Speeding Does Not Cause Accidents
Discussion
Phatboy317 said:
Jon1967x said:
The risk from lightening is proportional to the time exposed and not the distance travelled.
You seem to be suggesting that if you slowly walk a mile through a storm that you have less chance of being struck by lightning than if you run half a mile, because you're covering less distance?Phatboy317 said:
emmaT2014 said:
So probability does and does not have a significant effect! Which is it?
No practical effect. A driver, on average, drives their whole lifetime without running down a pedestrian. Slowing them down to 20mph isn't going to make the slightest difference to that figure.
Just like you'll probably never be struck by lightning, or win the lottery.
emmaT2014 said:
The PRT has quite a wide variance and seldom stays the same even for individuals. It is the variance in PRT that is a significant factor in rear-end shunts in motorway and dual-carriageway collisions. In practice the PRT of 0.67s that is chosen as the illustration of thinking time and a part of the overall stopping distance in the Highway Code is better than that seen in practical tests. The additional two seconds is never superfluous because you just don’t know when you will need it.
I was tempted to simply say you are an idiot. Perhaps an explanation of why you are is better.
The discussion wasn't about PRT, and as the insistence was that all things should be kept equal, that's what I did.I was tempted to simply say you are an idiot. Perhaps an explanation of why you are is better.
BTW, I'll ignore the adhom - I won't sink to your level.
Slowing down does make a difference when all else is kept equal; the speed is part of the probability equasion in probability of a traffic collision.
I think you will find you are in a circular argument in your own reasoning.
Dammit said:
And the risk of being struck by lightning hasn't got anything to do with the odds of a pedestrian walking into the road without looking, or a ped walking out onto a zebra crossing whilst the driver stares out of the side window, wondering whether that's a deer or a pony.
This being the case, how do we ever justify travelling at more than 20mph, or indeed travelling by motor car at all?heebeegeetee said:
Dammit said:
And the risk of being struck by lightning hasn't got anything to do with the odds of a pedestrian walking into the road without looking, or a ped walking out onto a zebra crossing whilst the driver stares out of the side window, wondering whether that's a deer or a pony.
This being the case, how do we ever justify travelling at more than 20mph, or indeed travelling by motor car at all?It's the same reason our emergency services aren't subject to speed limits in some circumstances.
We grade the risk, pretty much - and try to control it.
Motorways are the safest roads as we've designed them that way, despite the high speed - lowest incidence of junctions per mile travelled, single direction of travel, no requirement under normal use to vary speed outside of a set window and no (usual) requirement to stop.
But yes - your point is a good one, we have, as a society, set a quota for human deaths per year that we are willing to accept in return for being able to drive to the shops.
EDIT to add: from here we have 1,730 deaths in 2013, https://www.gov.uk/government/statistics/reported-...
Which at the estimated cost of £1.6M per death puts the (financial) cost to society at £2,768,000,000 per year.
Actually, doing some Googling to support that figure it appears it's higher now- 1.74M
Motorways are the safest roads as we've designed them that way, despite the high speed - lowest incidence of junctions per mile travelled, single direction of travel, no requirement under normal use to vary speed outside of a set window and no (usual) requirement to stop.
But yes - your point is a good one, we have, as a society, set a quota for human deaths per year that we are willing to accept in return for being able to drive to the shops.
EDIT to add: from here we have 1,730 deaths in 2013, https://www.gov.uk/government/statistics/reported-...
Which at the estimated cost of £1.6M per death puts the (financial) cost to society at £2,768,000,000 per year.
Actually, doing some Googling to support that figure it appears it's higher now- 1.74M
Edited by Dammit on Sunday 26th October 10:39
I believe Phatboy's theory rests on the idea that events such as a pedestrian running into the road are things that would happen anyway, whether he was driving past at the time or not. He's wrong for the following reason- quite often people attempt to cross roads in front of an oncoming vehicle because they have misjudged the speed of the vehicle and mistakenly believe that they have enough time to complete the action and get out of the way before the vehicle arrives.
If, however, the approaching vehicle is travelling at a speed in excess of the road crosser's expectation, that can of course lead to an accident.
There was a vivid example discussed here recently of this, a motorcycle approaches a junction at (NSL road) and a driver reckons he has time to turn into a side road, across the bike's path, before the bike arrives. He even cuts the corner to achieve this. But the bike was travelling at about 100 mph, and the rider is killed when he crashes into the car.
If, however, the approaching vehicle is travelling at a speed in excess of the road crosser's expectation, that can of course lead to an accident.
There was a vivid example discussed here recently of this, a motorcycle approaches a junction at (NSL road) and a driver reckons he has time to turn into a side road, across the bike's path, before the bike arrives. He even cuts the corner to achieve this. But the bike was travelling at about 100 mph, and the rider is killed when he crashes into the car.
Phatboy317 said:
If everybody drove at a constant speed speed, and people ran into the road at random times without looking, and drivers only ever reacted at the last possible moment to such events, without anticipation, slowing down or any such mitigation, then the number of accidents would increase somewhat if the speed increased,when measured population wide over a long period of time - in the order of many years to decades.
We agree - although it would be fairly instant and wouldn't take years. Why would it take decades for this to materialize?Phatboy317 said:
It would have no measurable effect on an individual's accident risk, and certainly no impact on the probability of any individual event.
And that's where I can't see the logic. We both already accept the number of accidents increase across a population if the speed increases, we only differ in how long the increase takes, but why doesn't that change the situation for an individual? So who is being effected by the increase?Dammit said:
The paragraph in bold is the one I'm struggling with - you would appear to be directly contradicting yourself.
See my reply to Emma TDammit said:
a. Great!
b. No - it applies all the time, in every situation, always.
c. This is true, kind of. Personally I like the idea of having two "superfluous" seconds in every potential crash situation. However, this is, once again, your "if you leave two seconds earlier" theory, wearing a different pair of trousers.
If you have, say, thirty seconds to react, and you only need two seconds, the remaining 28 seconds is neither here nor there.b. No - it applies all the time, in every situation, always.
c. This is true, kind of. Personally I like the idea of having two "superfluous" seconds in every potential crash situation. However, this is, once again, your "if you leave two seconds earlier" theory, wearing a different pair of trousers.
But your argument implicitly includes the superfluous time in the equation.
You have to set boundary conditions, without which the whole argument becomes meaningless.
As for the rest, if you continue to misrepresent what I wrote and attempt to put words into my mouth, then I see little point in continuing to waste my time here.
You're perfectly welcome to do your own research, write your own simulations etc.
vonhosen said:
Because we accept a compromise in the risk/benefit. The speed limit is a part of that compromise.
It's the same reason our emergency services aren't subject to speed limits in some circumstances.
So would most of us agree that things are fine as they are (particularly given that we've got the safest roads in the world) or is it the case that there will never be an end to people wanting to tinker with the compromise we have?It's the same reason our emergency services aren't subject to speed limits in some circumstances.
heebeegeetee said:
vonhosen said:
Because we accept a compromise in the risk/benefit. The speed limit is a part of that compromise.
It's the same reason our emergency services aren't subject to speed limits in some circumstances.
So would most of us agree that things are fine as they are (particularly given that we've got the safest roads in the world) or is it the case that there will never be an end to people wanting to tinker with the compromise we have?It's the same reason our emergency services aren't subject to speed limits in some circumstances.
heebeegeetee said:
vonhosen said:
Because we accept a compromise in the risk/benefit. The speed limit is a part of that compromise.
It's the same reason our emergency services aren't subject to speed limits in some circumstances.
So would we agree that things are fine as they are (particularly given that we've got the safest roads in the world) or is it the case that there will never be an end to people wanting to tinker with the compromise we have?It's the same reason our emergency services aren't subject to speed limits in some circumstances.
Well, if we ignore the "dead people are bad" part, and just look at the economics, we have a negative figure (cost) of 15 billion pounds per year (https://uk.news.yahoo.com/road-accidents-cost-economy-15bn-123622550.html).
That's a fairly large figure, given that we are apparently totally at a loss as to how to find another 8 billion pounds for the NHS right now.
But, if we view that 15 billion cost as "road tax" that we all pay as part of our taxes to enable personal motorised travel as being vital to the economy then we could make an argument for it being needed.
I don't agree, I think that a system that accepts a tithe of almost 2,000 deaths a year has something fundamentally wrong with it, but there you go.
That's a fairly large figure, given that we are apparently totally at a loss as to how to find another 8 billion pounds for the NHS right now.
But, if we view that 15 billion cost as "road tax" that we all pay as part of our taxes to enable personal motorised travel as being vital to the economy then we could make an argument for it being needed.
I don't agree, I think that a system that accepts a tithe of almost 2,000 deaths a year has something fundamentally wrong with it, but there you go.
Edited by Dammit on Sunday 26th October 11:02
The whole idea that accidents are proportional to time travelling betrays a complete lack of understanding of road safety, probability and whatever else.
When driving, and this might come as a shock, you're not the only living actor in a nihilist mechanical circus. YOU have a very significant input into what other people do, so usually, when someone pulls out of a junction it's at least partly related to what YOU have been doing.
Even when the boulder of unstoppable destiny rolls down the mountain roughly into your path, it's not just a case of throwing up your hands and going 'oh well'. What YOU have been doing drives your ability to react accordingly and avoid a collision.
When driving, and this might come as a shock, you're not the only living actor in a nihilist mechanical circus. YOU have a very significant input into what other people do, so usually, when someone pulls out of a junction it's at least partly related to what YOU have been doing.
Even when the boulder of unstoppable destiny rolls down the mountain roughly into your path, it's not just a case of throwing up your hands and going 'oh well'. What YOU have been doing drives your ability to react accordingly and avoid a collision.
Jon1967x said:
And that's where I can't see the logic. We both already accept the number of accidents increase across a population if the speed increases, we only differ in how long the increase takes, but why doesn't that change the situation for an individual? So who is being effected by the increase?
If you buy two lottery tickets a week instead of one you double your chances of winning.But you will probably sill not win the lottery in your lifetime.
So doubling your chances will have made no practical difference to you, as an individual.
Phatboy317 said:
Jon1967x said:
And that's where I can't see the logic. We both already accept the number of accidents increase across a population if the speed increases, we only differ in how long the increase takes, but why doesn't that change the situation for an individual? So who is being effected by the increase?
If you buy two lottery tickets a week instead of one you double your chances of winning.But you will probably sill not win the lottery in your lifetime.
So doubling your chances will have made no practical difference to you, as an individual.
trashbat said:
The whole idea that accidents are proportional to time travelling betrays a complete lack of understanding of road safety, probability and whatever else.
Read it again. You're misrepresenting.trashbat said:
When driving, and this might come as a shock, you're not the only living actor in a nihilist mechanical circus.
Yes, most un-suicidal people will not run into the road when there's a car bearing down on them, and most drivers are observant most of the time.And it's only in the exceptional cases where there has been a breakdown of the above, where a few feet or a fraction of a second can make a difference, it's only in these cases where most of these arguments hold any water whatsoever.
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