Safe Speed Forums

Hi All,

I'm doing some backgroud work trying to explain and understand the main underlying relationships between the parameters in the title of this thread.

I've been reading the literature and developing these ideas on and off for a couple of years. I'm getting ready to make some important assertions about a inverted U shaped relationship between speed and driver performance. The following provisional chart describes the relationship:



I've been reading the scientific literature - this recent and broad ranging document from NASA provides a foundation and an index:
http://human-factors.arc.nasa.gov/fligh ... 0Staal.pdf

This survey of Safe Speed visitors provides some weak evidence:
http://www.safespeed.org.uk/forum/viewtopic.php?t=117

My own personal experience provides the glue and the analysis that pulls it together.

This is supposed to be science at the layer of setting research objectives. The big problem with the existing literature is that few tasks enable those involved to adjust their own work rate and stress level, and few tasks require the uninterrupted long term vigilance required by driving.

Any comments, help with trawling the literature, evidence for or against the basic ideas, or anything related would be very welcome indeed.

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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

Have a read of the Roadcraft - The Police Driving Handbook, it has some interesting passages regarding this very subject.

They have made their conclusions already and I fear they are/will be diametrically opposite to the conclusions I predict will come from your research.

Find the Roadcraft Manual here: http://www.amazon.co.uk/exec/obidos/ASIN/0113408587/qid=1098545773/ref=sr_8_xs_ap_i1_xgl/202-3435504-1233457 Offered for guidance for what it looks like rather than as advertising.

I don't think you should be offering up your poll results as any sort of proof and think your comment "provides some weak evidence" rather overestimates it's validity. No offence.[/url]

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It's Champion Man

Here's something to be going on with, from your NASA doc page 66:

"The research literature concerning the effects of stress on perceptual-motor performance consistently
shows that these conditions tend to degrade performance. The negative effects of stress on
perceptual- and psycho-motor tasks have been demonstrated under a variety of conditions. Most
commonly this has been demonstrated using tasks of manual dexterity. Fine motor skills tend to be at
greater risk for impairment than gross motor skills."

Seems like this is supporting the impairment effect of an increase in stress, stress of course increases when the driver increases speed.

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It's Champion Man

It's by no means trivial to sift the existing research - there are plenty of overlapping effects that are not always separated from one another. And there's some rubbish research too - as one might expect with so many papers.

In this case they seem to be working on the upper part of the curve - not the lower - and their findings echo my hypothesis.



Except it simply doesn't cover what happens in the lower part of the curve. We don't normally term arousal levels between "comatose" and "medium" as "stress".

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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

I'm very familiar with Roadcraft, but not aware of anything that really goes to illuminate these questions. Quote a reference (chapter, page, text, scan, whatever)



I don't know of ANY OTHER EVIDENCE on the exact subject. That makes the Safe Speed straw poll, amazingly "the best evidence we have". As such it's damn important.

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

There's some good physiological stuff about:

http://www.reutershealth.com/wellconnected/doc31.html

Quote:

During a stressful event, catecholamines also suppress activity in areas at the front of the brain concerned with short-term memory, concentration, inhibition, and rational thought. This sequence of mental events allows a person to react quickly... It also hinders the ability to handle complex social or intellectual tasks and behaviors.

Maybe not quite what other research shows. Certainly, this demonstration is what I have always been led to believe.

Intereesting, thanks. Almost everything I've read about "stress" as such, works along the upper part of the curve.

Sometimes researchers find very high human performance levels at high levels of stress, and find a positive relationship between stress and performance (more stress, more performance). This positive relationship normally only seems to exist in short term tests, perhaps a few minutes of high performance.

These conclusions may be of interest analysing driving, and we may sometimes be able to do a little more than expected in an emergency situation as a result.

But I'm looking for the long term underlying relationships, not between stress (as such) and performance, but between arousal and performance and between speed and arousal. Performance in this case isn't concerned with emergency reactions, but instead should be concerned with sustained attention to the task and good decision making performance.

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

Hilarious

Stress is more likely to increase as a result of the thought of being late because you are travelling at an unrealistically low speed limit, set in an environment where you know that the slightest infringement of that limit will lead to 14 days of worry while you wait to see if the NIP will arrive.

Chumpion - you are a presumptious prat!

PS. The views of r11co regarding itschampionman do not necessarily reflect the views of SafeSpeed - OK!

Thank you very much for your greetings but I fear your analysis of the situation clearly indicates your intellectual capacity is below that necessary to carry out the required logical analysis to make a sensible statement regarding stress and speed relationships.
You would however be more suited to make statements regarding the character of others as you have here but that too is rather wide of the mark.
Just in case you missed the jist of the words above this too is a personal remark aimed at you.
I was tempted to say t*sser but though I'd give you something longer to read. It should keep you busy until the Beano Annual comes out at Christmas.
Cheers.

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It's Champion Man

Stress only increases when you exceed your comfort level speed. Until you reach your comfort level speed your concentration increases, with little or no stress. Each individual will have a different comfort level speed, based on their skill and perception of the hazards of the road. This means some peoples comfort level will be in excess of an arbitary speed limit, others will be lower.

Safe driving is not following an arbitary speed limit, this does not take into account the hazards present at the time. Speed limits should be a guidance, not a 'follow them or be prosecuted' rule. Dangerous driving should be prosecuted, be it above or below the speed limit.

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Regards

Kevin

Well, absolutely. The only problem is that there's no science to support the view. I'm trying to pull as much evidence as possible together in the hope of triggering some proper research.

How do you know what you wrote? By observing yourself?

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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

Not all my own post - my wife was sat next to me!

We could measure personal stress levels by just being aware of our normal comfort levels and comparing to them to those we experience each time we drive - extending and exploiting the diary theme.

We could even see how this compares with the ride on the roller coaster at the fair ground - where the speed seems faster than actual because of the nature of the ride ....


Trouble is - we all take some personal baggage with us each time we drive - which can affect us. Most of the stuff you can find on-line will tell you about stress, chronic stress, acute stress and all the medical, emotional and pyschological symptoms and causes. Disruption to bio-chemicals and especially serotonin (Also disrupted by taking of crack cocaine, speed, ecstasy etc) can take its toll on your driving standards.

But receiving medical treatment for external stress is one thing. I think we are after the stress to a "normal" average bloke when tootling along in his car and the stress velocity (or lack of velocity ) has.

For example - why do we let the "hurdler" (the one in the slow traffic who overtakes one car and slots into the your two second space) get us overwrought? Is it the "stress" of a long queue and the muppet at the back showing how to make progress? Or the consistent driver who drives at 40 mph in the urban area and at 40 mph when the road opens out to 50/60/70mph? Why do we get stressed when Chumps - our intrepid driver dares to speed up a bit, scares himself silly, and continues this erratic driving style - chuckling all the way to himself and at least preventing you from nodding off by treating us all to a light show of his brake lights (which are badly maintained of course and dazzle you with a most bizarrre flickering !).

Why is it that when we make progress and drive without hold ups and twazaks - our stress levels are normal? Perhaps the unimpeded journey ... which was enjoyable....

Perhaps children and elderly give some clues here. As regulars know - we drove to Switzerland last July. UK journey was the longest and most tiring timewise - as we were observing all speed limits (honest!). I found I was actually stiff and tired towards the end of the drive and the kids and one adult passenger fell asleep. In Germany - longer distance mile wise but faster and thus shorter time wise - all arrived alert and awake.

Perhaps watching our new baby in the car may give me further clues. The steady smooth motion of the vehicle seemed to cradle and rock this child in her baby seat. When she detected a slow down (or a speed hump ), fair old grisling (baby's way of expressing "stress") followed. Was it Papa's wonderful driving at 85th percentile which kept her cooing and gurgling away in the back the rest of the time?

Similarly our pet dogs - happy when in optimum traffic flow and motion, whimpering and restless when in slow moving traffic - yet will fall asleep in a jam.

I shall be watching and analysing my very normal and healthy family from now on.....

(Edited for odd typo)

Yes, and following conversations with others, who feel the same way.

As I've mentioned before I feel there are three groups of drivers on the road, we all fall naturally into one of the groups, they are:

1 Natural drivers, able to drive competently and safely, can usually drive anything they get into to a good level of competence.

2 Average drivers, able to get from A to B reasonably safely, but it is not a natural skill.

3 The remainder, who should not really be on the road, who have no idea what is going on around them and can be a menace to other road users. In general, how on earth did they pass the test?

My comment regarding concentration and stress definitely applies to the top group, and to some percentage from the second group, none from the third group.

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Regards

Kevin

"Thank you very much for your greetings but I fear your analysis of the situation clearly indicates your intellectual capacity is below that necessary to carry out the required logical analysis to make a sensible statement regarding stress and speed relationships.
You would however be more suited to make statements regarding the character of others as you have here but that too is rather wide of the mark.
Just in case you missed the jist of the words above this too is a personal remark aimed at you.
I was tempted to say t*sser but though I'd give you something longer to read. It should keep you busy until the Beano Annual comes out at Christmas.
Cheers.
_________________
It's Champion Man"





This from someone who cannot spell 'gist'!

Its intellectual snobbery now.....itsbullshitman

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Speed camera policy Kills

I did accuse itschampionman of being a presumptious prat because he imagined up a causal link between increased speed and stress, and then he went and proved how presumptious he is when he accused me, someone with postgraduate qualifications, of lacking "intellectual capacity".

Fake truths and false logic?? Is that your daily modus operandi??

I'll trust the judgement of the Universities before you, champ chump! Just because we disagree on issues of stress levels and increased speed DOESN'T, indeed couldn't give you the authority to judge anything else about me.

You just embarassed and undermined yourself again!

This thread has been dormant for a while but as I am a newbie I tend to read more than just the new stuff.... so here goes.

I occassionaly travel about 2 hours to get from my place to the Phillip Island race track so as to spend a day playing with my car in a safe environment. At the end of the day it's a long drive home with fairly boring bits.

As a test I travelled home once at and below the limit and nearly fell asleep. After about an hour I came to the conclusion that if I did not either stop or speed up I would crash. So I increased my speed to about 120kph (75mph) and was wide awake and alert for the remainder of the journey.

What I am eluding to here is that the first half of the graph perfectly mirrors my experience. I had no real desire to go over 120kph as it felt comfortable and was quick enough to hold my attention. It should be noted here that I was NOT tired, just bored, so stopping would have done little to alleviate the problem.

So what should I do, follow the posted speed limit and risk falling asleep or drive at a speed I feel comfortable with and maintain my concentration?

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Ross

Yes I'm a hoon, but only on the track!!!!

From my point of view, the question becomes: "What should the authorities do?". Should they force folk to drive outside of their zone of optimal performance or simply allow experienced and responsible drivers to do their best? Doesn't look like a difficult question to me - especially after one has stripped away the false assumptions about the "dangers of speed".

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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

Absolutely, so... get rid of the damn cameras and let the police do their job catching people who are driving inappropriately rather than exceeding an arbitrary limit by a few mph or even many mph if the situation permits.

I have been let off by police in a few situations where I have either not seen the speed sign but was still driving safely, or was over the highway limit but driving safely, with a warning. The police were really just checking on me to ensure my car was sound, I had a current licence and I appeared to be sober and attentive.

I was once booked for speeding in the inside lane on Christmas day by about 10kph (7-8mph) and I actually thanked the officer for booking me. I really was not paying attention and what a bloody stupid thing to do when at any time a kid on a new bike could come rolling out of a driveway. He thought I was taking the mickey but I REALLY meant it and slowed down and paid more attention after that. I deserved the fine AND the point and so how could I be upset by being pulled over!

Good system that, it works and I have full respect for the police concerned whereas I have no respect for cameras or their operators.

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Ross

Yes I'm a hoon, but only on the track!!!!

That's what I think too and that's what we're calling for. See:

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

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