Flying Dodo wrote:
I'd agree that shunts are caused by lack of attention, as one car could only go into the back of another because they hadn't realised in time that the car in front had slowed suddenly. However as well as leaving a sufficient gap between vehicles, speed is a factor.
Only if not compensated for by substatnailly increased following distance.
Flying Dodo wrote:
If you had 2 cars in one lane at 50 mph and 10 metres apart and the front one suddenly braked, then there'd be enough time for the car behind to slow.
Let's examine the science here. 50 mph = 24.4 yards (23 m) per sec. I personally think the gap left is insufficient - and would be happier with 2 sec at 50 mph - 45m. Yes on a dry road with good concentration you could pull up - but to do so you would have no "zone of time" to forewarn anyone behind you of the impending calamity.
Flying Dodo wrote:
If they were at 80 mph then there might not be enough of a gap to prevent a shunt.
80 mph = 39 yds (37+ m) per sec. If you are still following at 30m, you have a time zone of only just over 3/4 sec. You are an accident waiting to happen. At higher speeds, the two-second rule is inadequate as braking distance goes up with the square law of the distance or, more importantly, the time taken to stop goes up aproximately linealrly with speed. I would go for 120 - 150 yards at 80 mph. Any closer is inviting heart-throbbing moments at best.
Flying Dodo wrote:
Just as a slight aside, there's also the domino effect, where one car in front touches their brakes for a second, the car behind hits the brakes for 2-3 seconds, the car behind that for 4-5 seconds or more, and then the car behind them, seeing 2 or 3 cars in front suddenly put on their brake lights really hits the brakes and so on. I've seen this happen on the slope up northbound to J9 on the M1 - it was like seeing the tide suddenly rush in, with an accelerating spread of red lights. Often I suspect a shunt would happen 4 or 5 cars back in that sort of situation.
So yes, it does mean drivers have to be intelligent enough to realise at higher speeds you have to leave a bigger gap. It's not just speed in isolation that's the problem, it's a combination of things.
Agreed - but it is not absolute speed that precipitates the domino effect, it is people following too close for the speed at which they are travelling.
Flying Dodo wrote:
People forget that being able to drive is a privilege, not an automatic right, but the fundamental issues of bad driving in any form unfortunately are directly related to the wider social problems in the UK.
Agreed.
Flying Dodo wrote:
For example, I know some people have a go at BMW drivers. It's not the BMW that has the problem, it's the idiot inside. If they were in a Reliant Robin, they can still cut you up.
I think a Reliant Robin would have a job cutting me up on the motorway
Flying Dodo wrote:
So the Government to produce statistics such as these, highlighting shunts at speed are continuing to use speed cameras as a cheap & simple way to try and tackle a much bigger problem, which to be honest, can't be addressed.
Oh yes ity can - but not with cameras. There is much material on here to educate drivers. Education and anticipation are the two keys to avoiding an accident.
Flying Dodo wrote:
It'll help a bit, but it's not the whole answer.
If by "it" you mean cameras... no it won't. They cost lives. They may not increase accident numbers but by heck they do increase the severity of some accidents by their distraction factor.
Edited to add that my post was being composed without knowledge of or reference to Paul's 2 minutes above.