Just goes to show the 2 second rule sometimes isn't enough to avoid an accident.
www.youtube.com/watch?v=t0dkObmgH28
And look how close white van man is to hitting the car that suddenly swerves in front of him. His reactions were obviously quicker than the driver with the dash cam.
And typical of the lorry (with the mobile home on the trailer) trying to overtake the other lorry in lane one, and taking an absolute age to do it.
|
I couldn't see a 2 second gap. He was less than 1 second behind the car that he was following.
Mind you, that's quite a lot of idiots in just one small area of motorway.
|
|
I was using the vehicles in lane 2 as a marker for the 2 second gap. Between the car in front of him, and when he then overtook them, I made it almost 3 seconds.
Last edited by: VxFan on Mon 26 Sep 16 at 01:36
|
But the cars in lane 2 were moving as well!
Use the white line dashes as the front car passes them and count until the camera car passes the same dash. I think you will find it less than 1 second.
|
At the start of the clip, dash cam driver is much to close for comfort however the Skoda seems to accelerate up to the accident much quicker (Around 00:10) of which dash cam driver doesn't try to make up the gap.
My thoughts were that he got caught up in an unfortunate situation, which Skoda driver caused.
The gap looked ok to me just prior to the skoda swerving
Did well to avoid serious injury to the Polo driver which was virtually at standstill.
Megane driver looks a little shocked!
|
>> My thoughts were that he got caught up in an unfortunate situation, which Skoda driver
>> caused.
>>
>> The gap looked ok to me just prior to the skoda swerving
Rule 126 of The Highway Code:-
"Remember what your granny told you - Always drive at such a speed that you can stop within the distance that you can see to be clear".
Rule 126."Stopping Distances. Drive at a speed that will allow you to stop well within the distance you can see to be clear.
You should leave enough space between you and the vehicle in front so that you can pull up safely if it suddenly slows down or stops. The safe rule is never to get closer than the overall stopping distance. Allow at least a two-second gap between you and the vehicle in front on roads carrying faster-moving traffic and in tunnels where visibility is reduced. The gap should be at least doubled on wet roads and increased still further on icy roads remember, large vehicles and motorcycles need a greater distance to stop. If driving a large vehicle in a tunnel, you should allow a four-second gap between you and the vehicle in front".
Anyway, we did all this the other day in another thread.
|
>>which Skoda driver caused
Affirmative.
|
Looks to me like Megane man, finally exiting the car, is quite careful to make sure he doesn't scratch his door on the crash barrier....
For once I don't see a particular lane 3 lemmings problem with those involved , the driver of the dashcam car seemed about to move back in when the white van stymied that move, though the fact that the traffic is stationary in lane three when lanes 1 and 2 have space does prove something I guess - the lemmings are all parked up in lane 3 for once, and therefore previously there must have been a greater volume of traffic in that lane.
|
>> >>which Skoda driver caused
>>
>> Affirmative.
>>
Nonsense!
Dash Cam man dunnit.
Anyway, I am off to Wales now.
|
|
Car with dash cam seemed to have a reasonable gap to the car in front, to me anyway, i guess the skoda driver somehow missed a lane of standing traffic. I'd say that alone makes it the skoda drivers fault.
|
>> Car with dash cam seemed to have a reasonable gap to the car in front,
>> to me anyway, i guess the skoda driver somehow missed a lane of standing traffic.
>> I'd say that alone makes it the skoda drivers fault.
Typically a dash cam has a wide angle of view and on playback, as with convex mirrors, "objects are closer than they appear".
As NoFM said, there's less than a second of separation in front of dashcam man (or woman). Add to that the fact that the driver must have been looking solely at the car in front rather than further down the road, and you have the essential ingredients for a crash if things go wrong - which they did.
Dashcam man was responsible for his own crash. Skoda? man didn't brake for very long before clipping the back of the almost stationary queue so he must have been distracted too.
|
Always important to remember that all lanes on a motorway many not be travelling at the same speed, or at any speed!
www.youtube.com/watch?v=6-0E2Nxtm6o
|
|
Always amazes me how late some people will leave it to get from the outside lane to inside to come off at a junction. Maybe because they mistimed it or are risk takers most of the time. If you can't safely get across the lanes then carry on to the next junction.
|
>> >> Car with dash cam seemed to have a reasonable gap Typically a dash cam has a wide angle of view and on playback, as with
>> convex mirrors, "objects are closer than they appear".
i think you must be right, the camera must be deciving in some way. Looks fine to me, but the consensus on here says otherwise, so I'll go with that.
|
>> Just saying :-)
Well if you will go hiding it in another thread, and use a Daily Wail link, how do you expect me to find it using a forum search to see if it had already been posted ;)
>> But the cars in lane 2 were moving as well!
Yeah, I realised my schoolboy error this morning. My only excuse was it was late when I mentioned it
Last edited by: VxFan on Mon 26 Sep 16 at 10:23
|
So the "BMW" in front is actually a Skoda!
Does seem a bit unfortunate, you can see the Polo's hazards are flashing vigorously - not sure if that was because it had basically just done an emergency stop (and has emergency brake assist) or were they triggered after the Skoda hit it.
Dash cam driver has to take responsibility for his own actions (or lack of) but he probably thought he was following at a safe, steady pace. But it was the Skoda driver that wasn't paying attention to the slowing traffic in front for whatever reason and just realised at last minute.
Poor Megane driver - that's the new shape, am sure its only been out a couple of months in this country!
Didn't seem to be any evidence of any airbags going off in camera car which I would have thought would have been the case at that speed?
|
Dashcam man solely to blame for crash.
Dozy Skoda driver responsible for his own brown trousers and those of the fortuitously quick on the draw WVM.
Dash and Skoda both pelting along focussed on only the car immediately in front. Dash far too close to Skoda. More attention to what's happening in the whole of the quarter/half mile ahead and both would have seen brake lights sooner.
The elephant racing lorries are a red herring. They shouldn't do it but it's prevalent and nobody is forced to deal with it by going nose>tail in lane 3. Better mitigation is to ease off and stay behind until there's opportunity to use lane 3 with adequate margins.
|
> on the draw WVM.
What does that acronym mean?
|
This accident was an example where a self-driving car would be unlikely to have avoided it because it would not have seen the queue ahead of the Skoda driver. Also radar cruise-control/auto brake would have caught out too.
You have to be keeping an eye on the traffic situation further up the road.
|
>> This accident was an example where a self-driving car would be unlikely to have avoided
>> it because it would not have seen the queue ahead of the Skoda driver. Also
>> radar cruise-control/auto brake would have caught out too.
>>
Talk to those nice Nissan people ?
www.nissan-global.com/EN/TECHNOLOGY/OVERVIEW/predictive.html
|
>>This accident was an example where a self-driving car would be unlikely to have avoided it
I disagree.
>> because it would not have seen the queue ahead of the Skoda driver.
Not relevant in the slightest. The automated car would have been, as the cam driver should have been, driving within the limitations of the pace it could see to be clear and at the correct minimum distance back from the car in front.
I should think it would be damn near 100% likely to avoid the accident given how b***** obvious the risks were.
|
>>given how b***** obvious the risks were.
And how easily avoidable.
|
>> >>given how b***** obvious the risks were.
>>
>> And how easily avoidable.
>>
And a reason I hate driving behind something I can't see through or around, and try to avoid not being able to see a long way ahead.
|
We disagree about how technology for self driving cars could avoid this (next ten stuff like inter-car communication on the other hand would have helped).
The auto cruise control/brake could have kept a safe distance from the Skoda. But the Skoda got dangerously close to the the stationary queue and then quickly changed lanes (clipping the Polo).
To avoid this the dash cam driver needed to be looking much further ahead. And like said I dislike following something I cannot see past and therefore take this into account.
|
You are supposed to be able to stop in the distance that you can see to be safe. Why is that difficult for technology?
The car was less than 1 second behind the lead car - which is pretty f. stupid. Technology would not have made that error, and therefore would have stopped long before the cam car did.
|
What is really worrying is that on this forum, which is mostly supported by intelligent people with an interest in motoring, experience thro age, and a generally responsible attitude, how many have posted on this thread perceiving that the dash camera driver was at a suitable distance. It is therefore somewhat surprising that that the accident rate resulting from inappropriate following is not even higher.
Probably the rate at which technology has improved braking and handling , means that misjudgement incidents of yesteryear now generally avoid metal to metal contact. It goes someway to explain the frequent bunching/stationary episodes that are seen on a regular basis on heavily congested motorways.
|
>>What is really worrying is that on this forum, which is mostly supported by intelligent people with an interest in motoring, experience thro age, and a generally responsible attitude, how many have posted on this thread perceiving that the dash camera driver was at a suitable distance.
I think that is mainly due to the illusion created by the wide field of view. It didn't look so bad to me until I counted the time separation; and I know what 2 seconds+ looks like at 70mph.
Even 2 seconds at 70mph is not enough if you cannot see further than the vehicle in front, and that vehicle either stops instantly or as in this case jinks away and reveals a stationary queue (almost stationary anyway).
By my schoolboy calculations a 1g acceleration of -32f/s^2 while braking (a brave assumption I think) would stop you in 1.6s. Add 0.5 seconds reaction/thinking time and another 0.5 second to move foot to brake and actuate full braking, and it's 2.6s. Andy Green with his nerves twanging could probably achieve that. I doubt if I could.
Make that 0.8g and a total of 1.5 seconds to get to get full brakes on, and you need 3.5s to stop, touching the bumper of the stationary vehicle. And you'd have to be properly on the ball and know how to brake to achieve that.
Incidentally, while everybody thinks that the Highway Code stopping distances are too long, the 'thinking' time they use is only about 2/3 of a second. Given that presumably includes actually shifting the foot from accelerator to brake and pressing it, it's unrealistically short.
Also, working backwards shows that the coefficient of friction implied by the HC in the stopping distances is about 0.7, giving a maximum decel of 0.7g (without aerodynamic downforce). That also sounds optimistic to me as an average; even when it isn't actually raining, road surfaces can be damp/oily/muddy, and of course to get a decel of 0.7g on a surface with a CoF of 0.7 you would need to be braking optimally (easier with ABS if the driver is capable of hitting the pedal hard with confidence - most probably aren't).
Bung in a CoF and decel rate of say 0.5/0.5g, and a more realistic thinking+foot-moving time of 1.5s, and I reckon the HC total stopping distance at 70mph should be more like 500 feet in round numbers than the 315 feet it uses. The implied separation distance of 3.1s using HC assumptions should be nearer 4.7s.
Maintaining such a long separation time could be frustrating, because prattish people think you aren't making progress if you aren't up the chuff of the car in front. Looking down the road mitigates that to a considerable degree, along with other available cues, and must account for the fact that the M1 is not permanently blocked by wrecked vehicles.
I must have a look to see what Roadcraft says about it.
|
>> I must have a look to see what Roadcraft says about it.
Roadcraft goes with the Highway Code, although it does say "at least" two seconds, and "at least doubled" in wet weather.
Probably as much as could reasonably be asked of most people, and it would I suppose be a big improvement on what many actually do.
|
By my schoolboy calculations a 1g acceleration of -32f/s^2 while braking (a brave assumption I think) would stop you in 1.6s. Add 0.5 seconds reaction/thinking time and another 0.5 second to move foot to brake and actuate full braking, and it's 2.6s. Andy Green with his nerves twanging could probably achieve that. I doubt if I could.
A sub 30 year old racer is likely to have the best reactions. While I didn't race others, I raced the clock (hillclimbs and sprints) and got 0.2 on a tester belonging to Grampian Police. The time from accelerator to brake will be hindered by the present practice of having the brake pedal significantly higher than the accelerator thus requiring a leg lift as well as a foot swivel. I took a lot of care in setting up the Morgan, and had the pedals such that one could transfer to other very quickly with the bare minimum of movement. I've a feeling the police tester may have required you to to press an 'accelerator' then move to the left for a brake - so reaction AND move together. But it was thirty years ago, so memory might be playing tricks...
However, the police told me, they regard 1 second reaction time as quite typical, so goodness knows how long the reaction could take before they took note.
|
how
>> many have posted on this thread perceiving that the dash camera driver was at a
>> suitable distance.
One of them was me, i looked at the video on my phone. I couldn't be bothered to turn on my laptop. The skoda looks pretty far away when I watched it.
|
>> One of them was me, i looked at the video on my phone. I couldn't
>> be bothered to turn on my laptop. The skoda looks pretty far away when I
>> watched it.
It still looks pretty far away on a laptop.
As somebody pointed out the nature of camera's lens means things look further away then they are. If you use the lane markings as a reverence it's clear that dashcam is barely a second behind.
|
Interested in how that would work NFM2R - assume technology is bouncing beams off the car in front and knows that the car can't stop instantly in its tracks. But if car does what the Skoda does, it is then faced with a stationery object.
How does a self drive type car get information from the vehicles in front of the Skoda?
Would the two second rule be enough to let you react if the car in front of you stopped instantly which is, in effect what you are faced with here?
Reminds me of my brother having a shunt many years ago in his Orion and blamed the driver of the car he hit, a Citroen BX I think, because he said the Citroen had ABS and had stopped far quicker than it needed to!
|
The trouble with adaptive cruise control - leave the right gap and I'm sure you'll end up withers moving into your braking zone pretty quickly.
All too often I see drivers in the outside lane driving far too close with little chance of stopping if there is a problem ahead. So when they start doing that I'll drop into the middle lane even if it's going a lot slower.
I don't think the two second rule would have helped in this instance. The dash cam driver should have observed the stationary cars ahead.
Last edited by: rtj70 on Mon 26 Sep 16 at 17:22
|
>>I don't think the two second rule would have helped in this instance
Wild ass guessery follows;
Cam car was less than 1 second behind lead car, which seemed to be about 4 white line dashes and thus about 5 car lengths.
Cam car overshot the head of the queue by about 3 car lengths and hit another car., though seemingly not particularly hard in the scheme of things.
Cam car had only 4 car lengths to brake in before the queue began and seemingly needed more than 7.
Had the cam car been traveling the correct distance behind the lead car he would have had at least 9 car lengths before the first car, and 12 before the car he actually hit.
Now, if you can stomach that level of guessery I think it is reasonable to think that the accident would have been avoided had he been following the 2 second rule, though perhaps not the brown trousers.
Last edited by: No FM2R on Mon 26 Sep 16 at 17:48
|
>> Now, if you can stomach that level of guessery I think it is reasonable to
>> think that the accident would have been avoided had he been following the 2 second
>> rule, though perhaps not the brown trousers.
See above - my guessery suggests not.
Another way of triangulating that is just to take the Highway Code total stopping distance of 315 feet. That is c. 20 car lengths, and as reasoned above I think it is optimistic (especially for a driver with foot on accelerator and mind on other things).
|
>> Reminds me of my brother having a shunt many years ago in his Orion and
>> blamed the driver of the car he hit, a Citroen BX I think, because he
>> said the Citroen had ABS and had stopped far quicker than it needed to!
The brakes on the BX were powered by the same hydraulic system as the suspension. They required very little pedal force compared to the servo assist or even unassisted brakes then common. Later models had a modified brake control valve to provide more graduation in operation.
|
>> Dash and Skoda both pelting along focussed on only the car immediately in front.
>> Dash far too close to Skoda. More attention to what's happening in the whole of the
>> quarter/half mile ahead and both would have seen brake lights sooner.
>>
>> The elephant racing lorries are a red herring. They shouldn't do it but it's prevalent
>> and nobody is forced to deal with it by going nose to tail in lane 3.
>>
IMO the elephants ARE the key to this IF you are looking ahead.
Then it is B obvious that two lanes are in effect out of action so lets all or at least most of us
all squeeze into lane 3.
>> Better mitigation is to ease off and stay behind until there's opportunity to use lane 3
>> with adequate margins.
>>
Of course, in an ideal world, but in reality you will ease back until the elephant race is over
so it is squeeze and try to make space but an undertaker may jump in front of you etc. etc.
|
|
Whatever driver A or driver B in front of you may or may not have done if you rear end a stationary vehicle you are responsible for your own accident. The dashcam man was within a second of the car in front as has been pointed out, and the two second rule is the MINIMUM following distance, if you can only see the back of the car in front you should increase the gap.
|
I watched this a few times. The dash cam does not show a view of the cars in front of the Skoda. Therefore much too close.
... and I see people drive even closer 'in formation' on the M6.
A comment above about so many idiots - or words to that effect - in one place. Accidents often happen between junctions 14 and 17 on the M6.... I wonder if this accident happened between these junctions?
|
I am surprised the inevitable crash was not too severe. Luckily he missed the first two cars whilst he was probably braking very hard.
Thankfully nobody seemed to have been injured.
|
|
I copied the clip to an editor, and using a fixed point on the road car B was following car A by 1 second.
|
|
And had he had twice the distance (2 seconds) he would have stopped before the queue.
|
|
If he was not as close, he should have seem the queue too. I say he, but we all know it's probably a he.
Last edited by: rtj70 on Mon 26 Sep 16 at 19:17
|
>>And had he had twice the distance (2 seconds) he would have stopped before the queue.
Just about, possibly I think, as the queue was still moving forward. The 'Skoda' swerved about two seconds before dashcam reached the Polo, and it was another second/second and a half before he stopped with the assistance of the Megane.
Last edited by: Manatee on Mon 26 Sep 16 at 19:18
|
|
And so a self driven car which would not have the same thinking amd reaction times would be even more likely to have made it.
|
>> And so a self driven car which would not have the same thinking amd reaction
>> times would be even more likely to have made it.
Probably, yes. Unless it misread the situation, in which case the result might be worse:)
|
So as long as it wasn't a Telsa then.
I see the radar on Tesla's will soon be used as the main source of info for this sort of thing. They currently use cameras with the radar info as additional info. Stupid design decision that if you ask me.
|
It amazes me how many drivers don't look ahead and fix only on the car ahead. If you can't see beyond the car in front you have to leave a bigger than 2 second gap.
I also think the white van, whilst not responsible, is not driving aware of his surroundings. He had a clear view of that whole lane 3 of traffic and if he was looking would have seen sharp braking. Knowing that he should expect the possibility that someone from lane 3 might dive out into lane 2 thus he should have slowed down and stayed in lane 1 until he had passed the point where the cars were braking hard.
|
Dashcam footage of M6 crash in outside lane - No FM2R
