Safe Speed Forums

DfT websites will still contain the 42 per cent claim, but there will be further explanation

DfT 'unwittingly' bigged-up speed camera benefits
By Jane Fae Ozimek Posted in Government, 29th July 2010 11:01 GMT

Rumours of their awesomeness exaggerated, dept admits to Reg.
Exclusive The Department for Transport (DfT) has "unwittingly" misled the public over the benefits of speed cameras for the last four years.
That was the shock admission yesterday by a DfT spokeswoman, when finally cornered by the Department’s own research. She also told us that they have finally agreed to put matters right by adding an explanation to future public statements.

The misinformation began with a report produced by the DfT (pdf) itself in 2005. On the basis of this report, it came up with the now infamous claim that speed cameras are directly responsible for reducing the level of killed and seriously injured (KSI) at camera sites by 42 per cent. Yet its own evidence barely supported half that figure.

The claim has been repeated frequently by official spokespersons and road safety campaigners, and on the DfT’s own Think! road safety website. It has also been regularly questioned by speed camera opponents, who point out that other effects should be taken into account. These include overall "trend" improvements in the KSI rate, other road safety measures put in place at accident black spots, and a statistical quirk known as "regression to the mean".

That last factor is important. Scientists and statisticians have long been aware that whenever something out of the ordinary happens – from a plague of frogs to a spate of road accidents - it is probably just that: a freak, a fluke, an anomaly. Anything that you do in that location after the event will look as though it makes a difference – but it hasn’t. The figures would have returned to a more normal average rate of their own accord anyway.

When the DfT first started claiming such a high benefit for speed cameras, respected academics Dr Linda Mountain of Liverpool University and Mike Maher, Professor of the Mathematical Analysis of Transport Systems at Leeds, objected. The DfT took notice, and the 2005 report included an appendix supplied by this pair showing in meticulous detail how the effect of speed cameras was almost certainly less than half the 42 per cent quoted.

The Reg has raised this with the Department for Transport many times since. On each occasion we have been fobbed off. In one instance, a spokesman told us that statistical analysis was no more than "a matter of opinion".
So far, so stonewalled - until this week, when the DfT decided that speed cams were no longer quite so deserving of central government support. Once more we drew their attention to this issue, expecting to be brushed off again. At long last, a spokeswoman told us: "This was basically an oversight and it will be corrected."

We checked: she confirmed. In future, DfT websites will still contain the 42 per cent claim, but there will be further explanation – or so we have now been assured.
A quick check of the Think! site shows the figure has already been changed. ®

DfT denies deliberately misleading on speed cam stats
By Jane Fae Ozimek - Posted in Government, 2nd August 2010 12:43 GMT

As Swiss prepare for new supercams.

The Department for Transport last week denied deliberately misleading the public by exaggerating claims of the beneficial effects of speed cams.
This follows an exclusive report in The Register, revealing that the DfT now accepts that its claim that speed cams on average lead to a reduction of 42 per cent in the Killed and Serious Injury (KSI) category on the roads may have "unwittingly" misled the public.
Although the headline reduction in KSI at speed cam locations reported in a 2005 study was 42 per cent, a review by academic experts in the field of transport statistics showed that more than half of this effect was not due to speed cams, but to other completely unrelated factors.

Despite this and the fact that the DfT’s own report included the academic critique, the figure almost always quoted in official publications was 42 per cent. When we first raised this issue two years ago, the official line was that this was the "correct" figure – and the department would not budge from that assertion.

Last week, all that changed, as a spokeswoman told us: "This was basically an oversight and it will be corrected."
So why had the figure not been corrected before? She added: "The alternative views were always available in the report, which was made publicly available at the time."

She also categorically denied any link between the government’s apparent U-turn on speed cam policy and the DfT’s desire to reduce the headline figure.
Meanwhile, events are moving fast as at a meeting last Tuesday Oxford County councillors slashed funding to the Thames Valley Safer Roads Partnership (TVSRP) by £600,000 following a reduction in cash from central government.

TVSRP responded by stating that this effectively meant the end of the speed camera experiment in Oxford, and according to official sources the body has spent the last week gradually winding down the service. As of yesterday (1 August), the county’s 72 fixed speed cameras, seven red-light cameras and 89 mobile cameras are no longer snapping at passing motorists.

This follows similar action in Swindon last year – but while Swindon merely switched off a handful of fixed cameras, the Oxford action is much further up the scale. A spokesman for TVSRP told The Register that it had concerns about the safety effects of this decision, citing long-term research by TVSRP that appeared to suggest a 36 per cent reduction in KSI within the county as a result of speed cams, even taking into account regression to the mean effects.

As some British motorists celebrate their new-found liberation from automated policing, inhabitants of the Swiss city of Geneva may soon be complaining about a new generation of speed camera that is supposedly capable of detecting up to 10 kinds of traffic offences.

According to Le Matin, quoting a story in local newspaper Le Matin Dimanche, the cameras will initially focus on conventional matters such as speeding and red light offences. They will go into service at the end of August.

However, they are also capable of picking up motorists who tailgate, fail to give way to pedestrians or to traffic on the right, and those who overtake in a dangerous manner. These capabilities will gradually be enabled in a pilot run by the Swiss Police.

Unlike current cameras, which can monitor only two lanes, the new super camera can allegedly watch four lanes at a time, following up to 22 vehicles simultaneously over a distance of 500 metres.

Following initial testing results, Jean-Marc Pecorini, head of Geneva canton's traffic police, told the newspaper: "We are very satisfied with the equipment."

The new Trafistar SR590 radar system is built by Zurich-based, Multanova. ®