The study of British and Irish roads - their construction, numbering, history, mapping, past and future official roads proposals and general roads musings.
There is a separate forum for Street Furniture (traffic lights, street lights, road signs etc).
Registered users get access to other forums including discussions about other forms of transport, driving, fantasy roads and wishlists, and roads quizzes.
lotrjw wrote:Queue an ordinary motorist slamming into the back of driverless cars that break very suddenly without warning!
Yes drivers should be aware and at a safe distance, but at 70MPH and a vehicle slows suddenly it can catch someone off guard.
In such an instance I would say that it would have to be 50:50 fault seeing as it wouldnt be a good reason for the driverless car to break.
If an ordinary motorist drives into the back of another vehicle that brakes suddenly then the motorist is almost certainly at fault. What you describe is no different to a situation where a car with a human driver brakes sharply or carries out an emergency stop, and the driver of the following vehicle must be alert enough and leave enough of a gap that they can stop without causing an accident.
I didnt say that the person driving into the back wasnt at fault, Im just saying that bad programming of a driverless car in this instance should share a portion of the blame.
If an ordinary motorist hit the break really hard for no reason and someone slammed into the back of them, yes the person who slammed into the first car would be in the wrong, but I would say that, unless the first person had a good reason for breaking so sharply, they should share a portion of the blame.
An emergency stop should be for a good reason, or if someone wants to deliberately do their tires in, on a quiet road with no one else around, like would happen with a learner. Doing one for no reason with traffic behind is dangerous driving.
lotrjw wrote:Queue an ordinary motorist slamming into the back of driverless cars that break very suddenly without warning!
Yes drivers should be aware and at a safe distance, but at 70MPH and a vehicle slows suddenly it can catch someone off guard.
In such an instance I would say that it would have to be 50:50 fault seeing as it wouldnt be a good reason for the driverless car to break.
If an ordinary motorist drives into the back of another vehicle that brakes suddenly then the motorist is almost certainly at fault. What you describe is no different to a situation where a car with a human driver brakes sharply or carries out an emergency stop, and the driver of the following vehicle must be alert enough and leave enough of a gap that they can stop without causing an accident.
I didnt say that the person driving into the back wasnt at fault, Im just saying that bad programming of a driverless car in this instance should share a portion of the blame.
If an ordinary motorist hit the break really hard for no reason and someone slammed into the back of them, yes the person who slammed into the first car would be in the wrong, but I would say that, unless the first person had a good reason for breaking so sharply, they should share a portion of the blame.
An emergency stop should be for a good reason, or if someone wants to deliberately do their tires in, on a quiet road with no one else around, like would happen with a learner. Doing one for no reason with traffic behind is dangerous driving.
The courts sees it more black & white - with just one exception, if a driver hits the back of another vehicle facing the same way then it's 100% the fault of the driver behind - the exception is if the vehicle in front suddenly turns into your path from a side road.
The concept is that if you cannot stop in the distance you can see to be clear you're driving too fast, too close or both - we're all aware that drivers don't leave gaps that long when it's busy, many don't when it's quiet either, and that's why we get nose-to-tail accidents.
lotrjw wrote:I didnt say that the person driving into the back wasnt at fault, Im just saying that bad programming of a driverless car in this instance should share a portion of the blame.
If an ordinary motorist hit the break really hard for no reason and someone slammed into the back of them, yes the person who slammed into the first car would be in the wrong, but I would say that, unless the first person had a good reason for breaking so sharply, they should share a portion of the blame.
It doesn't work like that, for the reasons Ruperts Trooper has explained. If the car in front slows or stops, and you cannot slow down or stop without going into the back of them, you are at fault because you were driving too fast, or too close, or both. Saying they had no good reason to slow or to stop is no defence at all - a court would tell you that you had no good reason to be driving too fast or too close.
In any case I do not believe driverless cars are programmed to simply slam on the brakes at the first sign of a hazard and they certainly don't do it when they "see" a speed limit sign. They are programmed to drive in a way that fits in with the actions and expectations of human drivers, which includes slowing progressively and safely when a reduction in speed is required.
Chris5156 wrote:
If an ordinary motorist drives into the back of another vehicle that brakes suddenly then the motorist is almost certainly at fault. What you describe is no different to a situation where a car with a human driver brakes sharply or carries out an emergency stop, and the driver of the following vehicle must be alert enough and leave enough of a gap that they can stop without causing an accident.
I didnt say that the person driving into the back wasnt at fault, Im just saying that bad programming of a driverless car in this instance should share a portion of the blame.
If an ordinary motorist hit the break really hard for no reason and someone slammed into the back of them, yes the person who slammed into the first car would be in the wrong, but I would say that, unless the first person had a good reason for breaking so sharply, they should share a portion of the blame.
An emergency stop should be for a good reason, or if someone wants to deliberately do their tires in, on a quiet road with no one else around, like would happen with a learner. Doing one for no reason with traffic behind is dangerous driving.
The courts sees it more black & white - with just one exception, if a driver hits the back of another vehicle facing the same way then it's 100% the fault of the driver behind - the exception is if the vehicle in front suddenly turns into your path from a side road.
The concept is that if you cannot stop in the distance you can see to be clear you're driving too fast, too close or both - we're all aware that drivers don't leave gaps that long when it's busy, many don't when it's quiet either, and that's why we get nose-to-tail accidents.
Chris5156 wrote:
lotrjw wrote:I didnt say that the person driving into the back wasnt at fault, Im just saying that bad programming of a driverless car in this instance should share a portion of the blame.
If an ordinary motorist hit the break really hard for no reason and someone slammed into the back of them, yes the person who slammed into the first car would be in the wrong, but I would say that, unless the first person had a good reason for breaking so sharply, they should share a portion of the blame.
It doesn't work like that, for the reasons Ruperts Trooper has explained. If the car in front slows or stops, and you cannot slow down or stop without going into the back of them, you are at fault because you were driving too fast, or too close, or both. Saying they had no good reason to slow or to stop is no defence at all - a court would tell you that you had no good reason to be driving too fast or too close.
In any case I do not believe driverless cars are programmed to simply slam on the brakes at the first sign of a hazard and they certainly don't do it when they "see" a speed limit sign. They are programmed to drive in a way that fits in with the actions and expectations of human drivers, which includes slowing progressively and safely when a reduction in speed is required.
I agree you cant argue with the law and obviously the car behind is in the wrong for the very reasons you both say, I never said they shouldnt be at fault, I guess the law doesnt even account for both being in the wrong in this instance?
On a separate note though stopping dead isnt something thats a good idea without a good reason, but if like you say Chris that driverless cars dont get programmed to do that then no issue.
Yes - if you accept the caveats above - but can you be prosecuted for failing to (allow enough safe space to) stop, if the action wasn't foreseeable?? Like the car ahead braked and stopped very suddenly, without there being any apparent hazards (i.e.no justifiable reason to stop)??
Most of the reasons given have been where there was a foreseeable need to stop, which was ignored.
Berk wrote:Yes - if you accept the caveats above - but can you be prosecuted for failing to (allow enough safe space to) stop, if the action wasn't foreseeable?? Like the car ahead braked and stopped very suddenly, without there being any apparent hazards (i.e.no justifiable reason to stop)??
Most of the reasons given have been where there was a foreseeable need to stop, which was ignored.
What you seem to be asking is whether it's OK to drive close behind someone as long as you think there's no reason for them to stop suddenly. I don't see how that would ever be a defence - unless you have the same view of the road as the driver in front, how can you possibly judge whether they will have to stop suddenly? The reason the vehicle in front might stop is not even always because of something in the road - what if there's a fault with their car, or what if they suddenly have an attack of hayfever and can't see clearly any more?
In short, you're not in control of the vehicle in front, so its actions are never fully forseeable, which is why it is your responsibility to give yourself enough space to react if they reduce speed or stop.
Berk wrote:Yes - if you accept the caveats above - but can you be prosecuted for failing to (allow enough safe space to) stop, if the action wasn't foreseeable?? Like the car ahead braked and stopped very suddenly, without there being any apparent hazards (i.e.no justifiable reason to stop)??
Most of the reasons given have been where there was a foreseeable need to stop, which was ignored.
A potential scenario - line of traffic flowing at steady speed - first vehicle has a mechanical issue which flips it sideways and stops almost instantly - second vehicle is large so obscuring view to following drivers and slams into the wreckage stopping dead - vehicles behind "should" have enough gap to stop safely.
Expect the unexpected and the unforeseen - from time to time they do happen.
Remember you may not be able to see the potential hazard making the lead vehicle stop suddenly.
Chris5156 wrote: The reason the vehicle in front might stop is not even always because of something in the road - what if there's a fault with their car, or what if they suddenly have an attack of hayfever and can't see clearly any more?
I totally agree with this, those would be valid reasons to stop! My point of course was if nothing like that existed and the driver in front slammed on the breaks for no reason whatsoever! I do have to say that I believe this situation is very unlikely from a human driver! I would hope that a driverless car is also never programmed to stop suddenly for anything other than a hazard or vehicle failure.
Apparently although the system has been around for a number of years, drivers are still reluctant to use converted hard shoulders so these aren't attracting the expected traffic. Also, motorists aren't keen on the absence of a hard shoulder, so Chris Grayling, the transport secretary, wants to put in far more emergency lay-bys on smart motorways.
So overall, it looks like there is quite a rethink going on.
Sorry about the paywall thing, but I think other outlets will pick this up as well.
I think some of it is partly because the majority of the nation doesn't know how to drive any motorway with more than 3 lanes, smartified or not. And some of it is partly a hangover from dynamic hard shoulder where people would avoid the hard shoulder for fear of a lane drop at the next junction. The M1 from Derby-Sheffield is four lanes now and works great but even on 25-28 which is D4M it's still easy to spot people sat in lane 2 for no reason.
These articles have come and gone before, I don't expect much to change yet.
Did you know there's more to SABRE than just the Forums?
Add your roads knowledge to the SABRE Wiki today!
Have you browsed SABRE Maps recently? Try getting involved!
Extra road works whilst the additional ERAs are built.
Inevitable clashes with Fixed Taper Position signs leading to the obscuration of the nearside only ones that are being provided, which will mean the deleted offside ones will have to be installed leading to even more roadworks.
Smart Motorways were supposed to be cheaper than widening. This may not quite be the case by the time this work has been carried out?
Patience is not a virtue - it's a concept invented by the dozy beggars who are unable to think quickly enough.
darkcape wrote:I think some of it is partly because the majority of the nation doesn't know how to drive any motorway with more than 3 lanes, smartified or not.
I think this is an important point. Drivers in the UK already have poor lane discipline, and in particular seem to be very reluctant to use lane 1 even under normal circumstances. Any uncertainty in the minds of drivers about how smart motorways are supposed to work and which lanes are in use will surely tend to exacerbate that.
If hard shoulder running is safe - and I'm prepared to believe it is, if the government has the data to back it up - why not simply convert hard shoulders to permanent running lanes, and save the extra cost and disruption of the smartification process?
Someone who actually knows something about this subject from a professional point of view can now come in and tell me I've missed something obvious!
So they are actually thinking about more emergency refuge areas? Well that is a start!
I do agree that in the mind of a lot of people though they see 2 lanes as a all purpose dual carriageway and 3 lanes as a motorway! Its a crazy notion created by the fact that APDCs are normally D2 and motorways are normally D3.
The public needs to be educated in the fact that roads arent defined by their layout. Also people that said about lane discipline that needs sorting too!
The problem is without a nation wide campaign to get people doing more training there is little that can be done, on top of the fact its time and money to get the training. I suppose saying that all new drivers have to do motorway training to use motorways and current drivers have 5 years to get motorway training, except if they have a full bus or lorry licence (not grandfather rights), that would see people understand it all better.
I would be in favour if there was a reward to it like raising the motorway speed limit to 80MPH too!
The fact the lorries usually plough on in Lane 1 means if you use the hard shoulder you end up being stuck at their speed limit, then the hard shoulder is always a lane gain/lane drop, so if you aren't using that junction, it's effort to move into it, and then a few miles later back out of it, at the same time as dealing with the convoy of lorries.
Conekicker wrote:
Smart Motorways were supposed to be cheaper than widening. This may not quite be the case by the time this work has been carried out?
I was just thinking this today as I drove the M1. By the time we are done we could probably have paid for almost as many miles of proper four lane motorway with hard shoulder.
Smart motorway will be the next Grenfell I fear. Done on the cheap and sooner or later a horror crash will happen.
lefthandedspanner wrote:For what it's worth, I've not once seen or heard about the sudden drops in speed limit reported on other smart motorways occurring on the M62- it's always gone 60, 50, sometimes 40 if the traffic is really bad, then back to NSL by intermediate steps, depending on how quickly the jam clears.
Last winter on the M6 on the miles just before the M42 turnoff, I saw on consecutive signs 60 --> 40 --> 20. We also had an ominous oncoming vehicle warning
I see 40 limits all the time on the M25, but I have never seen a limit below that on the Surrey/Bucks stretch I usually drive.
AndrewH wrote:The fact the lorries usually plough on in Lane 1 means if you use the hard shoulder you end up being stuck at their speed limit, then the hard shoulder is always a lane gain/lane drop, so if you aren't using that junction, it's effort to move into it, and then a few miles later back out of it, at the same time as dealing with the convoy of lorries.
The hard shoulder is NOT always a lane gain/drop. Also if the hard shoulder is in operation on DHSR it's accompanied by a 60mph limit, which puts you at the same limit as lorries. Or if you're behind limited to 56mph you're going a total of 4mph slower than the legal maximum anyway.
Did you know there's more to SABRE than just the Forums?
Add your roads knowledge to the SABRE Wiki today!
Have you browsed SABRE Maps recently? Try getting involved!
Anyone else think that speed limits and warnings are left on for far too long?
I'm a regular user of the West Yorkshire stretch of the M62 and the Notts/Derbys/Leics section of the M1 and have lost count of the number of times that I've had to pootle along at 60/50 on a pretty empty road due to there being an "incident" or "pedestrians in the road" etc, then all of a sudden you see the NSL sign and wonder where the alleged incident was.
Would this sort of misleading / incorrect information lead to significant numbers of drivers simply ignoring the warnings?
With respect to the "pedestrians in road" warning, it has to be given on a much longer stretch of road than is actually affected, because it can take a while to figure out exactly where the pedestrian is, so the warning has to be given anywhere they might potentially be.
Other "phantom" speed restrictions are sometimes to give an incident time to clear before traffic reaches it (progressive slowing can create a gap in the traffic, which is necessary for certain sorts of issues to be cleared), but I have a suspicion that many of them are nonetheless just mistakes rather than having a useful purpose.
Pontelad wrote:Would this sort of misleading / incorrect information lead to significant numbers of drivers simply ignoring the warnings?
Yes it does, because motorists will take any excuse to justify ignoring the warnings.
There is a serious problem which doesn't seem to have been anticipated, which is that the public expects the system to be more accurate than is technically possible.
If a broken down car decides to drive off, to have the warnings cleared in 60 seconds would be good work, but then then you'd have many motorists in between complaining of the lane being closed for no reason. Not to mention after the speed limit is lifted, many more will complain that it did say 40 and now it says NSL.
