Safe Speed Forums

If you go faster and faster round a bend until you crash you would judge the speed / risk relationship to be low low low then instantly maximum. It's like a switch as soon as you exceed the speed where you can negotiate the bend all higher speeds fail.

Now let's try it with ten vaguely similar bends and average the results... Our average risk of not making it around all ten of the bends might end up as a plot with a steep transition, but it's no longer like a 'switch'

Now let's try it with hundreds of bends and hundreds of drivers. We've now got a smooth slope that looks like a speed/crash relationship, but actually it's an illusion - it's just an average of a load of on/off events.

This isn't a new observation - something very close is mentioned on http://www.safespeed.org.uk/speedlimits.html - but I'm starting to notice that it might be more significant than I had reaslised.

The real-world 'too fast' events ARE 'cliff failures' - once we're past the speed at which we can negotiate the hazard we DO crash. And the whole thing about incremental risk increases starts to look pretty silly.

Of course it would work with automated driverless cars - every tiny little more on the system speed setting would mean more crashes.

Anyway... Any thoughts?

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

Perhaps a better description would be threshold failures -speed below the threshold is safe and speed above is instant accident. The threshold speed would vary according to driver, car and conditions but there would be a speed where any car would crash.

Perhaps concentrating on reducing spot speeds in blackspots/dense hazard areas more and leaving the rest alone would be a more media friendly policy that could be promoted - it still keeps the speed kills that appeals to the numpties but subtly alters their familar message into speed kills in the wrong place/time so pay more attention. Reducing speeds under those circumstances would make a greater difference than trying to reduce the average speed gradually and smaller amounts I think. Safety policy is concerned too much with average speeds, average drivers rather than dealing with the dangerous margins of really rubbish drivers and really far too fast instances.

To be honest I would rather get rid of the 'speed kills' message completely, rather than simply modify or qualify it.

Sorry to be what some may feel is pedantic, but speed does not kill at all.

Best wishes all,
Dave.

I'm not sure I even understand the question fully to be honest!

Surely, the problem is that the threshold varies continuously? I can take bend "X" near my house in the dry, safely, at "Y" MPH. I could PROBABLY take it at "Y+10"MPH but have never fancied finding out because it's quite a long way down if I fall off the edge! Now in the wet, the speed is obviously lower. In ice, lower again. If a sheep happened to jump out of a field on to the road while I was part way round, that could change things too - and a diesel spill...

...and so on.


Am I missing the point here?

I like the idea above that cameras (or any other sort of enforcement technique) could be limited to VERY specific hazards. IF, for example, there was a junction just over a blind crest that really HAD claimed a sucession of lives, then I wouldn't mind a big sign saying "Blind Junction, camera-enforced limit of 50MPH, 100yds" (or something shorter).

Maybe if there was a notorious bend that kept claiming lives, the same thing could be done. What actually happens, though, is that if you get a few accidents within a particular distance of a spot where it is CONVENIENT to put a camera, that's where they put it. It's location might have NOTHING to do with the actual hazard 500 yards away. As such, any sensible driver who is aware of the hazards, will start to see cameras as irrelevant and unnecessary.

At the very least, if there was a (say) 2 mile stretch of road which really did NOT have any one point on it where all the accidents happened but over that distance had an unusually high concentration of accidents, they could (and I say this with plenty of reservations) AT THE VERY LEAST put up the customary camera warning sign at the start of the 2 miles AND THEN put a crossed-out camera sign (like the names of French villages when you're leaving them) at the END of the 2 miles. This, I believe, if RIGOROUSLY applied, would really start to make sense to drivers. If I'm (as often happens) driving along an unfamiliar stretch of road and I see a camera sign, I think "Ah, this must be the start of a dangerous bit of road with an unusually high acident rate. I'd best be careful". So, on I go, looking out for cameras (oops!, sorry, meant to say "hazards")! After a few miles, I start thinking, "well hang on a minute, the road is now completely different and I can't see anything even remotely hazardous, this is all a big con"!

If, on the other hand, I'd seen a definite start and finish to the "danger zone", I'd be a lot more accepting of the presence of a camera.

Of course, this would have the effect of only slowing people down for the hazardous bit whilst telling them that there was less chance of them being caught going faster in the following bit that wasn't hazardous. But hang on, isn't that what they WANT us to do? Obviously, such clearly signed hazard areas wouldn't actually make much money...

...oh dear, I think I've just spotted the fatal "safety" flaw in my argument!

And that's where the camera is sitting...

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Mike

Dave - from another Dave - speed don't kill - bad driving does ---

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lets bring sanity back to speed limits.
Drivers are like donkeys -they respond best to a carrot, not a stick .Road safety experts are like Asses - best kept covered up ,or sat on

I quite like Mole's idea of using the threat of a camera as an extra warning of a specific hazard or dangerous piece of road. Trouble is though, if, say, a limit of 40mph was strictly enforced at a particular location, and due to adverse conditions for some reason, on a particular day it was only safe to proceed at 30mph, people would still do 40mph. Same old problem.

The only way to reduce 'cliff failures' is to educate drivers. Maybe advisory maximum limits could be utilised as a guide to inexperienced drivers whilst their judgement improved, but we need to be in a situation where we can rely on drivers to make responsible and informed judgements about all hazards. Obviously this also requires adequate visibility / signage of the hazard to work.

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Science won over religion when they started installing lightning rods on churches.

further to this, why not use coloured tarmac? Red in areas that are exceptionally dangerous, or even red boundaries to any corner chevrons etc?