# Playing with numbers

There is a television series called Numbers, in which a mega-brained young professor of mathematics assists the FBI in solving crimes by using statistics, algorithms and formulae that predict what criminals are going to do.

Its appeal lies partly in the attractive characters, but also in the idea that life should be like that: there should a scientific answer to every problem. In real life, people with normal-sized brains use numbers differently – primarily to justify their own agendas.

For reasons that may not be unconnected with money, the road safety industry has over the last few years been anxious to attribute a very high percentage of accidents to excessive speed. Figures like 30% – sometimes even 50% – have been, and still are, bandied about, although the Government has admitted that speed is a contributory factor in only 6% of all accidents, and 13% of fatal ones.

Since these are government figures, we tend to distrust them, and the Government is not likely to be downplaying the role of speed, so maybe the true figure is even lower. Despite this, the drive towards lower speed limits continues, fuelled by the disproportionately loud voices of those who don’t like cars anyway and want you to walk, cycle or bus everywhere. A big advantage to driving is speed; so they naturally want to make driving slower.

Certain road safety groups also have an obsession with speed, and a more-than-willingness to be free with their use of figures. Brake, for instance, confuses driving speed with impact speed when it claims that a car travelling at 35mph is twice as likely to kill a child as one travelling at 30mph. The statistic actually refers to impact speed, which is quite different: a car travelling at 35mph is unlikely to hit anyone at 35mph unless the victim suddenly materialises in the road. There would be braking and an attempt to avoid collision. The impact speed is likely to be much lower.

It could be counter-argued that a driver travelling at 35mph would be that little bit more alert, and without aggressively policed speed limits (yes, I mean cameras, fines and points), he might not be looking at the speedometer instead of scanning the road and pavements ahead for possible hazards.

But no such arguments are admitted, and we have recently been told we live in the speed camera capital of Europe. The Department of Transport justifies itself by saying that its policies have cut deaths or serious injuries by 17,000 a year while making about £100 million in fines.

Why include serious injuries in these figures? Well, “serious” is pretty hard to define, and the actual figures for serious injuries depend on who has been collecting them. Also, it muddies the water, which can be useful.

The independent pressure group Transport Watch on the other hand blames speed cameras for increasing fatal accidents, to the tune of almost 10,000 deaths since their introduction in the 1990s. It argues: “Between 1980 and 1995 UK road deaths were falling 7.1% a year. But since speed cameras arrived, deaths have fallen just 2.8% annually.” The other thing that has fallen, of course, is police patrols. There are 4309 speed cameras in the UK, and just 1904 police traffic patrol cars.

Clearly at least some of these numbers contradict each other. The problem with numbers is that they deceive us into thinking they are magical: they can solve everything, or reveal everything. Arguments based on common sense take a back seat because the numbers are somehow mysteriously heavier: they carry more weight.

The real threat to road safety is not speed: it is bad driving. Police patrols are better able to deal with this – when they are there. But mostly they are not.

The average motorist does not drive recklessly, but nevertheless has his collar felt and is made to feel like a criminal. Meanwhile those who drive with their eyes glued to the speedometer survive, but are a much bigger risk to other road users. The very few dangerous speeders seem to carry on regardless.

And many drive dangerously slowly in the current climate, either through incompetence or fear, or not realising that road safety is improved by those who don’t dither when joining or leaving faster traffic; who don’t hold up queues of cars that clearly would like to progress a little more quickly; and who don’t move snail-like into the outside lane about three miles before they intend to turn right.

Yes, but what are the numbers? The fact is, they are just about anything you want them to be – as you can see by clicking here and here. Happy motoring.