Safe Speed Forums

Having reviewed the updated BBC video as carefully as I can, I note considerable damage on the nearside of the car, especially toward the front.

I suggest that the crash started with a little bit of oversteer. Opposite lock was applied but the power stayed on. The lock caught the slide, but because the power was still on and the opposite lock remained a vicious secondary skid left the car spinning clockwise (from above) across the road. The nearside connected with the cyclists and the vehicle continued to hit the wall on the right. Somewhere around the front nearside corner contacted the wall and the car bounced off spinning another 135 degrees clockwise as it recrossed the road before coming to rest with its nose on the left verge.

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Paul Smith
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I was thinking similar but that instead of opposite locking he just locked up, with the C of G of the car going in a staight line toward the cyclist but spinnig (fairly slowly) about its own axis throughout, with the front nearside happening to be the bit that caught the bikers. Having re-reviewed the video though I think your explanation may be the more likely.

An anonymous poster felt it important to comment on this and submitted the following via the anonymous forum:



I feel that in context, the original statement was reasonable. Many have described the road as 'dangerous'. We must explore all the causation factors so that we can understand how such tragedies can be avoided in the future. I don't believe that Ernest was apportioning blame, I think he was exploring possible responsibilities. I can see room for misinterpretation however.

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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

no, that's what all bike crashes end up looking like as the back of the bunch rides into the front.



don't forget that corollas are fwd.

Yes - but get new tyres on the front and old on the back.... My first accord was shod with Mich XZXs. These weren't available when the fronts wore down so I got MXs. I loved it - made it like a racing car, but I had to put the MXs on the back otherweise I know it would not have survived with my other half at the wheel.

I confess I don't know how you put a FWD into a secondary skid. Any FWD fans around?

What to do you have to do to achieve the scandanavian flick in a FWD car? Is it just on lift-off under low grip conditions? If so it's even more likely.

I'm much more used to 'controlling the pendulum' with the throttle - power to break traction, lift to slow the swing.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
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sorry, didn't mean that you couldn't lose the back but that keeping the power on would have a different effect.



isn't stomping the brake with the left foot the approved rally method?

Maybe in high grip conditions (at least relative to ice).

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
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On a snowy/icy road you can do it with just a tiny jerk on the handbrake. Lift off and it makes it worse - and fishtails.

To do it on a better road you need to use the handbrake with greater brutality - or simply have a flat rear tyre, that does it.

Agreed, although I wouldn't rate using the handbrake as a likely component of this horrible crash. An unfortunate combination of throttle (and possible brake) with slow steering and low grip is all it will have taken.

It also looks as if most of the speed remained at (initial) impact, which is further evidence of very low grip. Sliding sideways scrubs off speed fast in normal grip conditions.

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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

You can get a secondary skid in a fwd car if you over correct at speed, I started one after corning wayyy too fast once.

I'd imagine the corolla driver over corrected, panicked and hit the brakes which would probably have flipped the car round. I also notice white painted lines on that corner, they are much more slippy than tarmac so a front wheel on those might have made the whole thing more unpredicatable.

Braking in a non abs car with one side on good grip and one side on bad grip will turn it round if any lock is a applied and can turn it round if the driver isn't expecting that to happen. If he/she had skidded then braked that may have been just enough to flip him/her round, send them backwards to the wall and ping back off into the other side of the road where they ended up.

Often, simply backing off the throttle on a slippery surface (even a damp road) is enough to make a FWD tailslide. If is was a small patch of ice it's possible the driver reacted to the front wheels hitting it by backing off (which would be the correct way to deal with the understeer) and caught the rears on the ice.

Once you do get a FWD tail out it can be very difficult to bring it back. Often the only method is to apply opposite lock and power to drag the nose back in front of the rear. I have succesfully done this on a couple of occasions but it's a bit hairy to say the least and involves a good deal of travelling in the direction the car wants to go.

I have also spun a FWD car on a slippery road at fairly low speed (under 40mph). You'll find it happens very quickly when it goes and can take a long time to come to a halt.

This is such a tragedy, and like every other, completely avoidable.

but I wouldn't like to offer any 'professional' opinion in public as to what was the primary cause of this collision, at least not until full investigation has taken place.

Unlike this comment.


Looks like the investigation is over and done. The defence has already been provided to the Corolla driver, and supported by police!

I can't imagine how this will make the cyclists' families feel.

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Fixed ideas are like cramp, for instance in the foot, yet the best remedy is to step on them.

Ian

I couldn't agree more. The only explanation I have for the behaviour of NWP is that they are trying to deflect responsibility because they failed in their duty to mark or treat something that they knew to be dangerous.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
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Regarding the specifics of this accident I too will reserve any judgement, on the grounds that we don't have the necessary facts upon which to base any meaningful analysis. I too am mightily suspicious of NWP's motives in dismissing it as "just one of those things", four people are dead here and this needs to be looked into in great detail to help prevent it happening again. And the inescapable implication of their words seems to be that the drivers who obey the speed limit are therefore automatically blameless in any accident. To me that sums up the very worst aspects of current road safety thinking, and everything we are opposed to here.

On the FWD / RWD thing, Homer has it bang on. In low grip conditions many nimble FWD cars will reward the driver who lifts off with savage oversteer. Indeed, this is a standard cornering technique for FWD cars in rallying, where a brief lift off phase is used to unstick the car and make it turn into a corner, with the power being re-applied promptly to correct the weight transfer and prevent the slide from progressing further. If you fail to put the power back on in such a situation then the car will continue to oversteer very quickly indeed - in all likelyhood faster than can be corrected simply by applying opposite lock alone. A classic scenario is where the corner unexpectedly tightens and all is initially well as the driver backs off further and turns in, except that he is now in too high a gear and can't apply sufficient power to collect things back up again, so exits the corner facing the wrong way!

In some ways FWD cars can actually be more unstable than supposedly tail-happy RWD ones, partly as the latter have usually had a lot more effort put into the suspension design specifically to limit and control oversteer, but mainly because FWD cars have a much more forward weight distribution and thus the unloading of mass from the rear tyres in a "lift-off" situation is more marked.

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SafeSpeed, what has happened to your objectivity. Normally I have the utmost respect for your views and arguments but in this case you seem determined to find a way to blame NWP for this incident.

Maybe the police had requested a gritter after the 9a.m. accident but this accident only happened just after 10 so it is possible that gritter just did not get there in time.

It is also possible that the reason it was so slippery is that the ice had begun to melt and formed a layer of water over the ice. This can happen very quickly as the sun warms the surface and then half an hour later the ice could be gone.

The BBC and the Scotsman are both reporting that police attended an accident caused by ice in the same location an hour earlier. If they did THERE IS NO EXCUSE for walking away from a road in an extremely dangerous condition.

I don't see this as an 'objectivity failure', although I confess to being angry about the tragedy. See:
http://news.scotsman.com/index.cfm?id=34462006

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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

Do you actually know that NWP did nothing and walked away?

Closing the road may have been cosidered but rejected becuase the alternative route might have been untreated minor roads, which would have been much more hazardous.

There was only an hour between the incidents which is really not long to solve the problem with gritters and you know as well as I do that the Police can put out as many signs as they like and some people will still not slow down.

But the Police clearly stated that the driver's speed was not excessive, which they surely would not have said had they taken steps to warn drivers of the extreme hazard at that specific point in the road.

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Did you see the Safe Speed PR? http://groups.yahoo.com/group/SafeSpeedPR/message/125

The tone is questioning. And yes, 'reports' do indicate that the Police walked away. We can't know that the reports are true, which is why I've called for an investigation.

If I'd found such ice, as a private motorist, I would have waited at the scene warning traffic. Indeed, that's exactly what I did do when I found such ice. When the Police showed up they took on the job of warning traffic pending the arrival of gritters (I assume).

I think putting up signs would have been a weak response (but at least it would have been a response), but no one has reported or photographed signs. And I've now seen plenty of film of the location. I'm confident that if warning signs had been present they would have been filmed.

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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