatic reduction in crashes is as a direct result of our strategy to enforce the national speed limit on this section of the motorway, no other changes have been made to slow traffic down or to make the road any safer," explained David Frampton, the Project Manager for the camera partnership.

That sounds like a significant benefit, except road safety experts say the camera officials are lying. "There is absolutely no mechanism by which their claims could be true," said Paul Smith, founder of the Safe Speed road safety campaign.

The Association of British Drivers (ABD) fought with the camera partnership for release of crash data under the Freedom of Information Act. According to the documents, the crashes cited in the formal justification for the placement of cameras on the M4 include:

• an accident where a pedestrian fell from a bridge
• an accident where a gust of wind pushed one truck into another
• several tire blowout accidents
• a crash where a car drove the wrong way

According to Smith, the accident data show that only about four percent of accidents on the M4 were actually caused by exceeding a posted limit. The documents rated the most and least important contributory factors as a percentage of accidents on the M4, as follows:

1. Inattention: 28%
2. Failure to judge others' path or speed (i.e. poor lane-changing): 28%
3. Lack of judgment of own path: 17%
4. Fatigue: 14%
5. Careless, thoughtless or reckless behavior:14%
6. Excess speed for conditions: 14%
7. Exceeding posted speed limit: 4.2% (SafeSpeed estimate)

"I would very much like to hear the Camera Partnership explain exactly how it is supposed to be possible that their cameras reduced crashes by over sixty percent when only about four percent of crashes involved exceeding a speed limit," Smith said. "It does not make sense."

"This data -- now we've forced it into the public domain -- raises very serious questions about the use of speed cameras on the M4," said ABD road safety spokesman Mark McArthur-Christie. "It also raises questions about why the data has not been made public before."