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 Post subject: Conspiracy
PostPosted: Sun Mar 07, 2004 18:48 
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This topic is for comments on the Safe Speed page:

http://www.safespeed.org.uk/conspiracy.html

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PostPosted: Wed Nov 17, 2004 20:50 
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I have some responses to this article:

It lists assumptions, and the discusses why those assumptions are false. The first one is

Quote:
... that road accidents are rooted in physics


Well, in all honesty, collisions are a subset of the field of physics.

Quote:
This is the "faster you go, the harder you'll crash" school of thinking. Like many oversimplified beliefs it contains a grain of truth to add plausibility. But the physics has no effect until the safety systems have failed and an accident is inevitable


So, if you are going at 100mph any crash you are involved in, won't be harder than if you are travelling at 30mph? And quite right, the physics of collisions aren't in play until a collision occurs.

Quote:
...During those 7 years our average driver may well have been exceeding the speed limit for much of the time. But on the day in question, something goes wrong - he makes a mistake or is unable to avoid the mistake made by another. With a little consideration, it should be obvious that the physics are the same every day.


True, but because you may have been speeding every day and haven't crashed yet doesn't mean that higher speed journeying doesn't carry an increased risk. Noody says that speeding guarantees an accident. If you were unskilled/unlucky enough to have an accident every day you drove, and you sped evertime you drove, you'll find your accidents are probably going to be more serious on the whole. That's the physics thing.

Now, a response for this has already been crafted:

Quote:
Oh really? The average impact speed is a small fraction of the free travelling speed - we have driver response to thank for that. At the imagined lower speed there's no guarantee (and little likelihood) that driver response will be as effective.


To which I agree. However, despite the fact that people generally slow down before an accident occurs, that doesn't mean the impact speed is the same. The impact speeds are probably faster. Added to that is accidents centred around loss of control, which are more likely to occur at higher speeds and during which the driver isn't able to reduce his speed so easily (he is not in control).

Quote:
Speed in miles per hour is little help in deciding the safety or the danger of a situation. Instead we must look at speed relative to the circumstances.


Agreed. Also note, that the speed limits vary depending on general road conditions.

Quote:
Drivers can't be trusted to set safe and appropriate speeds.


Yes, they can, and they are. Which is why it says, in the highway code:

The speed limit is the absolute maximum and does not mean it is safe to drive at that speed irrespective of conditions. Driving at speeds too fast for the road and traffic conditions can be dangerous. You should always reduce your speed when

* the road layout or condition presents hazards, such as bends
* sharing the road with pedestrians and cyclists, particularly children, and motorcyclists
* weather conditions make it safer to do so
* driving at night as it is harder to see other road users.



I agree with many of the points raised here, but basically saying that speed isn't an important factor in accidents is crazy talk. In a collision kinetic energy is equal to the product of the mass of the object and the square of its velocity squared


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PostPosted: Thu Nov 18, 2004 01:20 
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Quote:
I agree with many of the points raised here, but basically saying that speed isn't an important factor in accidents is crazy talk. In a collision kinetic energy is equal to the product of the mass of the object and the square of its velocity squared


First and trivial, you've squared velocity twice. Once is enough.

Second, if you are serious about kinetic energy then you have to worry about mass. A heavy truck travelling at 50 mph may have the same kinetic energy as a light car travelling at 400 mph. Where is the reality check?

Third, speed is a factor in every accident. But it is also the sine qua non of transport. The question is what causes accidents and how can they best be prevented or mitigated. The answers to that question can only come from continuous study, experimentation and objective evaluation. People who assume they know the answer and refuse to look objectively at the factual evidence are a major hindrance to the solution. From my study of the situation, the "speed kills" industry is just such a hindrance.

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PostPosted: Thu Nov 18, 2004 01:22 
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Mod wrote:
Well, in all honesty, collisions are a subset of the field of physics.
The effects are, but usually not the causes. With the exception of mechanical failure, drivers cause collisions. Even then, if a mechanical failure came about by neglected maintenance any collision is arguably still caused by the driver/owner.

Mod wrote:
So, if you are going at 100mph any crash you are involved in, won't be harder than if you are travelling at 30mph? And quite right, the physics of collisions aren't in play until a collision occurs.
You got it. Cause and effect. :)

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PostPosted: Thu Nov 18, 2004 01:49 
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Mod wrote:
I have some responses to this article:


Hi Mod,

Welcome, and thanks for your contribution. I can see where you're coming from, but I think you're assuming too much. Can I please recommend that you study the following:

http://www.safespeed.org.uk/againstcameras.html ?

You'll find explanations and detailed references that answer most (if not all) of your queries. If there are remaining questions after that, I'll be pleased to answer in any amount of detail.

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PostPosted: Thu Nov 18, 2004 03:33 
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Quote:
First and trivial, you've squared velocity twice. Once is enough.


You must square it twice muhahaha!! No you are quite right, I went a bit power mad there (pun intended), I also forgot to half the mass. I blame that on the Chinese takeaway that arrived at my door at that moment.

Quote:
Second, if you are serious about kinetic energy then you have to worry about mass. A heavy truck travelling at 50 mph may have the same kinetic energy as a light car travelling at 400 mph. Where is the reality check?


I dunno, lets do the maths.
k.e of a 17t truck travelling at 50mph. I make that to be 22m/s
so that's 8500 x 22 x22 = 4,114,000 Joules. So about 4.1MJ

In order for a 1t car to be have that much kinetic energy
velocity squared = 4,114,000 / 500 = 8228
velocity = 91m/s
which is about 200mph.

So there you go, but we already knew that if you get by a HGV you are in serious trouble...that still doesn't change the fact that if the truck was going 20mph faster, it would have twice the energy and thus twice the potential for damage.



And Paul, thanks for the response. I read the article you linked to me, and largely agree with what it has to say...with some fundamental issues. The main one is how is all this data collected. I work in car insurance, and I well know that we can almost never prove the speed a third party was travelling, and the claims that they were clearly speeding are many. Obviously some people stretch the truth, or are just wrong...but simply because 60 of those collisions could be proven to have occurred over speed limit does not mean it was only 60.

At the end of the day, speed is an important factor in an accident. We could scrap speed limits. However, if someone was going 50 next to a school at 15:30, would we have to convict them of dangerous driving? Since we couldn't do them for speeding. And if we base a dangerous driving conviction based around the fact a driver was going too fast for the road conditions we would have to develop guidelines for appropriate speeds for certain conditions: this would end up happening by case law anyway. So we would end up with speed limits, probably hundreds of them, and nobody would no what the speed limit was.

So we set a limit. This is not a reccomended speed to drive at, but a limit. As stated in the highway code. The limit depends on the general road layout/conditions etc. so a duel carriageway near a school tends to be a 40mph zone. You may think its safe to go 50mph on this road, and if so, you could lobby to have the limit changed.


But anyway, my point was that saying that the speed you are travelling is almost irrelevant (as indicated by the following quote),

Quote:
Oh really? The average impact speed is a small fraction of the free travelling speed


is crazy talk.


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PostPosted: Thu Nov 18, 2004 04:10 
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Mod wrote:
And Paul, thanks for the response. I read the article you linked to me, and largely agree with what it has to say...with some fundamental issues. The main one is how is all this data collected. I work in car insurance, and I well know that we can almost never prove the speed a third party was travelling, and the claims that they were clearly speeding are many. Obviously some people stretch the truth, or are just wrong...but simply because 60 of those collisions could be proven to have occurred over speed limit does not mean it was only 60.


We collect data as well as we can, of course and then try to fit it into a framework of knowledge. The data happens to fit the knowledge framework very well, and therefore they mutually reinforce one another.

We don't have to rely on contributory factor data to know that "speeding" at impact isn't a common factor in crashes - we can look at crash severity data instead. There were five completely independent references in the previous reference:
http://www.safespeed.org.uk/againstcameras.html
Section: "3) The Truth About Speed and Accidents"

Mod wrote:
At the end of the day, speed is an important factor in an accident. We could scrap speed limits. However, if someone was going 50 next to a school at 15:30, would we have to convict them of dangerous driving? Since we couldn't do them for speeding. And if we base a dangerous driving conviction based around the fact a driver was going too fast for the road conditions we would have to develop guidelines for appropriate speeds for certain conditions: this would end up happening by case law anyway. So we would end up with speed limits, probably hundreds of them, and nobody would no what the speed limit was.


Road safety already utterly depends on drivers setting appropriate speeds. Yet most of our drivers speed frequently. "Speeding (exceeding the speed limit) isn't the problem.

Mod wrote:
So we set a limit. This is not a reccomended speed to drive at, but a limit. As stated in the highway code. The limit depends on the general road layout/conditions etc. so a duel carriageway near a school tends to be a 40mph zone. You may think its safe to go 50mph on this road, and if so, you could lobby to have the limit changed.


We don't campaign against speed limits. What we do campaign against is overemphasis on speed limits, and pointless enforcement of purely technical violations. What we need to detect and prosecute are safety violations - something very different.

Mod wrote:
But anyway, my point was that saying that the speed you are travelling is almost irrelevant (as indicated by the following quote),

Quote:
Oh really? The average impact speed is a small fraction of the free travelling speed

is crazy talk.


Oh no it isn't. We don't anywhere near enough high severity accidents to support the alternative. You find a good example proof in the section "deadly speed" on page:
http://www.safespeed.org.uk/why.html

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PostPosted: Thu Nov 18, 2004 04:44 
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Paul,

the link on your last post has a typo in it. That's about all I can say as I agree with everything in it.

Just above "Are drivers perfect?" you say 'drivers are changed' when I think you mean 'drivers are charged'.

Great job, great work, keep up the fight!

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PostPosted: Thu Nov 18, 2004 04:56 
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M3RBMW wrote:
the link on your last post has a typo in it. That's about all I can say as I agree with everything in it.

Just above "Are drivers perfect?" you say 'drivers are changed' when I think you mean 'drivers are charged'.

Great job, great work, keep up the fight!


Thanks Ross. I've fixed it.

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PostPosted: Thu Nov 18, 2004 10:01 
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I know that speeding isn't a common factor in crashes. Most crashes happen at about 5mph where someone shunts into someone at a roundabout or junction, or reverses into somebody else. I would be lying if I asserted that most accidents happen whilst someone is speeding. However, it is almost impossible to know what speed most accidents happen at. Most accidents aren't even reported to the police (or the police refuse to get involved with them). The frequency with which people tell me they were travelling at 27mph before the accident assures me that a good deal of those people were speeding, combined with the large number of people which assure me that the other person was going far too fast.

Unfortunately, we cannot go back in time, transport ourselves to the scene of the accident, turn invisible and do a speed check...so we have to rely on what people tell us.

So in short, whilst we can sometimes know when a person is speeding, we cannot know every time an accident happens, so attempting to compile statistics on it is very difficult. If we assume that most people speed most of the time (when conditions are good), then we can also assume that most accidents that happen where one party is travelling at or around the speed limit actually occured over the speed limit, no?



Quote:
Road safety already utterly depends on drivers setting appropriate speeds.


Agreed, something emphasized in the highway code, as I have said. The government has set a maximum possible speed on all roads that conform to certain types with certain situations (schools, elderly people's homes etc). The driver then has to decide what is a safe speed within that speed.

If we basically say "sometimes it's ok to go 40 on a residential main road", we then have to define when those sometimes are, so that we can prosecute when someone breaks the rules. In essence, you would create more speed limits, which are confusing and strange. Either that, or we would have to make sure everyone passes an advanced driving course so that they know what the appropriate speeds are for the conditions and then every time we had to prosecute for speeding it would have to go to court.

Surely having a limit to work within is better than that?

And I agree that busting someone over going at 33mph seems a bit extreme. But we have to have a "this is the fastest you can go in this area regardless of great the road conditions are" speed. It seems you merely want that to be higher, which is fine.


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PostPosted: Thu Nov 18, 2004 23:07 
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Mod,

Speed limits are an arbatrary number that may, or may not, be a reasonable maximum during certain conditions. In a residential area 30mph is, in most cases, probably a reasonable maximum during the day while people are about but when it's 2am and there's no-one about and the road is fairly wide and there is little or no other traffic, 40mph would not be unreasonable.

We have s school zone near us in a local street where the speed limit is 25mph. This seems reasonable at first, but this limit is applicable not just when children are coming to or leaving school, not just during school hours, but 24 hours a day. How is it dangerous to drive at 30-40mph at 2am? There are no children about then except the vandals setting fire to the school, and we don't want to run them over do we? What about on weekends when the rest of the local streets have a 30mph limit, is it unsafe to travel at that speed outside the school when no-one is there.

The same argument applies to road works speed limits when no-one is working and the road conditions are unchanged. Obviously if the road has been narrowed and/or emergency stopping lanes removed to make room for the roadworks the limit should apply 24/7, but what about the rest of the time?

In these circumstances, how is it fair that we get fined for doing 3mph over a limit that has no place for the conditions?

A speed limit sign, IMO, is there to indicate an average maximum safe speed in average conditions. When the conditions are better than average I go faster and when the conditions are worse than average I go slower. It's an indication, not a fixed speed over which the sky will fall!

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PostPosted: Fri Nov 19, 2004 01:07 
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M3RBMW, I agree! Speed limits are arbitrary numbers.

You would prefer then to have a variable speed limits? Speed limits which depended on the conditions of the road? Would you have two speed limits for each zone perhaps, an on-peak and an off-peak?

Would this not be confusing? The rules of the road in Bristol should be knowable if you are from Manchester. So arbitrary figures have to be drawn up at some point, in order to arbitrate when a person is considered to be going over the speed limit. In so doing, some speed limits may not be appropriate for some areas. How would this be dealt with? I suppose signs could be erected, at cost to the tax payer, for every time the speed limit changes? Probably a distraction in its own right.


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PostPosted: Fri Nov 19, 2004 01:22 
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Mod wrote:
M3RBMW, I agree! Speed limits are arbitrary numbers.


Mod, I think you're nearly there. Maybe you just haven't quite realised how little speed limits actually deliver yet.

I don't know if you followed the references I offered earlier, but I recommend the following:
http://www.safespeed.org.uk/why.html

If you think there's anything at all wrong on that page, please feel free to use its comment link and tell us exactly what it is.

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PostPosted: Fri Nov 19, 2004 01:30 
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What I suggest is that speed cameras have no ability to take conditions into account. If a camera was operating at 2am outside the school I was talking about and I drove a 30mph I would be fined. If a police officer was there and I was travelling at 30mph he/she would be very unlikely to do anything as it is obviously SAFE.

Get rid of cameras and get more police on the roads.

Police use discretion and in doing so gain the respect of the public. Cameras have no discretion and are considered by most to be a scourge on the road and this inevitably leads to a lack of respect for the police by the general public.

If you haven't seen any of my posts before please let me make something VERY clear. I do not condone dangerous or careless driving, in fact I wish there were more police on the road to catch these idiots. A camera cannot know what happened 10 feet before it or 10 feet after it. It's field of view is limited to one point and its only function is to check the speed.

More police, LOTS more police, and cameras limited to GENUINE black spots ONLY!

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PostPosted: Fri Nov 19, 2004 13:41 
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Once again I agree. Speed cameras do not take conditions into account.

Currently, the law stands that 30mph is the fastest you should go in a built up area...that 30mph assumes that the road conditions are the best possible. It sounds like you simply want to have that speed limit increased. Perhaps to 40mph. Obviously 40mph is clearly inappropriate in many situations, but a driver should be relied to set a safe speed within 40mph and there are probably very few areas where 50mph would be appropriate.

That's a fine campaign and I wish you luck with it.

At the end of the day, there is a maximum safe speed to drive at down a road in the best circumstances. I believe the speed limit should be lower than this speed. If you breach that speed by any degree, you are breaking the laws of the road. I do think that cameras picking people for doing 32mph is a bit harsh, purely on the basis that they might have mistakenly accelerated over the limit and be now decelerating.

My point stands: The speed a driver goes before an accident is proportional to the speed the driver is going at the time of the collision. The faster the collision occurs at the more damage is done. The more damage that is done the higher insurance premiums go/the higher the risk of injury or death.

If we say that 1/3 of all accidents occur through no fault of the driver (its probably higher than that), for example, somebody pulls out of a side road, or changes lane into them. In those kind of situations the driver has little time to react. If he is going 40mph when someone pulls out of a side road in front of him, the speed of the collision is going to be faster.

Using the highway code thinking distance indicators for simplicity: Lets say the guy pulls out 15 metres ahead. That gives us 3 metres before the point of impact. Less than one car length of braking is not going to reduce our speed a lot. Shall we say we hit at about 35mph?

If we were travelling at 30mph we have 9 metres of thinking time. 6 metres of braking time. I'd say that knocks us down to about 10-15mph.

The faster you go the harder you hit, in stark contrast to the information in the published article.


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PostPosted: Fri Nov 19, 2004 13:59 
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Mod wrote:
Most crashes happen at about 5mph


and

Mod wrote:
However, it is almost impossible to know what speed most accidents happen at.


:?: Either you know or you don't, so one of these statements appears to be untrue or at the very least somewhat ambiguous.


Mod wrote:
The frequency with which people tell me they were travelling at 27mph before the accident assures me that a good deal of those people were speeding


Or simply that they've been force-fed the "speed kills" message so often that they seem to think it'd be a good idea to claim a speed just below that magic 30 figure which the government tells us will guarantee a safe passage along our nations highways?

Alternatively, maybe they genuinely don't know the precise speed they were doing, but are pretty sure they were legal, so just put down "speed limit - 10%" as a generic response? Chances are I'd do the same, if I was being pushed into providing a specific figure rather than a more general answer - most of the time when I'm driving I can't state with absolute certainty what my speed is, but experience and observation is sufficient to let me know if it's varied by any significant degree since the last routine speedo check. So I might have been doing 30, I might have been doing 29, 28, 31, 27, 32... If I were absolutely certain that I wasn't deliberately exceeding the limit, and if the accident hadn't occurred at or immediately after a speedo check, then yeah, I'd probably give limit-10% as my answer if asked what speed I was doing.

Mod wrote:
combined with the large number of people which assure me that the other person was going far too fast.


Does that actually imply that people are speeding, or merely that most people find it difficult to judge with any great accuracy the speed of another moving object? If I'm behind the wheel, I have a pretty good idea what 30MPH feels like, but if I'm watching another vehicle drive past, I sometimes think 30 looks more like 40 - and since this sometimes occurs next to an active Gatso in a 30 limit, I know that these vehicles definitely aren't doing 40...


Mod wrote:
The government has set a maximum possible speed on all roads that conform to certain types with certain situations (schools, elderly people's homes etc).


Which local authorities are then free to meddle with as they see fit, resulting in comparable stretches of road in different counties having completely different limits.

Mod wrote:
In essence, you would create more speed limits, which are confusing and strange.


Exactly. Which is precisely what's happening in reality.


Mod wrote:
You would prefer then to have a variable speed limits? Speed limits which depended on the conditions of the road? Would you have two speed limits for each zone perhaps, an on-peak and an off-peak?


Why not? We already have variable limits on the M25, and it's my gut feeling that if we gave drivers the opportunity to travel at higher speeds in quieter times, they'd be more likely to respect the lower limits that applied when they were genuinely necessary. Having a low limit applied 24/7 because of a hazard which occurs for maybe 2 hours a day, Mon-Fri, school terms only, makes those drivers who use the road outside of these times resentful of the limit and more likely to treat it with contempt.

Mod wrote:
Would this not be confusing? The rules of the road in Bristol should be knowable if you are from Manchester.


No more confusing than travelling from one city which has 24/7 bus lanes to one which has time-limited lanes. Or travelling from one county which applies 30 limits only in the immediate vicinity of a village, to the next county which stretches those limits right out into the open countryside surrounding the village. Provided the limits are signed appropriately and drivers are made aware that the limits can and do vary according to time of day and road conditions, then they should be no more confusing than the fixed limits we have at present. If anything, they might even be less confusing if, as a result of going to variable limits, we end up replacing all the faded, badly sited, or missing signs that litter our roads at present, with clear new signs placed in accordance with the guidelines.


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PostPosted: Fri Nov 19, 2004 14:33 
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Quote:

Question Either you know or you don't, so one of these statements appears to be untrue or at the very least somewhat ambiguous.


Not really. We do not know the EXACT speed most accidents happen at. Largely due to the fact that people don't check their speedo immediately prior to impact, and if they knew they were breaking the speed limit they don't tell the police/insurance companies. Most incidents happen at or around the 5mph area. That could be 1,2,3,4,5,6,7 mph. We do not and cannot know for sure, the driver doesn't know for sure. I hope that clears that up for you.

Quote:
Or simply that they've been force-fed the "speed kills" message so often that they seem to think it'd be a good idea to claim a speed just below that magic 30 figure which the government tells us will guarantee a safe passage along our nations highways?

Alternatively, maybe they genuinely don't know the precise speed they were doing, but are pretty sure they were legal, so just put down "speed limit - 10%" as a generic response?


Precisely.

Quote:
Chances are I'd do the same, if I was being pushed into providing a specific figure rather than a more general answer


As would I. I never push them for a specific speed. I usually say "What kind of speed did the accident happen at/were you going at the time of the accident?". Responses such as "About 27 I guess" and "Between 25 and 30 I suppose" are fine. When someone says "I was travelling at 27 miles per hour", depending on context and the way they say it can seem very suspicious. Such suspicious answers are fairly common.

Quote:
Does that actually imply that people are speeding, or merely that most people find it difficult to judge with any great accuracy the speed of another moving object?


It doesn't prove anything. It many of these cases they are just trying to make themselves feel better no doubt, by putting some blame on somebody else, perfectly natural. However, at least some of these people are right.

Quote:
Which local authorities are then free to meddle with as they see fit, resulting in comparable stretches of road in different counties having completely different limits.


I don't see the problem with local authorities using their judgement in deciding on a speed limit. You think drivers should use their judgement as to what is safe, but the people who administer the roads should not do this?


Quote:
Exactly. Which is precisely what's happening in reality.



So you are pro what is happening right now then? You seem against local authorities deciding upon local speed limits, but you want speed limits to vary depending on circumstances? So you think this should all be administered by national government, and local government should have no control over the speed limits of their own transport system?

I am quite happy if you want variable rate speed limits. Lobby for it, speak to your MPs, the idea has merit. Hopefully a full and open debate will root out all the positives and the downsides, a local trial could be run somewhere and a decision to scrap it or go national could be made.


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PostPosted: Fri Nov 19, 2004 14:42 
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Mod wrote:
The faster you go the harder you hit, in stark contrast to the information in the published article.


Since I've been unable to get you to study the references, I'll build a basic case here.

1) Most drivers, most of the time are driving not crashing.

2) When things go wrong, nine times out of ten it ends in a near miss, not a crash.

3) Nothing in the preconditions can distinguish a near miss from a crash.

4) The average speed of an impact in an incident must, therefore, be very heavily influenced by the behaviour that allows most emergencies to be mitigated to a near miss. So for example if we have ten situations where a vehicle at 30 miles per hours is involved in an incident, we expect 1 impact at up to 30mph and 9 misses at 0mph impact. This clearly leads to an average impact speed of (9*0)+(1*30) / 10 = 3mph.

5) This sort of pattern persists whatever view of whatever crash statistics we examine. There are not enough high severity crashes to suggest that normal real world behaviour includes a significant proportion of crashes at free travelling speeds.

6) Ergo, the responses of road users to danger have a far bigger influence on average impact speed than free travelling speed.

Now the problem with cameras is that reducing the free travelling speed of traffic comes with side effects in driver attention and concentration. Since these latter parameters are proven to be more significant in crash avoidance than free travelling speed we should not be in the least surprised if vehicles at an enforced reduced speed have bigger crashes on average.

Now remember that we're talking about driver selected speeds, and that the average driver is responsible and trying to avoid crashing. In the large part he's set a safe and appropriate speed, be it above or below the speed limit. If we introduce drivers at grossly irresponsible speeds, then there's a massive increase in crash risk and impact speed. But those folk are not the ones affected by cameras.

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PostPosted: Fri Nov 19, 2004 14:53 
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I pretty much agree Paul.

However, the point remains unchallenged:

The faster you are going at the time you realize a collision might occur the faster you are going when that collision occurs, assuming a collision uccurs. Thus, the faster you are travelling, the harder you hit.

The article states:
Quote:
This is the "faster you go, the harder you'll crash" school of thinking.


and proceeds to say how this has a grain of truth to it. It is not a grain of truth, it is the complete truth. The faster you are travelling when an emergency happens, the faster you will be travelling when a collision occurs (and indeed the chances of you actually colliding are increased as well...) and the faster something travels in a collision the more damage it does.


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PostPosted: Fri Nov 19, 2004 15:10 
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Mod wrote:
The article states:
Quote:
This is the "faster you go, the harder you'll crash" school of thinking.


and proceeds to say how this has a grain of truth to it. It is not a grain of truth, it is the complete truth. The faster you are travelling when an emergency happens, the faster you will be travelling when a collision occurs (and indeed the chances of you actually colliding are increased as well...) and the faster something travels in a collision the more damage it does.


You are mentally holding "all other conditions" constant. But all other conditions cannot be constant. If a DRIVER is heading into danger at a lower or a higher speed, then WHY is he travelling at a lower or a higher speed? Has the alteration in his speed come with other alterations, for example to concentration or attention?

Now take three steps back and look at the comparative rarity of crashes. In fact the average driver causes an injury crash rather less frequently than once in 150 years. During that 150 years how many times has he "failed to crash"?

[edited to add this clarifying point]: If a driver has chosen a different speed then his mind has been altered to create the new behaviour. I say we can't EVER get that alteration without side effects, and some of the side effects are negative and dangerous.

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