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You're nicking the WRONG people!
North Wales Police have caught themselves out, without even noticing.


SafeSpeed Commentary

In a spectacular display of ineptitude North Wales Police have admitted that their speed cameras are targeting the wrong drivers, and they didn't even know they were admitting it.

Refer to the following table: 
 

Age range tickets (number) tickets (%) Accident involvement % (2001) effective error
Under 25 1,317 3.6% 25.5% 14% of expected
35 to 54 17,256 47.3% 24% 197% of expected
other 17,901 49.1% 50.5% unknown
Total 36,474 100% 100% -

Accident involvement data from (RAGB) table 6c. Some adjustments are required to match the age range claimed by North Wales Police, but the max expected error is under 1%.

A lot of traffic is due to the 35 to 54 age range. It's about 10 times the traffic from the under 25 age group. Yet the middle age drivers only contribute about the same number to the accident statistics. (Note also that 35 to 54 is a 20 year age range, while "under 25" is only a 8 year age range.)

It's probable that the ratio of tickets reflects the ratio of the traffic, but it clearly does not reflect the ratio of accident risk.

You do not need to consider the ratio of young drivers to middle aged drivers in the traffic to know that the systems is missing its mark. For example: Even if the dangerous group of young drivers only made up 1% of the traffic they are still responsible for 25.5% of the danger, and if the cameras targeted them correctly they would still get 25.5% of the tickets.

Never forget that the young and inexperienced have their high accident rates for the following reasons:

  • Inexperience, implies undeveloped hazard perception which implies failing to slow down when necessary and unsafe speeds.
  • The over confidence of youth, potentially leading to unsafe speeds and risk taking
So we really must expect the young to be worse speeders. After all it's poor speed control which will be a significant component of their accident involvement. And we're not talking about speed limits, we're talking about the unsafe use of speed. But even this hasn't enabled the North Wales cameras to identify them.

Everyone knows from insurance adverts that middle aged drivers are the safest group and pay the lowest insurance premiums. And everyone knows that young drivers are a dangerous group. There's a brief report (here) Yet it's the middle aged drivers who have received the greatest proportion of the tickets. 

This is clear proof that speed cameras target safe and dangerous drivers and behaviours entirely without beneficial discrimination. Exactly as we've always claimed. There's even a suggestion of negative discrimination, meaning that safer drivers have been prosecuted in greater proportion. 

new Northern Ireland

Compare the above with this story from the BBC (click here). It contains the following:

"A total of 80% of fatal car crashes involving speeding in Northern Ireland are caused by men between the ages of 17 and 24, it has been revealed."

So that's 3.6% of under 25s get speeding tickets in North Wales and 80% of under 25s cause "speed related" accidents in Northern Ireland. That's a ratio of 22:1 Does anyone smell a rat?

How on earth can anyone suggest that speed cameras are going to make a difference? They don't catch the right people.

Other claims - they are joking.

"Crashes down by 80%!" and "KSI down!" Are typical of the daft, erroneous and misleading claims made by the spin doctors at the speed camera partnerships. The other claims in this news clipping are no exception. We recommend understanding the methods that they use to create the misleading figures, and especially the "regression to the mean" error. We have documented the sorry process (here).

The National accident trends are really rather bad; the worst we've seen in the UK since the 1960s. We have a full collection of graphs (here) and an analysis of the fatal accident trends (here). Don't believe a single claim that the speed camera partnerships make until you see the benefits in the national accident trends. (which, of course, you won't).

An email sent to the author of the newspaper article:

Subject: Road casualty figures - the reality.
Date: Fri, 28 Feb 2003 01:54:33 +0000
From: Idris Francis <email@withheld>
To: hugoduncan@email_withheld

Dear Mr. Duncan,

Your article in the Daily Post identifies older drivers as speeding more often. It would be interesting to compare the figures given for different age groups caught speeding with those for the same groups involved in accidents - if possible with adjustments for average mileages covered. The lower insurance rates for older drivers suggest that they would do well in 
such a comparison!

I regret to advise you that some of the road casualty figures in your article are misleading. I assume that you were given them by the Arrive Alive people, who, in common with many police forces, are prone to selective presentation to give the impression that their policies are succeeding, even when they are not.

I obtained from North Wales police only days ago the most up to date figures available - Jan to Oct 2002. The full year figures will not be available for some weeks. I attach a graph giving the official figures for fatal, serious and slight injuries and show below the discrepancies:'

Your article states 'on all N Wales roads road fatalities were down 24%' but fatalities were 18% down compared to the 1998-2000 baseline. and only 10% down compared to 2001

You state that 'there was also a 34% reduction in serious injuries' on roads targeted by Arrive Alive - but on all roads, serious injuries were down 17% compared to the 1998-2000 baseline and UP 1% compared to 2001.

You stated that there was a 20% reduction overall on targeted roads -

But on all roads, slight injuries (which typically represent 82% of all casualties) were down only 11% compared to the baseline, and only 2% down compared to 2001

I am sure you will agree that the figures printed give an over-optimistic view of what is happening - even more so when we recognise that fatalities fell by a factor of 2 from the mid 1960s to the mid 1990s, and that the real issue is not whether casualties are falling, after the new policies were adopted, but whether they are falling more rapidly or less rapidly 
than they did previously.

On the basis of the real figures, I see no reason to believe that the Arrive Alive policies - including the increasingly venomous campaign against drivers who, as it happens, have one of the best, if not the best, accident records in the world - are having any beneficial effect.

You will find much more information, if you wish to see it, on the web site http://www.righttosilence.org.uk

Sincerely

Idris Francis

Comments

Comments on the above are welcome. If there is a demand we will create a comments page. We will be delighted to publish all suitable emails including those whose content we disagree with. Email comment.

You can't measure safe driving in miles per hour

We have a strict editorial policy regarding factual content. If any fact anywhere on this web site can be shown to be incorrect we promise to remove it or correct it as soon as possible.
Copyright SafeSpeed 2003
Updated 23rd June 2003
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