Omega Owners Forum
Chat Area => General Discussion Area => Topic started by: Auto Addict on 06 June 2008, 07:53:31
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Collision Speeds
(Figures From The Thames Valley Police Accident Investigation Team)
Vehicle “A” is travelling at 30mph in a built up area, a child steps into the road and the driver manages to stop just before hitting him.
Vehicle “B” is travelling at 32mph, in exactly the same situation the vehicle will hit that child at 11mph.
At 40mph - 26mph
At 50mph - 40mph
Vehicle “A” is now travelling at 40mph on a road of that speed limit, a vehicle pulls out of a junction and the driver just manages to stop before hitting it.
Vehicle ”B” is travelling at 60mph, in exactly the same situation, he will hit that vehicle travelling at 45mph.
Vehicle “A” is now travelling on a Motorway at 70mph, for no apparent reason the traffic is stationary ahead of him, he just manages to stop before ploughing into the back of the vehicle ahead.
Vehicle “B” is travelling at 80mph, in exactly the same situation he will hit the vehicle ahead at 38mph.
At 90mph - 57mph
At 100mph - 71mph
Is this starting to build a picture? At the higher speed in each situation vehicle “B” is colliding at a speed greater than the maximum limit he should be driving at.
Makes you think doesn’t it?
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well thats just opened my eyes a bit. shows speeding just aint worth it.
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I am getting in the A car they have better brakes :P
seriously though it does make you think
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"Vehicle “A” is now travelling on a Motorway at 70mph, for no apparent reason the traffic is stationary ahead of him, he just manages to stop before ploughing into the back of the vehicle ahead."
I'm not endorsing speeding, but if Driver A "only just manages to stop", regardless of the speed limit, he was driving too fast for the conditions.
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"Vehicle “A” is now travelling on a Motorway at 70mph, for no apparent reason the traffic is stationary ahead of him, he just manages to stop before ploughing into the back of the vehicle ahead."
I'm not endorsing speeding, but if Driver A "only just manages to stop", regardless of the speed limit, he was driving too fast for the conditions.
...but at least he stopped.....
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"Vehicle “A” is now travelling on a Motorway at 70mph, for no apparent reason the traffic is stationary ahead of him, he just manages to stop before ploughing into the back of the vehicle ahead."
I'm not endorsing speeding, but if Driver A "only just manages to stop", regardless of the speed limit, he was driving too fast for the conditions.
Missing the point somewhat I believe... :(
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Statistics can prove anything....
If you lie with your head in the freezer, and your feet in the oven....
On average you will be pretty comfortable ;D
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Statistics can prove anything....
If you lie with your head in the freezer, and your feet in the oven....
On average you will be pretty comfortable ;D
Try it the other way round then :)
But I think you'll find these are facts.....
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"Vehicle “A” is now travelling on a Motorway at 70mph, for no apparent reason the traffic is stationary ahead of him, he just manages to stop before ploughing into the back of the vehicle ahead."
I'm not endorsing speeding, but if Driver A "only just manages to stop", regardless of the speed limit, he was driving too fast for the conditions.
Missing the point somewhat I believe... :(
I'm not missing the point - I fully understand the difference between colliding with a stationary object and not colliding with it. Not colliding with it is usually the better option. Adjusting speed to avoid collisions works quite well.
And if Driver A "only just manages to stop", there's a good chance that some buffoon behind him won't, with the result that he hits the car in front at whatever speed results from the second collision.
These are good statistics, but not in themselves a valid reason for blindly obeying speed limits. Driving at 70mph on a motorway doesn't absolve you from blame if there is a collision. Especially if the conditions indicate that a more sensible speed would have been 50mph.
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is it true that braking/stopping distances are still based on old cars or have they now been re-calculated to allow for newer cars with better braking systems ( abs, discs etc etc ) just curious
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I think the example nicely illustrates the newtonian aspect of braking.
E=1/2mv2
Assuming a constant braking force distance is proportional to speed squared!
In practice both drivers were being reckless. Driver "A" would have got some nasty surprises if it were raining, there were a pot hole in his braking area (not on our wonderful roads - a purely hypothetical situation!) or his reaction time was a few milliseconds longer.
In fact, due the the fact the so much of his speed clearly disappeared within the last metres of braking I wouldn't vouch for the condition of his underwear!
Kevin
Kevin
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Damn! That echo's back. >:(
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is it true that braking/stopping distances are still based on old cars or have they now been re-calculated to allow for newer cars with better braking systems ( abs, discs etc etc ) just curious
I keep meaning to try some real stopping distances using my AP22 datalogger - on my private test track, of course. ;)
Kevin
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Yes, a classic example of how statistics can create a picture.
Consider if the person traveling at 30mph had braked 1 second later due to being on a mobile......
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Yes, a classic example of how statistics can create a picture.
Consider if the person traveling at 30mph had braked 1 second later due to being on a mobile......
Absolutely! I'm afraid I was jumping ahead a bit. These are excellent statistics, and they make me think - they should make everybody think.
But I can't read anything like that without automatically seeing the words "Speed Kills" appearing next.
Stupidity kills. Carelessness kills. Speed turns an injury to a fatality, or a bad scare to an injury. Driving too fast for the conditions is either careless or stupid.
Rant over :(
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Also, it is worth remembering that the legal speed limit is there as the maximum permissible speed, but you could still be prosecuted for driving at a speed too high for the road condition even when travelling at under the speed limit.
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And, the statistics also show that it is worth keeping a safe distance from the vehicle in front of you, and even more so when driving on motorways.
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is it true that braking/stopping distances are still based on old cars or have they now been re-calculated to allow for newer cars with better braking systems ( abs, discs etc etc ) just curious
I keep meaning to try some real stopping distances using my AP22 datalogger - on my private test track, of course. ;)
Kevin
sounds like an experiment in the offing. if you need an assistant or somebody to hold the camera let me know. wouldnt mind a go on your private test track ;) ;) ;D
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sounds like an experiment in the offing. if you need an assistant or somebody to hold the camera let me know. wouldnt mind a go on your private test track ;) ;) ;D
Ahem.. No problem. [size=8]Don't forget your tax disk[/size] ::)
Whilst it makes a valid point I hate the way these examples are always adjusted so that everything's roses for someone travelling at exactly the speed limit but it all turns to sh!t a small margin above.
IMO, it's not relevant whether you're at, a few percent above or below the limit that matters but whether your attention is focussed on observing the road conditions ahead and adjusting your speed accordingly or on driving at precisely the speed limit.
Kevin
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I think what I am saying is that stupidity and due car and attention or the main problems.......speed is a factor but, you could be traveling at 10mph in a 30 in your chelsea tractor and still hit somebody if distracted...
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Remember that the stats/sums quoted are hypothetical calculations not 'real' examples and are simply to get a point across..... :y
Its similar to being able to calculate the maximum speed for a bend where any faster and the car becomes unstable.
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Collision Speeds
(Figures From The Thames Valley Police Accident Investigation Team)
Vehicle “A” is travelling at 30mph in a built up area, a child steps into the road and the driver manages to stop just before hitting him.Vehicle “B” is travelling at 32mph, in exactly the same situation the vehicle will hit that child at 11mph.
At 40mph - 26mph
At 50mph - 40mph
Vehicle “A” is now travelling at 40mph on a road of that speed limit, a vehicle pulls out of a junction and the driver just manages to stop before hitting it.Vehicle ”B” is travelling at 60mph, in exactly the same situation, he will hit that vehicle travelling at 45mph.
Vehicle “A” is now travelling on a Motorway at 70mph, for no apparent reason the traffic is stationary ahead of him, he just manages to stop before ploughing into the back of the vehicle ahead.
Vehicle “B” is travelling at 80mph, in exactly the same situation he will hit the vehicle ahead at 38mph.
At 90mph - 57mph
At 100mph - 71mph
Is this starting to build a picture? At the higher speed in each situation vehicle “B” is colliding at a speed greater than the maximum limit he should be driving at.
Makes you think doesn’t it?
Makes me think the stats are either unclear or wrong :-/
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I think what is missing from the "Vehicle A is travelling at...." scenarios is the vital phrase (and one which is always included when these test results are reported by those responsible for conducting them) is "all other factors being equal". In reality, "all other factors" will never be equal. Numpty driver in Vehicle A, who has his brakes serviced by Qwik-Fitt Spanner-Monkey who used cheap parts and didn't give a monkey's uncle about the quality of his work, is going to produce different results than a driver in Vehicle A.1 who uses the best brake parts he can reasonably afford and competently fits them himself, doing a top job in the process. So if Vehicle A has so many variables (because, once again, "all other factors" will never be equal), then the result can't even be compared properly to Vehicle A.1, let alone Vehicle A at 30MPH and Vehicle B at 40 MPH etc etc.
In a nutshell, just as the safety gained by the 10MPH reduction in speed can be lost easilly by other factors (tyres, brakes, shocks, driver skill, driver awareness at that precise moment in time), the safety lost by driving 10MPH faster can be regained by other factors - good brakes, good driver, etc etc.
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So all things being equal, traveling at 40mph in the same conditions under the same distances and circumstances, the driver would avoid the car but not the kid?
Obviously it's his neighbor’s chavy kid who keyed his car last week and this is his act of vengeance