Safe Speed Forums

Submarines travel slower than cars and chage direction much less abruptly, therefor the systems in them would be far less prone to error.

Mind you, perhaps we could get our resident 'non-legal expert' submariner to help us with this one, if he's listening??

What will cause speed limiting systems to fail in the short to medium term will be the set up costs. The morons in charge of the current pilot scheme thought they could see a cheap way of implementing it using GPS (ie. using infrastructure put in for an entirely different purpose at someone else's expense)

A bit like those high speed trains the UK tried to introduce on the cheap by attempting to design them to run on existing (then 100 year old) rail tracks. Every other nation realilsed an investment in the rail lines themselves to update them was required - we tried to do it on the cheap by making the trains tilt. 25 years later and we are still only just getting round to upgrading the tracks.

Would the cost of a working speed limiting system really justify the huge investment - especially as it will kill the revenue stream from speeding fines and probably won't actually reduce the cost to the economy from RTAs by very much, if at all?? The study produced no evidence whatsoever that it can reduce accidents and fatalities - their report merely makes assumption on the basis of other flawed research.

Don't forget speed cameras - road safety on the cheap. Okay, it isn't actually working but it's bloody cheap as far as the public purse is concerned. Much cheaper than educating drivers properly, and improving layouts at accident black spots, and training police, and paying their wages, and buying them cars and kit to do a proper job of policing the roads. This way even makes a bit of pocket change for Gordon. Never mind the quality, feel the width!

I think this is the new British disease - why spend what's necessary to do the job properly when you can do a cheap half arsed job, spend years scratching your head wondering why it isn't working properly, and then waste about the same amount of money as it should have cost in the first place either trying to prop up or fix the Heath Robinson effort that you settled for.

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Make everything as simple as possible, but not simpler - Einstein

The van I drive 250 miles a day has a top speed limiter fitted , limited to 68mph, fine I cant speed on the moterway which leads to foot on floor and watching the scenery, and giving just enough eye to road to stay undamaged, it really does get boring, unless theres lots of traffic on which to concentrate.
or

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Brian of Plymouth
When will the government realise , that to err is only human, to be perfect is to be GOD.

Wouldn't the same argument say that you should keep talivans and gatsos, as they increase the concentration demanded? Or perhaps make windscreens really hard to see through? Surely anything which makes driving simpler by removing the need to concentrate on something that is otherwise unnecessary is helpful rather than harmful? So, at present, we need to concentrate on looking out for speed limit signs, and checking our speedo. Neither of these activities are useful in themselves, just as looking out for talivans and gatsos isn't. So to me, speed limiters would be as helpful as getting rid of talivans and gatsos in that you would no longer need to concentrate on non-useful aspects of driving.

Of course, you could argue that another way to remove all the distractions is to get rid of speed limits so you neither need to look out for speed limit signs, nor look out for enforcement, and I would accept this argument.

No. They sap concentration away from what really matters. There is a finite amount of time and effort that can be expended when driving (regardless of what you say about how much effort you put in) and anything that consumes some of that time and effort unless it is directed towards the road and hazards ahead is itself a danger



By jove, I think he's got it.

We do, however still need some sort of advisory limits for the hard of thinking. This was originally the purpose of limits, but someone saw their excessive enforcement by automated means as an effective revenue raiser.

The problem with limiters is they only make sense if you believe that the speed limit always and without exception equals the safe speed of the road and conditions. This is of course ludicrous.

The whole purpose of SafeSpeed is to point out the error of this belief.

What he said.

Er.... no.

Absolutely, but the flip side is also true, that removing or eroding concentration levels on necessary things is harmful rather than helpful.

So don't do it then Actually I think it's unreasonable, but as I keep saying it's lower on my list of priorities. Better to drive safely and run the risk of points than make absolutely sure you'll never get points and run the risk of driving badly.

Not if they have negative side effects that prove to be even worse than those of the gatsos and talivans. We won't know without trying it, but I believe they will make things worse for the reasons I've already given.

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Make everything as simple as possible, but not simpler - Einstein

I see that as a problem with absolute speed limits, though, not speed limiters. And it isn't unsafe to travel slower than would be safe (provided everyone does it, this is the error in how people interpret the Solomon curve), merely inconvenient.

I'm not old enough to remember it, but there were days before speed limits, weren't there? Didn't they drive the e type jag at very high speed along the M1, which was legal at the time? I'm guessing that there must have been perceived problems with people's driving in the absence of limits that caused limits to be introduced.

Depends on whether speed limits are set appropriately. For example, on a motorway limiting people to 70 mph would mean there's simply not enough stimulation and it would be easy for people to fall asleep.

On the other hand, if the limiter was set to 100 mph then people wouldn't just sit on the limiter, they'd have to concentrate on their driving -- and could probably do so better since they weren't having to worry about their speed.

Stevei - "Inertial guidance" can be very accurate. A friend of mine was an airline pilot and on a flight from Gatwick to JFK, the inertial guidance was only about 30 feet out after 3000+ miles. So I guess you could reset the system as you passed through, or reach a known destination, ie home or work. It could work, i expect their are many other issues with such a system

Yes, but that is for vehicles that generally travel in very long, straight lines and require a space the size of a small city to change direction.

IMHO something the size of a speed bump could interfere with inertial guidance in a car...

Inertial guidance is also used in fighter/bomber aircraft such as the Tornado and in cruise missiles. The direction changes are much more violent than the submarine example - think of the worst turbulence that you have experienced on a flight, and magnify as the larger aircraft are not affected so much as the little ones are.

The tricky part used to be very expensive gyroscopes that are essential to sensing direction changes, but these are now appearing in consumer goods. I am thinking of the laser gyro developed by British Aerospace (sorry BAE SYSTEMS as it is now) for missile and aircraft guidance, which are the vital component in keeping a Sedgeway upright. Still expensive by anybodies standard and a very long way away from the < £100 for the whole kit that will be required for automotive use. After all if the car is sold for £7K, then how much is the total component cost - £3K or so?

Which takes me back to the cost/benefit point. I still don't believe a system that is both cost effective and fully functional will ever be produced in my lifetime (especially considering the real benefits are miniscule anyway).

stevei,

I've only just come across this thread and others have already made many of the points I would have made in response but I have a few additional comments.

Some of what you write has a superficial, narrow logic; some of it is perfectly sensible; but much of it is hopelessly simplistic.

For example:

It is, statistically, "staggeringly unlikely" that any reasonably competent and careful driver will crash. If, as I may be willing to accept, your safe driving ability is in the top (say) 2% of 'safe drivers' your chances of crashing are even more staggeringly low than the majority of 'safe drivers'. So what. That advances the debate by not a millimetre.

You say:

Do you really think you are the perfect driver and that you never make a mistake? I think it would be relatively easy to engineer circumstances that would have you driving into the back of the car ahead, no matter how careful you think you are.



Cheap shot. As Paul has already said, driving is a continuous process of crash avoidance. It is easy enough to avoid crashing if that is the only objective. In fact all drivers, even you, have another objective - to get where they want to go more or less in the time thay have allocated for the journey. That's where the balance between safety and progress comes in.

Did you actually read all of the thread before posting this?

Well, as I implied, I struggled to make any sense of a lot of it.

You think lots of people want to drive 50% faster than you. How do you know that - are you psychic?

You think it is "extraordinarily dangerous" to drive at the speed limit because everyone else wants to drive so much faster. So you drive everywhere at the speed limit and find that everyone else wants to drive 50% faster than you?

And all these drivers tailgate you and that makes you take "evasive action" to avoid them. You seem to have a really serious problem with tailgaters. I wonder why they pick on you? Oh and do read the section on tailgating on the main site. Speeding up, if it makes you uncomfortable, is definitely NOT the answer.

So you're 100% in favour of speed limiters because that will mean that a driver looking to overtake can't exceed the speed limit and that will stop tailgating. How will that reduce the incidence of tailgating. Have you not observed what almost every other driver knows, that tailgating is more common where traffic speeds are restricted to a narrower range, whether because of congestion or threat of enforcement. Why would speed limiters act differently?

You believe that if everyone had speed limiters, tailgating would be eliminated because the 'would be' tailgater would not be able to 'catch up' with his victim. Really? So the introduction of speed limiters will miraculously create safely spaced streams of traffic able to progress smoothly at the same constant speed unhindered by all incidental hazards (such as: changes in speed limits, junctions, traffic lights, roundabouts, traffic jams, trucks, buses, bicycles, turning vehicles, pedestrians, to name a few)?

I'm absolutely sure that will never, ever happen.

Okay, just that your points seemed to have already been answered, as well as the general point I made about my comments being designed to be read as a whole, i.e. when I write something I assume that people will read it in the context of what I have said previously in the same thread, I don't restate things in posts in the same thread.


I know it because that is the speed that free-flowing traffic moves on those roads, and it's quite easy to see how rapidly someone was driving to catch you up in the first place.


I don't understand how this point differs from the previous one.


I assure you that speeding up most definitely solves the problem. I don't know why you put "evasive action" in quotes. If someone tailgates me and tries to dive past, putting their vehicle on a collision course with mine, forcing me to brake to let them drive into the road space that I would otherwise be occupying, that seems a reasonable definition of evasive action to me.


Most importantly, the driver wouldn't be able to catch me up in the first place, because they can only do so by exceeding the speed limit. Why do people have such difficulty grasping this?


That's right, I think you've got it.


There are no such hazards on these roads, that's why people drive at 50% above the speed limit. I have said before that I would be equally happy to have the speed limit increased to a sensible value, however I have never received any support in this desire. If I can't be allowed to speed up, the only other option that I can see is to make everyone else slow down, it's clear to me that it's very dangerous to have some vehicles feeling forced to drive at one speed while other drivers want to drive at a much greater speed, trying to overtake in places where it really isn't appropriate.

If someone accelerates slowly up to a limited speed, they can be easily caught up by someone accelerating more positively. Especially if the road has plenty of bends.

So you can still caught up and tailgated even if both cars are limited to the same speed.

The limited speed sould still be 10/20/30+ mph over the safe speed for the road, so a safe driver could still be caught up by someone who doesn't take into account the road conditions.

Limiters do nothing for road safety. A bad driver will still be a bad driver.

Only if nobody ever slows down below the limited speed, nobody ever turns into a road in front of someone else, nobody ever accelerates up to the limited speed slower than the person behind, nobody ever....etc etc
And then all vehicles must have the same limit - there's nothing to stop a 60mph car from tailgating someone stuck behind a 40mph lorry.
I don't believe that people will not tailgate if they can't go any faster - in fact, I believe it'll make it worse, because people will be unwilling to lose even the tiniest scrap of speed when they think they're already going too slow.



Yes, we all want speed limits set to a sensible level - but we're never going to get that, are we?
If speed limits are to be inviolate then they must (to be justified) be set to a level which few people would exceed in ideal conditions. And if this were the case then what would be the value of speed limiters?



What speed would that be? We would then have to slow all cars to 40mph so they don't have to overtake HGVs. But you still get tractors - so we'll have to limit speeds to 30mph. But what about bicycles? 10mph limits anyone?

Cheers
Peter

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Only when ideology, prejudice and dogma are set aside does the truth emerge - Kepler

The "if" is crucial here. Yes, a slow driver who is frustrating a faster driver behind them could still get tailgated. But at the moment we have the perverse situation where a faster driver (i.e. a driver who is capable of driving safely at higher speed) might actually drive slower than a slower driver, if the faster driver feels obliged to drive at the speed limit whereas the slower driver ignores the speed limit. In this scenario, if the faster driver is ahead, they will accelerate swiftly to the limited speed, opening up a gap over the slower driver behind who will then be unable to catch them.

But even when you have several cars together, all going along at the limited speed, I don't understand why they would tailgate. They can't go any faster than they're already going, so what would be the point of driving along close to the car in front, I would have thought the natural reaction would be leave a safe gap, relax, and just drive along in a calm and safe manner.


Given that most speed limits are currently way below the safe speed for the road, are you advocating doubling all speed limits, say? This is what I think it would take to get limited speeds to 10-30mph over the safe speed for the road. Speed limits, at the moment, seem to represent a speed that the worst possible driver can drive at in all conditions bar perhaps absolute freak weather conditions. Limiters would force policy makers to drive at (or be driven at) the speed limit, so if a particular road's limit is frustratingly slow they will soon get fed up. Remember that they don't suffer much if their driver gets points for speeding, the current system does little to cause inconvenience for people who are driven around by someone else, whereas mandatory speed limiters would.


True, but it will make them drive more slowly. Universal mandatory speed limiters would then show whether this makes them safer or not.

This is where the roads you drive along start to affect your views a lot. I have virtually zero problems in my driving with the 40mph HGV limit. The sections I drive along that are single carriageway NSL are relatively brief, and very congested, such that even the 40mph limit is not typically capable of being achieved. On the roads I drive on, bicycles don't cause much of a problem, and tractors are rare. And in any case, none of the problems you describe are problems with limiters, they are problems we already have without limiters. The limiters simply stop people from doing something that they shouldn't be doing anyway.