Self-STOPPING cars are A Good Thing, say motor safety bods Having your car automatically slam on the brakes to avoid a low-speed accident leads to a 38 per cent reduction in real-world rear-end crashes, says a road safety organisation. European road safety research organisation Euro NCAP (New Car Assessment Programme) carried out an analysis of data from various countries. The full …
I hope that the car is programmed to slacken off the emergency braking when that's appropriate and to come to a halt no more than a few feet behind the obstruction. Otherwise I forsee some massive (albeit low-speed) pile-ups on our Motorways, when one of those density waves in busy traffic triggers some vehicle's autonomous emergency braking.
I have something like this, but its not designed to stop the car totally, just reduce the impact speed when a collision is guaranteed...
What IS great is the forward alert, if the car predicts a collision, it will alert me in plenty of time, and I can brake myself, it has saved me from a potential accident when I was in heavy traffic and the guy in front braked while I was checking mirrors/blind spots for a gap to merge into the left lane...
So all in, if done right, I.E. an alert plus emergency braking, then it will reduce accidents...
Friend of mine has a volvo with emergancy stopping action.
It does it on clear roads with no traffic if the sun is "in the wrong place", and emergancy braking with no reason is not a fault or a cause for worry, according to volvo.
They did offer him 60% of the price of his 3 months old car if he wanted to get rid of it..
For a few months I had a near-new Skoda Citigo with emergency brake assist. It also had the direct sequential auto gearbox. Dealer ex-demo at a great price, not features I would have chosen to pay for.
Something wasn't right somewhere though, because from time to time, usually (but not always) involving obstacles which weren't really problems (such as a high hedge on a bend, or a parked car in a place it shouldn't be on a road you're turning right into), it would do an unsolicited change into neutral, fixable only be a reboot (engine off and on again).
I'd known the dealers for years, they did their best, but it seemed basically undiagnosable from their point of view (there didn't seem to be much of a log in the control systems).
Fixed eventually by replacing control unit(s).
Other than that, a lovely little car.
But complexity isn't necessarily a virtue. Just ask Toyota about uncommanded acceleration (and/or read the court case reports in EE Times).
You stopping too close to the car in-front just involves him (through no fault of his own) when someone slams into the back of you and shunts you onto him,
There's really no way to win here, except give yourself adequate distance to stop at all times.
I have this ingrained after several near-misses where I stopped perfectly in time myself and then I look in the rear-view and SEE the guy behind notice too late. Only myself rolling/jumping forward into the distance between me and the guy stopped in front prevented the paperwork from being brought out. And I'm sure if I'd done that, and he'd STILL hit me and shoved me into the car in front, it would be a paperwork nightmare to prove that I'd actually stopped safely and was then trying to prevent an entirely different accident happening.
There's a reason that I bought myself in-car cameras, even on a really old, junky car.
On motorways, especially, you don't want to be within inches of the guy in front no matter what happens. Because that turns a rear-end shunt buffered by your boot and the length of your car into a double-sandwich situation with the engine block coming back towards your legs, and the glass towards your face. Stop, and warn and watch the guy behind, and be prepared for anything. In that situation, you can't even jump into the hard shoulder out of his way because he might have the same idea to stop himself hitting you. Stop early, move forward if you have room and it might stop a fender-bender. Otherwise, you just have to let him hit you and hope you don't pile into the car in front..
"Stop, and warn and watch the guy behind, and be prepared for anything"
In situations like that I bang the hazards on. If you do it whilst looking in the mirror you'll usually see the noses of oncoming cars dip sharply as soon as they start flashing.
> I hope that the car is programmed to slacken off the emergency braking when that's appropriate and to come to a halt no more than a few feet behind the obstruction.
The current Mercedes system does just that - it calculates the space available and applies brakes accordingly. It also causes the brake light to flash in order to alert following vehicles.
Mrs. Bear has a habit, when in a hurry, of taking the car out of gear before it has come to rest, so in reverse this turns the reversing sensors off. BANG! at least twice, and she ain't alone in this habit.
I'd hope that in these auto stop vehicles the sensors work, regardless of the position of the gear leaver.
BTW: This is true for both manual and automatic vehicles as you can slap either into neutral whilst they are moving in either direction.
Me, I wait until the vehicle has stopped before I attempt to power off in the other direction, and my clutch loves me for that.
I can see that when this feature becomes ubiquitous, drivers who used to wait to join moving traffic will just pull out and rely on the auto braking of the cars they are cutting up.
It wouldn't be too difficult for the cars system to upload those kinds of inconsiderate and dangerous actions to the Highways Agency for subsequent prosecution and thus allow the police to get back to looking after the general public, not acting as road monitors.
Hell yeah! Computers only do as they're told and what they are told has to cover every situation or they fail, hopefully safe. My SatNav today attempted to guide me off the dual carriageway today, up the slip road, around the roundabout and back down the other slip road back onto the dual carriageway. The road was busy and very, very slow and the SatNav was "aware" of the traffic conditions from it's little radio traffic thingy. It's set to choose the quickest route and the algorithm "decided" that exit and re-entry was a few seconds quicker than just staying in the queue.
And this is probably the best reason for reducing the speed limit to 20 mph in urban areas, since autonomous braking is really only effective up to about 30 kph, at which point it's a mitigation tool at best.
Volvo's camera system will track, spot, and react faster than us in and it's about time such systems are mandatory fit. Sure, you won't prevent or eliminate all accidents, and no doubt the feel-the-road lobby will complain about increased risks from people not paying attention, but the evidence is now there.
My experience with autonomous braking is that it reacts very late, and leaves the smallest gap possible between it and the object it's avoiding. If someone goes into the back of you... well, that's their fault.
I bought a Volvo after the salesman challenged me to run him over in the dealership car park, a task I attempted with gusto but ultimately failed at.
(I would, if running the country, obviously balance out the 20 mph in built up areas with a new 40 mph limit on the quieter main roads).
My experience with autonomous braking is that it reacts very late, and leaves the smallest gap possible between it and the object it's avoiding. If someone goes into the back of you... well, that's their fault.
Personally (YMMV) I'd prefer something more akin to adaptive cruise control that maintains a speed-dependent minimum distance, and therefore brakes earlier and less aggressively, that a system that jams the anchors on at the last possible millisecond.
Ideally both systems would be present and interact, with the car choosing the most appropriate action depending on the immediate situation.
I do fear too many people will pay even less attention than they do now, just because the car will sort it out. For some (an ever increasing number) that bar is already too damn low.
There are other risks too. Without this being on every car, drivers with the system may get used to its presence and then (for example) drive a hire car without such a system. It's entirely plausible accident rates for those specific circumstances will go up dramatically. People get into habits, especially if they make life easier. One of those habits will be less attentive driving if the car is taking up the slack. Human nature and it's unavoidable.
no doubt the feel-the-road lobby will complain about increased risks from people not paying attention, but the evidence is now there.
One study is a start, but it's not conclusive until backed up by others, contradicted, review, replicated. I would like to see more studies before reaching such a conclusion, including studies examining the possible negative effects of such driver aids.
Feels to me like if one needs a driver aid to be more attentive, one probably shouldn't be driving.
(I'm saying "one" rather than "you" to avoid singling Dave out here).
Personally I'd like it to brake as hard as possible, as late as possible. That way drivers won't become inclined to rely on it to maintain a safe distance, because they won't enjoy having their face imprinted with the maker's logo on the steering wheel every few miles. If this is a last-ditch protection, like ESP, then it's a good thing. If it encourages the driver to disengage brain and stop driving the vehicle properly then it's a bad thing. So no adaptive auto braking for me, thanks.
Yep, After borrowing my bosses car I managed to slam it into the back of a police car in a 50mph zone (the police car had PARKED just beyond the brow of an hill in the middle of the road) Needless to say both vehicles were written off.
Pre ABS I would normally have pumped the brakes to prevent the wheels from locking, but this top of the line car hadn't got ABS and that realisation came too late in the slow motion, life passing moment.
"Was that after the very-public double-Volvo crash tests of exactly this feature where they totalled all the cars involved in front of the world's press?
Brave guy."
Wasn't that Merc cars? And wasn't that down to the fact that the tech wasn't actually ready at the time so they relied on a hidden wooden board on the ground to indicate to the driver to brake but the suspension cushioned the wooden board "ramp" far too well so the driver didn't realise he had to brake and he plowed into the car in front?
Nope. http://metro.co.uk/2010/09/28/volvo-crash-test-fails-in-front-of-journalists-and-spectators-526087/
Re: "reasonable" speed limits - there is no concept of reasonable in someone that can't stick to 30 when the sign says 30.
However, taking your examples, what makes you think it's safer to speed past a school in the dark than in the light? I've been to school-hosted events that last way past 3am, especially for hiring out sports halls for wedding receptions, or even just plain old end-of-term party. And, yes, there's kids in tow. And, no, the speed limit is not always for safety - I wouldn't want some moron doing 60mph past the house late at night and then having to suffer the noise of every morning run too.
You can't justify reasonable to be higher when 30mph suffices to get you where you want to go, doesn't cause a ton of nuisance, and still isn't an accident-free speed and has been like that for decades.
If you want to "go faster", campaign - as was done and ignored a few years ago - for HIGHER speed limits. There are countries with much higher and (pseudo-)unlimited speed limits. Campaign for that, and everyone knows what's happening, what speed to expect of nearby traffic, etc. But that's not what you want to do - you want to go faster than the posted limit and not get caught or then be let-off.
The arguments I see are about robots policing and no real officers and blah, blah, blah. Nobody ever says "Let's just make the 30 limit 40 in this particular area". Why not? Because they know that the statistics will show the accidents rising proportionally.
Think of it another way: "You" might be able to "control your vehicle" at those speeds (I may disagree, but whatever). But what about the pillocks. Because it says 50mph, they'll do 55 anyway. Because it says "reasonable", they'll spend thousands of pounds of tax money going to court to argue that 70mph on a blind corner while they are racing their mate was "reasonable". It doesn't work.
Pick a number, stick to it. If the number's not enough, ask to have the number raised. NOBODY ever does. If you're just going to ignore the number whatever it is, please hope you don't hit my car (or myself or friends) even gently.
Don't say "I just want to be able to flout the rules". Tell people the speed you want on that particular road. If more people agree than disagree, surely it stands a good chance of happening and improving traffic flow? And with modern traffic systems, there's no reason a school road can't be 20 in the day and 40 at night or similar - we have the technology.
But you'll find a) Nobody asks. b) You don't care enough to ask, c) if it's raised to 40 you'll want to do 50 "just because", d) accidents will get more frequent and more serious, e) coppers and the locals won't take kindly to you zooming through their neighbourhoods at 3am at any speed anyway.
WRT reasonable speed limits:
a pedestrian hit at 20mph has a 98% chance of survival (as long as they don't hit head on a curb)
a pedestrian hit at 30mph has a 90% chance of survival
a pedestrian hit at 35mph has a 50% chance of survival
a pedestrian hit at 40mph has a 10% chance of survival
What's a reasonable speed limit for several tons of steel in a residential setting and why should residents of an area be forced to kowtow to those passing through?
"I bought a Volvo after the salesman challenged me to run him over in the dealership car park, a task I attempted with gusto but ultimately failed at."
Wait - are you saying all those bonnet-mounted targeting aids on Mercedes cars are about to become useless...?!?
We need a mechanism or at least a legal wording that allows for appropriate speed limits, rather than fixed ones. 20mph may well be an appropriate limit approaching a well-lighted school at 8.50am on a wednesday morning in term time. It is not appropriate at the same place at 3am on a Sunday morning, when it is dry and there is no traffic. Similarly 70 or even 80mph may well be appropriate on a straight, rural main road, with no traffic, on a clear, dry, warm day. 30mph may be appropriate in the same place during snow, poor visibility at dusk and with traffic. In both cases the present silly system says 60mph is okay.
We should do away with fixed limits, and instead have guidelines - and variable penalties for unreasonably or dangerously going outside those guidelines. Of course, that would require human beings to enforce things, rather than robot cameras, and would make it much harder to generate vast sums from inappropriate speeding fines.
"We should do away with fixed limits, and instead have guidelines - and variable penalties for unreasonably or dangerously going outside those guidelines"
There used to be in the UK - it was called police discretion. However there are no longer any police around just private "Go Safe" firms with laser speed gun and fixed Gatsos with no discretion.
The person who hits a child who runs out in front of them while they were travelling at 30mph but didn't react because he was on 9 points and staring avidly at his speedo might avoid prosecution as the child was "at fault", however the driver who was doing 34 and avoided the child because he was paying full attention to the road and surroundings but got nabbed by the speed van a few minutes ago will get prosecuted.
"There used to be in the UK - it was called police discretion."
Long before that, there was a period where there were no speed limits at all in the UK, after the blanket 20mph limit was abolished in the 1920s
It was rapidly increasing rates of crashes and deaths which resulted in a 30mph urban speed limit (a number pretty much plucked out of the air) being quickly reimposed.
We should do away with fixed limits, and instead have guidelines
That's effectively what we have now, the only fixed limits are where there are speed cameras. Everywhere else people will quite happily use the posted limit as a guideline, with five to ten miles per hour treated as acceptable "leeway" above the limit.
There are three problems with the "letting the driver decide their own safe speed" argument:
1) Although I think I am a safe driver, other drivers are clearly not safe, and are often not even paying attention to where they're going.
2) No-one can yet read the future, so we never know when we might be about to crash into something. Crashes are almost always completely unexpected by the driver, who thought that they perfectly were safe up until that unexpected thing happened.
3) Other people can no longer make useful assumptions about how fast any approaching car is travelling. In a 30mph limit you can be pretty sure that nothing will be coming at more than 40mph, if you're trying to pull out of a side road, or trying to cross the road on foot. With discretionary speeds, you might find an "expert driver" paying strong attention and doing a "safe" 50mph suddenly appears. So it's much more difficult to pull out of side roads, and more difficult for people to cross roads on foot.
Speed limits are most needed on roads which appear to be safe to drive at faster speeds, but are in fact quite risky at faster speeds. Speed limits are least needed where the risks are obvious, such as outside a school at school run time, or in a supermarket carpark during shopping hours.
I was involved in a crash where another driver pulled out of a side road straight into the nearside corner of my car. No way I could have avoided that, but because there was a 30mph limit (due to lots of junctions and people being around) no-one was seriously hurt. Even at 30mph it was a nasty crash, though, and I wouldn't want to try it again.
Speed limits also help to improve traffic throughput, by reducing the feedback-loop lag all human drivers introduce. For motorways, maximum capacity is reached with a top speed of around 40mph, hence the variable limits on the M25 go down to that speed.
In towns, slower speeds mean easier transition between more main roads and side roads, where turning into a side road always needs to be done quite slowly, and turning out is often done from a standing start. More haste, less speed, works well for motor traffic. Average trip speeds can actually go up with a lower overall maximum speed, where you have to negotiate lots of junctions.
20mph limits on residential streets, and in major towns, are very sensible. Which is why they're common in Europe (30kmh) and increasingly common in the UK too.
"Speed limits are most needed on roads which appear to be safe to drive at faster speeds, but are in fact quite risky at faster speeds. "
Adjusting the roadside furniture is actually far more effective at regulating speed than signs.
In particular in the UK:
Pedestrian fences speed up average traffic by 5-10mph
Yellow lines speed up cars by 2-4mph
Pelican crossings speed up average traffic by 10mph (The green light.....)
painting cycle lanes or flush medians speeds up traffic by 5mph.
ANY kind of segregation of road and pedestrians results in drivers being less prepared for pedestrians stepping off the curb.
One example: Pedestrian injury rates are 25% higher around crossings because pedestrians will start crossing before they reach the stripes, which many drivers simply don't expect.
You get the idea.
Drivers slow down if there are perceived hazards - and fencing hazards off in an area where there have already been problems paradoxically reduces safety because the traffic speed increase and reduction of driver attention outweigh any reduction in pedesrian incursion (slightly fewer crashes but significantly greater injuries)
"20mph may well be an appropriate limit approaching a well-lighted school at 8.50am on a wednesday morning in term time. It is not appropriate at the same place at 3am on a Sunday morning, when it is dry and there is no traffic."
If that school is in a residential area (most are) then the residents tend to get pissed off with arseholes whizzing by at 50mph at 3am - road noise is a significant factor in modern speed limits and there are enough foxes/deer/cats or whatever else around that it's still not overly safe to increase speed by more than a few mph.
We should do away with fixed limits
In an ideal world, I agree with you. We should not need speed limits, because people should be taught how to judge a safe speed for themselves and road signs should be clear and be placed only where needed. Also, as you said, we would need more cops on the road to judge whether someone was driving too fast.
If a motorway is completely empty, there is very little extra risk driving at 90+ rather than 70. A driver should then be able judge that he can drive that fast, but then slow down when he sees another vehicle. He should be able to judge that this particular road is fine to drive at 40-50 on at night, but during the day it would be appropriate to stick to 25-30.
Unfortunately we do not live in an ideal world. Many people do not know how to judge a safe speed to drive at. They drive too fast, leave too little space between them and the car in front of them, and all manner of unsafe things. Speed limits are already just a limit. If I find a road where driving at the 40 limit is unsafe (due to traffic, weather, road conditions, the big line of school children walking along the path balancing on the kerb like a tight-rope) I will slow down. Many do not.
Relying on your own judgement is fine, but relying on the judgement of all drivers, many of whom don't even know what the national speed limit is or how to maintain a steady speed on a straight, clear road, is a folly. The only way to make it workable would be to raise the standard of driving skills of everyone, which I do not see happening...
> camera system will track, spot, and react faster than us in and it's about time
> such systems are mandatory fit
Which is all very well but fails to take into account that the vast majority of cars round you won't have that feature. So you might save yourself from hitting the car in front but your (probably) unexpected braking might mean the person behind you in their older-spec car just goes into the back of you..
(Firm believer in the 2-second rule. Which makes me very much a minority on the roads, especially as you get closer to main conurbations)
" autonomous braking is really only effective up to about 30 kph, at which point it's a mitigation tool at best."
My Adaptive cruise control works pretty well in autobraking from speeds of 20mph and up.
There's no reason why autobraking can't run at high speeds. It just requires the car looking further ahead.
This is the sort of thing vehicles should strive for. Humans are vastly more capable of solving real world problems than a computer, but a computer has the reaction and response times to halt a vehicle safely to avoid a collision. Therefore, the ideal would be to let the human drive the car, but add sensors to ensure the vehicle can be brought safely to a halt.
A danger of this of course is that if the car saves the driver's bacon they might be inclined to drive more recklessly in the first place (the whole airbag / seatbelt thing all over). So it probably needs to come with other measures to ensure the vehicle is being driven in a safe manner to prevent that - automatic distance keeping, lane tracking etc.
"So it probably needs to come with other measures to ensure the vehicle is being driven in a safe manner"
Isn't that the job of the police? Unfortunately in the UK there now seems to be fewer and fewer traffic police on the roads whose job it was to both deter and to catch drivers driving in an unsafe / dangerous manner. instead they have been substituted for 'road safety officers' with no powers of arrest, fixed speed cameras or mobile camera vans who's only role is to catch those going over the speed limit.
I've installed a dash-cam in my car and not a day goes by without filming idiots on the road with no situational awareness, undertaking, changing lanes with no indication, or hell bent on pushing you out of the way on the road because their journey is obviously more important than anyone else's.
Rant over, time for that pint.
"Isn't that the job of the police?"
Police are few and far between and I didn't say illegally. I said recklessly. The driver might take more risks and not even be conscious of it. They might tailgate more, they might speed more, they might engage in actions that their car will bail them out of in an emergency.
But if the car has the ability to react in an emergency it could also do other things - measure road conditions, traffic conditions, measure the gap between the car and those in front and behind, the lane markings, the speed limit and other things that impact on safety. It doesn't necessarily have to do anything more than give out an annoying bong if the driver is doing something unsafe and the chances are the driver would adapt their driving.
I guess the UK hasn't figured out what local police can do as they have in the US. Over here, they're revenue generators. Write out traffic tickets and the city/county/whatever makes money. The towns the utilize this philosophy usually have a round the clock police presence on the roads.
@Mark 85
In the UK the money from speeding fines now goes directly to the government treasury, which then distributes most of the £150m+ each year to the local council authorities, rather than directly back to the police. Which is why there are less traffic police on our roads now as it doesn't pay them anything and councils pay for mobile camera vans to catch us instead.
During the transitional period where some cars have this and other don't I would expect an increase in rear-end shunts...the car in front of me has a sensor which can detect an obstruction, think faster than a human and apply the brakes. I'm following at the Highway Code distance which assumes both drivers have similar thinking time/distance, and I could fail to stop quickly enough.
If you are following the highway code distance then you will be able to stop in time regardless of how quickly the car in front breaks. The highway code distance is assuming something has fallen off the back of a lorry and so isn't moving, the stopping distance should be the distance required to recognise, break and come to a stop before hitting it. Most drivers don't follow the highway code however and assume that a shorter gap is sufficient, relying on the fact the car in front is unlikely to come to a sudden halt and so the total distance you have to stop over is longer than the initial gap..
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