Safe Speed Forums

It is extremely easy to blip over in all kinds of traffic conditions, unless you devote such attention to the speedo that you're paying less to everything else.


Given the inherently very imprecise nature of speed limits as a representation of a safe speed, even when not set for political reasons, do you honestly believe that absolute speed limit compliance is of major relevance to safety?

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"Show me someone who says that they have never exceeded a speed limit, and I'll show you a liar, or a menace." (Austin Williams - Director, Transport Research Group)

Any views expressed in this post are personal opinions and may not represent the views of Safe Speed

Note the qualification "necessarily".



How can they? Have the looked at all the facts?

Maybe so.

Is it easy to continue pass a diamond-grade backed speed camera or marked van at the speed limit + 10% + 2 + speedometer error?


Not absolute, but but speed limit compliance should be expected, and only so much tolerance should be given for transgression. Why? Because where speed limits are there because drivers cannot reasonably be expected to work out what the safe speed is (or where they are just failing to do so) then you need people to respect the limit, and not think they know better.

Its the same situation as at traffic signals. It may well be safe for a driver to run a red sometimes - but you need them to obey so they obey when it isn't safe, and when the fact it isn't safe isn't necessarily apparant.

How do you judge when you're doing a safe speed?
If you can't answer that, or if you relinquish responsibility for that judgement to whatever the round signs say, then you really shouldn't be driving.

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

Thats missing the point.

I'd like to know how you determine the safe speed when there are hazards which cannot be observed or assessed. Or how you can be so sure you can see everything you need to see. Or that you are actually getting it right.

People clearly have difficulty - they wouldn't drive past cameras at above the speed limits if they didn't.

The most important aspect of driving is surely recognising ones fallability. I know I'm not perfect - which is the most important thing I know.

Such locations do exist, but they are comparatively few and far between. It's precisely those locations where speed limits - or other effective warning signs - are really needed.



Oh come on now. When have you ever seen a camera situated at one of the abovementioned locations?

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

How would you know?



How would you know?

And thats missing the point - if drivers can't cope with marked and signed cameras and camera vans, how are they going to cope with subtler hazards?

Just how long have you been driving?



Ever considered that they could be too busy looking out for real hazards?

Edited to add: In locations where genuine hidden hazards exist, if you're going anywhere near the speed limit you're probably way too fast - just BTW

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

You seem to have a remarkably charitable view of the visibility of both fixed cameras and Talivans. Quite a lot of fixed cameras are not at all obvious the first time you drive along a road:



Yep, there's one lurking just behind the bridge.

Talivans have a variety of liveries that are often not really clear, and also are often deliberately parked in inconspicuous locations. See the Talivan pages on www.speedcam.co.uk

Even a clearly visible Talivan can easily look like all sorts of other kinds of white van. You end up being suspicious of every white van you see by the roadside or on an overbridge.

Once you get to drive a bit more on unfamiliar roads you'll realise what I mean.

_________________
"Show me someone who says that they have never exceeded a speed limit, and I'll show you a liar, or a menace." (Austin Williams - Director, Transport Research Group)

Any views expressed in this post are personal opinions and may not represent the views of Safe Speed

How long have you been traffic engineering?



HTF are drivers supposed to work out if a hazard is real or not if the don't look for and see all hazards so they can assess if they are "real" or not?



Quite possibly.

But then maybe thats why you think the speed limits are often too low.

One has to wonder

a) what else is lurking behind the bridge and

b) given the visibility is crap, surely those doing 35+ through that bridge are driving dangerously and deserve to be prosecuted?



Nevertheless, they are all somewhat better marked than the majority of other hazards.

The country is littered with examples of how traffic engineers don't seem to know the first thing about driving.

And unless you have driven and frequently encountered the things in unfamiliar locations, you simply do not know how visible speedcams and Talivans really are, and how drivers (even if travelling below the limit) actually react to them.

_________________
"Show me someone who says that they have never exceeded a speed limit, and I'll show you a liar, or a menace." (Austin Williams - Director, Transport Research Group)

Any views expressed in this post are personal opinions and may not represent the views of Safe Speed

They're usually clearly marked in the sense that a Dyno-Rod van is. But NOT clearly and uniquely identifiable from within the distance they can snap you as Talivans. That's if they even bother to park in the open, which they often don't.

And how is this visible or distinctive?

_________________
"Show me someone who says that they have never exceeded a speed limit, and I'll show you a liar, or a menace." (Austin Williams - Director, Transport Research Group)

Any views expressed in this post are personal opinions and may not represent the views of Safe Speed

Examples?

(Cue Broadstone Road, Stockport)

And of course, driving isn't the only issue. Everyone else has to be catered for as well.

And thats before political pressure, pressure from developers, from pressure groups, from individuals who think they know best, etc, etc.



Indeed - but the cameras are still an awful lot more visible than alot of other hazards. As I pointed out in your last example, if you can't see the camera, what else can't you see?

If you can't see them parked up you won't be able to see them if they decide to pull out in front of you. So slow down.



Is it typical?

And I suspect it would be somewhat more obvious when viewed from the driver's eye, with operator and equipment visible.

I don't accept that they are unless you know exactly what to look for and are actively looking out for them.

I am a member of the IAM and have 25 years and over 300,000 miles of conviction-free driving. And take it from me that if you want to make sure that all drivers spot cameras and Talivans sufficiently far in advance, then they are nowhere near visible enough. I'm sure many of the other regulars here will back me up on this.

Why don't you argue that every single fixed camera should have a specific warning sign between 200-300 yards in advance of it, and likewise every single Talivan location when the van is active? Absence of such a sign would invalidate any prosecutions. That would achieve the visibility you are claiming exists but in fact doesn't.

_________________
"Show me someone who says that they have never exceeded a speed limit, and I'll show you a liar, or a menace." (Austin Williams - Director, Transport Research Group)

Any views expressed in this post are personal opinions and may not represent the views of Safe Speed

If you're a traffic engineer then perhaps you can enlighten us on how limits are worked out.
And perhaps you can explain the logic behind the following:
Not far from where I live is a major 'A' road which, until about a year ago, was NSL. This road had no history of accidents, except at one notorious junction where several accidents occurred on dark, rainy mornings because of poor visibility. They solved the visibility problem by cutting back overgrown vegetation near the junction. Then they put up traffic lights - which now cause mile-long tailbacks, where none existed before.
Not content with these measures, they then reduced the speed limit to 40mph for about two to three miles either side of the junction.
Another road near me is also a major route into town. It was NSL until a few years ago when they reduced it to 40. Also no history of accidents, except for one drunk who got killed crossing the road from a pub late one rainy night. Admittedly, people did have a problem crossing the road - but that was down to the sheer volume of traffic in the morinings and evenings. So they put up a pelican crossing. Problem solved - or so we thought. A few months later the limit was reduced to 30 - not just in the vicinity of the crossing, but for the entire length of the road. We now have serious congestion, where the traffic used to flow reasonably smoothly.



So you consider a van parked half-hidden in a layby alongside a dual-carriageway to be a hazard then? Or one parked on a motorway bridge?
And since when do you look for hazards several hundred metres ahead? But at those sort of distances, they've already nicked you - even if you haven't yet been able to make out what colour the van is.

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

No-one actively looks out for a specific hazard (how would they know which hazard to specifically look out for?) They look out for hazards generally.



But thats not the point. The point is people should be driving with caution so they can deal with hard-to-spot hazards. Speed limits are there to tell people what the maximum speed as one mechanism to ensure they don't drive too fast (or at least if they do, they don't do so by too large a margin). Enforcement is there to help encourage drivers to keep below the limit, even if they think they know better.

My original point re drivers having difficulty identifying cameras and camera vans was merely an example of the difficulties drivers face in identifying hazards generally. Not all hazards are necessarily apparant to the driver.

Guidance, and democracy being what it is, influence from the public, pressure groups and politicians.

You don't need to be a traffic engineer to work that out.



Of course I can't. You haven't specified the nature of the road, traffic speeds, alignment, sightlines, traffic volumes and turning/crossing counts, accident record etc, and as you haven't so much as specified the road I have no way of finding out any of that.

I can point out some of the possible flaws in your argument though.



How do you know?



How do you know?



Did that solve the accident problem?

Did it create a new accident problem?



Maybe improving visibility didn't solve the accident problem?

Maybe the signals are gating traffic and relieving traffic a some point further along that may be more critical?



Maybe the signals didn't solve the accident problem.

Maybe the sightlines or geometery couldn't be provided for 60mph approaches.

Maybe the speed limit was wrong in the first place.

Maybe idiot drivers were just managing to crash in completely unfathomable circumstances, and so reducing speeds was an attempt to reduce the consequences when people did manage to drive into each other.



Maybe the speed limit was too low in the first place?



How do you know?



What were the circumstances?



Maybe there was an accident problem. Maybe the 40 limit was too fast.



How do you propose the speed limit changes were responsible for this?



Potentially, yes.

Do you assume it won't pull out?

And if it's half hidden, there may be something I can't see in the layby which may wish to pull out.



Granted



On motorways Roadcraft suggests looking at least 1/2 mile ahead.



Again, you've missed my point. See my reply to Peter.



It seems you have already prejudged the motivation for the changes you have described.

If there was really a danger of something lurking behind the bridge, then surely a 30mph speed limit there is hardly sufficient.
Just imagine that you're driving along that road at just under 30mph, and when you're already under the bridge a pedestrian runs out from behind it. Are you going to be able to stop in time? Not on your nelly! You probably won't even have time to get your foot onto the brake pedal.



Not at the distance that they can nick you from. You scan for hazards up to a few seconds ahead of you, not a few tens of seconds.

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