Safe Speed Forums

No it isn't. As the statement implies, it is only impossible whilst development is based upon "knee jerk" reactions. If development were properly planned, against genuine priorities rather than hidden political agenda, then positive development becomes easily attainable.

The town where I live is a case in point. It has a by-pass that circumvents one side of the town, but the main industrial areas are on the opposite side, along with two A roads. It also has a tortuous one way system, so the net result is that lorries and through traffic has to go through the town centre, causing all sorts of problems.

It is readily apparent from any honest appraisal that the required solution is to add a further relief road, so that the through traffic can go round, but that seems not to be politically acceptable, for various reasons.

So the "solution" was to spend hundreds of thousands of pounds re-directing the one way system so that all the traffic goes in different directions to before. The result is that the same traffic is making the same trips through the town, but via different roads, so there is broadly as much congestion as before but in different places. Of course this was done as a "six month trial", but the engineering put in place to achieve it was permanent from day one, which speaks volumes.

Now the "next step" is to pedestrianise the main street, and again it is claimed that this is to be on a "trial basis". Someone wrote to the local paper the other week and suggested that if this were genuinely the case, why don't they simply cone off the street and put some temporary signs up, in order to assess the impact? What a damn good question! Instead a permanent solution will be put in place from day one, as there is clearly no intent whatsoever of ever reverting from the "trial" system.

This is what happens when political objectives are allowed to dictate policy. It seems clear that the primary objective is to try and rid the town centre of traffic, but without offering any alternative. No handy "park and ride", no by-pass for through traffic, no cheap and plentiful "perimeter" parking zones, no improved rail connection, nothing. So the net effect will be to decimate the town's trade, whilst worsening congestion and delay as the through traffic is faced with no option but to queue up and force its way through the one way system.

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Tosh! It would be so nice if safety were the only concern in a system. You are engineer, so you are aware that in the real world, cost is a major concern too. While you may wish that this was not so, there is nothing controversial for you in this – it’s simply realpolitik that all stakeholders must have their say, and relatives costs and benefits for all have to be considered.

Now please give me the details on how 85th percentile is measured on a part of road, if you know.

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Fair comment, but what incorruptible entity decides genuine priorities from bogus ones? Who is the impartial judge of these matters? How do we compel this judge to be accountable for his or her decisions, and what factors does the judge use to arbitrate? Safespeed fairly asserts that safety towers high over all other factors, except cost, of course. Yet his definition of safety is a narrow one. Also included (in the bigger picture at least) should be the health and well being and happiness of all the people involved. Or are these are just “sensibilities”, which should not be considered at all?

I sincerely would like to know how you think these issues of group concern (i.e. political ones) should be settled.

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Maximum safety and minimum cost are very well aligned in the subject under discussion.

Isn't it obvious how speed survey data is gathered? Some piece of automated kit is left by the roadside and data logs speeds of passing vehicles.

It's possible that sometimes the 85th percentile speed won't be optimal, but in such cases an engineering solution is usually indicated.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

But isn't that a bit Heisenberg? I mean, the drivers being observed are subject to a speed limit while they are driving by. That must have an effect of slowing the traffic and giving 'false' data. To find a natural 85 percentile, surely you must have an isolated experiment?

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There might well be an "interference effect" from policy. That's a damn shame. However, despite policy, most drivers are still setting appropriate speeds according to the conditions and that's what really matters.

There are very few places where speed limit compliance is so marked as to have a massive effect.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

Drivers could set a speed that is appropriate for thier objectives (speed and thier own safety), rather than the combined objectives of both drivers and residents (low-speed to create safety for residents, and other road users, and peace and quiet and less smoke in the village)? Isn't there a fundamental tension with the 85th percentile? And how should it be released?

With respect to the 85th Percentile, when you define 'safety', do you consider long term effects on people's health due to lack of safe walking and cycling space, and pollution? Or do you just count the safety issues that are immediately obvious to you as a driver?

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That's safety before sensibilities again. "Low speed" doesn't in itself create safety, and sometimes increases danger. Average crash severity in 20mph zones is greater than average crash severity in 30mph zones, for example. We need to know why.



I don't believe that any such "tension" exists in any normal place. There are abnormal places that need special treatment. Where a tension is perceived it's usually something happening within the fastest 5% (nutters!) or it's a mis-perception.



I concentrate heavily on road safety. (i.e. how to have fewer crashes)

Those other considerations probably already have far too many advocates and I don't need to add to the racket.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

Could this be this arse-backwards? One might argue that zones have 20mph limits because crash severity is worse there than other areas.



Do you class fear and stress of powerful, heavy, noisy, smoky objects whizzing by as mis-perception?



The matters are related and cannot be separated. You may not wish to promote health and well being before your own objectives, but the issues still exist. Your restricted position sounds strangely similar to that of drivers, who wish to use a road through a village but not to consider the consequences for residents.

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Like I said, we need to know why. I strongly doubt your proposed explanation.

If I had such a responsibility, there's no way on earth that I'd sign off a 20mph zone until we know far better what we're doing.



Frequently, and if unassociated with crashes, absolutely.



Cannot be separated? You're quite mad!

Road safety is easy to measure - count up the deaths and injuries from crashes. It certainly isn't just a matter for drivers, but for all road users. I disapprove of schemes that "move the casualties around". I wouldn't like any scheme that saved pedestrians but killed drivers or the other way around for example.

I'm proud that my focus is on fewer crashes. That's what I specialise in. Others are free to choose their own specialisations.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

Safety: the condition of being safe from undergoing or causing hurt, injury, or loss.

Hm, how remiss of you, SafeSpeed - you seem to have left out the cost of "loss" from your calculation - that's why it is easy. Now, think of all the things that we have lost because of car domination, and you will find that road safety is not so easy to measure after all!




I approve of schemes that move the risk from the victims to the person who causes it. For cameras, the risk is financial, but at least there is some deterrent. That's not mad, that's the right thing to do, because if you are the person who causes risk to others, you are also best placed to prevent it.

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This is a wind up, right? Remiss? I should coco. This is one line of a forum post not a full examination of all the issues.

However, as it happens, any policy intended to reduce injury on the roads will also tend to reduce the costs of crashes. At some layer we need to compare the cost of policy to the benefit in terms of crash reduction, but there are loads of more-or-less zero cost policies - like telling the truth or making better use of existing traffic police. When we run out of zero cost policies there will be some careful thinking to do.



I've never seen a road safety scheme that moves risk from victim to causer (as far as I know). We seem to have a common perception that pedestrians are victims but reality differs in as much as most pedestrian impacts are held to be the fault of the pedestrian.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

That's neat! In your world, we have only victims and faulters, and no mention is made of the inherent dangers of heavy chunks of steel whizzing around at high speed, controlled by monkeys! And you say I'm winding you up. Ha! Don't make me laugh!

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There are plenty of other examples of machinery being in close proximity to the public....look at the London Underground.

We cannot hold others responsible for our safety if we are not prepared to look out for ourselves.

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Speed camera policy Kills

There's inherent danger in life. There's inherent danger in transport. There's even inherent danger in getting out of bed in the morning.

So what are we going to do? Ban transport? Ban life?

No. We're going to take an intelligent approach to managing and minimising the danger. Well, what do you know. That's what I do.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

No, let's keep it simple for a minute. Do you expect people to believe that your speed and your risk are not related? Do you expect people to believe that cars are not dangerous? Do you expect people to believe that it's "OK" when people get knocked down if they have a momentary lapse, because it's their own fault? Do you expect people to believe that cars don’t spew out pollution and noise, and take up more space than they should and uglify the landscape?

No, cars are not nice. Read that again, please – cars are not nice! But we need them, so we won't ban transport - we'll ask politely that all drivers show due respect for other persons.

And if they can't see their way clear to do that, we'll beg them to collectively show some respect for other persons.

And finally, failing that, as an absolute last resort and were very sorry to put you out and all that, but finally, well, maybe something more intrusive than appealing to their good natures (or lack thereof) is necessary to force a culture change. And I’m very sorry about it, I mean I could get pinged myself!

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First of all, as:


The corollary is that most people actually drive as well as you do, or at least as well as you think you do.

The 85th percentile speed is chosen using a massive poll of all the road users after filtering out not just the dangerously and inconsiderately fast, but also even the best drivers.


Secondly the more local the road is, the more locals you have using it:

This is one of the reasons why setting speed limits by the 85th percentile rule works so well:

Massive local knowledge, experience and input into speed limit setting.

Automatically.


On the contrary.

As you've just helped me prove:

The 85th percentile speed on local roads is set by local stakeholders.

The 85th percentile speed on fast "cars only" roads, motorways, etc is set by non locals who are the stakeholders for the trunk routes.

Or are you complaining that somone who has bought a house on the A1 isn't allowed to have a 20mph limit enforced on his doorstep?

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They aren't being observed, just their speeds recorded.

And dozens (hundreds?) of studies have shown that traffic speed is pretty much unaffected by speed limits in the absence of draconian enfocement.

Yet another reason for using the 85th percentile rule:

The law should not criminalise the actions of the overwhelming majority of safe, considerate and generally law abiding citizens.

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You are confused between discussing the matter, and discussing ourselves. BTW: Are you accusing me of thinking I am a good driver!





I bolded some of the above, so show you where you are wrong. Indeed, if pedestrians were included in the 85%ile, then I would whole-heartedly agree with the approach, because a limit of 10 mpg would be in the offing! But alas, it is selectively restricted to car drivers!



No, there is a weight of history behind the A1 situation. What has to stop is further deterioration of rights, although I also hope there might even be improvements, after the age of car tyranny is over!

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Can you be generally law abiding without abiding by some of the laws? Perhaps someone would be generally law abiding, apart from some dope smoking/speeding/littering/pissing in the bushes/trespassing/stealing and otherwise screwing around in a dozen minor ways. Doesn't make it a good idea, though, does it?

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