reduce by 1mph...
Discussion
reading thought on pepi... Thames Valley are now claiming something new...
[quote]In order to achieve a real deterrence we have taken a firm, fair and consistent attitude towards enforcing speed limits because we know that reducing speed by just 1 mph can reduce those casualties by as much as 7 percent. [/quote]
must have done new research then... :)
so on a motorway if i reduce my speed from 70 to 20 i'll have reduce casualties by 350% - tis good to know :)
[quote]In order to achieve a real deterrence we have taken a firm, fair and consistent attitude towards enforcing speed limits because we know that reducing speed by just 1 mph can reduce those casualties by as much as 7 percent. [/quote]
must have done new research then... :)
so on a motorway if i reduce my speed from 70 to 20 i'll have reduce casualties by 350% - tis good to know :)
Obviously bollox, but for a laugh, how about speculating from where this berk might have got this 'fact'? Said berk may have noticed that kinetic energy is proportional to the square of velocity and has then decided to use this to compare the kinetic energy of a car travelling at 30mph and 31mph. Said berk has then compared 30 squared and 31 squared and found a 7% difference. 
A little knowledge is dangerous.......
Julian
A little knowledge is dangerous.......
Julian
I'm sure that result is taken at a speed camera site, where drivers would quite obviously slow down. What they won't tell you is the other safety improvements made at that site which is more effective but nothing to do with the camera (pedestrian crossings/barriers etc).
Hence drivers have slowed down and there were fewer accidents, yet there is no actual correlation between the two!
Hence drivers have slowed down and there were fewer accidents, yet there is no actual correlation between the two!
There was a report done many years ago that compared three small accident samples from three different countries several years apart and found that the samples with lower speeds had slightly lower accident statistics. The correlation they came up with was 1 mph slower corresponds to 5% lower accident rates.
The report is scientifically nonesense, the samples are too small to be statistically significant and they have made no attempt to account for the other differences between the environments the samples came from; they did not compare like with like. However, this 1 mph / 5% relationship gets quoted again and again, along with the 1/3 lie.
The report is scientifically nonesense, the samples are too small to be statistically significant and they have made no attempt to account for the other differences between the environments the samples came from; they did not compare like with like. However, this 1 mph / 5% relationship gets quoted again and again, along with the 1/3 lie.
julianc said:
Obviously bollox, but for a laugh, how about speculating from where this berk might have got this 'fact'? Said berk may have noticed that kinetic energy is proportional to the square of velocity and has then decided to use this to compare the kinetic energy of a car travelling at 30mph and 31mph. Said berk has then compared 30 squared and 31 squared and found a 7% difference.
A little knowledge is dangerous.......
Julian
Genius. 6.3% - rounded up to 7% for expediency?
Is there any relationship between free travelling speed and impact speed?
kevinday said:
Genius. 6.3% - rounded up to 7% for expediency?
The 6.7% works by saying "Energy is proportional to the square of the speed, so if we increase the speed from 30 to 31 that raises the energy by 6.7%." To get to the statement given, you then have to flunk maths again by saying that the 6.7% increase means that reducing speed by 1mph reduces energy (and thus casualties) by 6.7%.
If you are hit at 29 mph it hurts a lot! If you are hit at 30 mph - it still hurts a lot!
It depend where you are hit as to what happens und many children have been killed in driveway when parent fail to check geat in neutral or leaves handbrake off or badly serviced car's hand brake ist not tightened und fails. Ist slowest speed - but bumper contacted at wrong place und cause tragedy.
Road safety ist about observing common sense of POWER checks und COAST driving principles. Ist simple!
It depend where you are hit as to what happens und many children have been killed in driveway when parent fail to check geat in neutral or leaves handbrake off or badly serviced car's hand brake ist not tightened und fails. Ist slowest speed - but bumper contacted at wrong place und cause tragedy.
Road safety ist about observing common sense of POWER checks und COAST driving principles. Ist simple!
V8 Archie said:
Genius. 6.3% - rounded up to 7% for expediency?
I make it 6.7% myself...
Ahha.... well that will depend on whether you divide 900 by 961, or 961 by 900.........
The 6.7% works by saying "Energy is proportional to the square of the speed, so if we increase the speed from 30 to 31 that raises the energy by 6.7%." To get to the statement given, you then have to flunk maths again by saying that the 6.7% increase means that reducing speed by 1mph reduces energy (and thus casualties) by 6.7%.
If you state it as a reduction then you need to take the higher value as your denominator. If you state it as an increase, then you need the lower value.
So it's a 6.3% decrease per mph and a 6.7% increase.
Or a 7% fudge of the physics.
woodytvr said:
POWER?
COAST?
Petrol (or derv)
Oil (ist self explained
) Water (radiator/screen wash etc)
Electrics (lights/washer button works/ etc)
Rubber (tyres/wiper blades)
C oncentration (also Courtesy/Consideration}
O bservation
A nticipation
S pace
T ime
Und my cousin made post about this on Paulie's site -
www.safespeed.org.uk/forum/viewtopic.php?p=41105&highlight=#41105
Und the proof it ist "official"
www.safespeed.org.uk/forum/viewtopic.php?t=4239
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