Sunday, 8 March 2009

How fast is average? How fast is safe?

Looking through the online papers this evening, my heart has been sinking over the news that the speed limit on 150,000 miles of our road network is to be reduced to 50mph, monitored by 'average speed' cameras. Much of this will include roads in rural areas, and since one of the pleasures of living and driving in such an area is not having to cope with 'speed humps' and 'safety cameras' (both somewhat oxymoronic), my irritated reaction was almost instinctive.

Yet in fact, I have frequently remarked on, and warned new arrivals of, the fact that driving round here is vastly more dangerous than driving in, say, London. Since arriving in 1999, I have taken the funerals of two parishioners killed in road accidents, we lost a further two church members (father and son) in a single crash, and there have been three fatal accidents (including the one that killed one of those I buried) within the boundaries of the benefice. On top of that, I could probably identify another half-dozen fatal accident sites within a five mile radius.

Compare this with the fact that when I lived in the East End of London for seventeen years I knew of just one fatal road accident in the immediate locality, and you can see that actually there really is a problem.

And speed is a key factor. The difference between driving in London and driving in rural Essex is that in London it is hard to get up enough speed to kill yourself, or even a pedestrian or cyclist, in a car accident. Since the average speed of traffic in London is something like 9mph, it is obvious that whilst the number of bumps and shunts may be high, the number of potentially fatal collisions is limited.

This, however, is due in large measure not to the proliferation of 'traffic calming measures' but to SWOT: sheer weight of traffic. The one thing, for example, that amuses me when I try to cross the Thames via the Blackwall Tunnel is that I regularly drive past one speed camera at a crawl, thanks to the queue of traffic which seems to be there day and night. I doubt whether it has flashed someone in a decade.

No, my irritation at the news about rural speed limits is not that speed doesn't matter, but that the proposed measures are not the answer, for two reasons.

First, speed, per se, is not the cause of accidents. The one accident I had in my last car occurred at about a mile an hour, when I backed over a steel post situated below eye-level. Nasty. On the other hand, the one time I came close to a serious accident in the same car was when I was going too fast into a bend. But I was driving well below the (60mph) speed limit.

Both these situations resulted not from 'breaking the speed limit' but bad luck in the first instance and bad driving in the second.

Speed is undoubtedly a critical factor in the seriousness of accidents. Kinetic energy increase geometrically with an increase in velocity. If you hit something at 60mph, it involves 4 times the energy of the same impact at 30mph. All that energy has to go somewhere, and you'd better be right with God if it has to go through you. So it is actually very important indeed not to drive too fast. But that is a matter primarily of good driving, defined by the old police driving manuals as essentially being always 'in the right place, at the right speed, in the right gear'.

But the second problem with the proposed scheme is the idea of monitoring these rural roads with average speed cameras. That works on a straight stretch of uninterrupted carriageway where there is nothing else to stop the driver bombing along at 80+. But how would it work on a rural road with bends?

The problem is simple: an average speed is just that - a sum of highs and lows, faster and slower. So what do you set on the speed camera? If you drive up the B1383 from Newport to Little Chesterford, you should at no point exceed 50mph. If you drive the same route at a constant speed of 50mph you are probably on a motorbike. If you manage it in a car at an average speed of 50mph, allowing for bends, you will have broken the law. If you manage it at a constant speed of 50mph in a car, you are probably a menace to yourself and to others.

One of my known fatal accident sites is on just that road, where a novice driver left the road approaching a bend and hit a brick wall. Almost certainly he was going too fast. But what mattered was how fast he was going then, not how fast he had been travelling on average.

On most rural roads your average speed must be lower than the speed limit if you drive within that limit. But how much lower will depend on the vehicle, the road conditions, the weather, the time of day, and so on. There is no one safe average speed.

By the same token, there will be a speed above which almost no-one could ever drive safely along the entirety of a particular route. But it would be nonsense to set that as the average 'limit'. Yet if you set the limit, let's say, just below that, this doesn't meant the result will be an outbreak of safe driving. It is perfectly possible, as I discovered, to be driving well within the speed limit and yet still be driving too fast for safety.

I am all in favour of observing the speed limit. But more than that, I'm in favour of safe driving, which means developing and practicing driving skills. So why don't we find a way of encouraging that?

Why not, for example, limit the number of passengers that can be carried by young drivers, since it is a proven fact that the more passengers there are, the more likely it is that there will be an accident?

Or what about a government-sponsored 10% per annum 'no claims' bonus, rising to 90% of the premium after nine years? It would be a good deal cheaper than 'safety cameras', and I reckon would do a great deal to encourage careful driving.

Or why not a 50% reduction in road tax for any car registered to a driver who has passed the Institute of Advanced Motorists' test, and who hasn't had an accident or any points on their license in the last three years?

What is needed is not more regulation but a 'safety' culture based on roadcraft. My own firm conviction is that the recent decline in safety on Britains roads is not because we are going faster (we are not). It is because we are driving worse.

John Richardson
8 March 2009

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  1. Michael Roberts9 March 2009 at 10:31

    Round here, rural Lamcashire, the highest fatalities are among the young, often in souped up little Citroens . And of course idiots on motorbikes who frequently exceed 100 in my large parish.

    I see driving both from a car and a bicycle (3000miles a year on country roads) . It is amazing where some people overtake.

    A problem with the younger generation is that they often dont cycle which is a good way of learning road conditions and the dangers of roads. - gravel does funny things to tyre grip! So from being a passenger they are suddenly in charge of a 100mph machine (few cars arent)

    As for IAM , no thanks. One of the worst drivers I know is proud of being IAM and I once was stuck behind a car in the outside lane of dual carriageway doing 65 with no cars in the inside lane and would not let me past at 70 - all legal. It was a driver under IAM instruction.

    So what do you do?

    What about only allowing those who cycle 1000 miles a year to drive cars?:):)

  2. Could it be for all the "right" comments the government just wants to raise cash. E.g. making it more expensive to drive so we use public transport, whilst public transport still goes up in cost.

    Darren Moore