Driving at night

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The utility cyclist
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Re: Driving at night

Postby The utility cyclist » 10 Dec 2018, 10:26pm

Bonefishblues wrote:
SA_SA_SA wrote:
Bonefishblues wrote:....
I too can see less after dark, but let's not get into definitions of 'dark', let's just deal with the penalties.

But normal speed limits are set for daylight visibility:
the distance you can see in dark on dipped headlamps alone is much reduced* (and even on main beam which is also affected by the need to switch to dipped as needed meaning you don't want to big a disparity in speed). So lower night speed limits would simply recognise those facts....

Are they? I can see for miles and miles in the daylight, maybe they are too low? Yes of course I'm being devil's advocate, but with serious intent.

Sort the penalties and make the motorist drive to what he or she can see to be clear, irrespective of the condition, for mortal fear of transgression.

Most people will still drive in a certain manner because they know the chances of being caught are negligible, this has always been the same throughout history and it won't ever change, it simply can't change and trying to use the fear factor does not work, we know this already.

The only solution is electronic/mechanic restriction of speed on top of lowering the actual limits on the roads, also reduction of power and acceleration in all motors for everyone. Greater testing level and also removing people whom are clearly not mentally nor physically capable of being safe operating a killing machine, there are far too many of these types on the road whom are getting lucky every day, the odds are stacked because of that, as it is for many with too much power available to them amongst other factors.

Bonefishblues
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Re: Driving at night

Postby Bonefishblues » 10 Dec 2018, 10:35pm

The utility cyclist wrote:
Bonefishblues wrote:
SA_SA_SA wrote:But normal speed limits are set for daylight visibility:
the distance you can see in dark on dipped headlamps alone is much reduced* (and even on main beam which is also affected by the need to switch to dipped as needed meaning you don't want to big a disparity in speed). So lower night speed limits would simply recognise those facts....

Are they? I can see for miles and miles in the daylight, maybe they are too low? Yes of course I'm being devil's advocate, but with serious intent.

Sort the penalties and make the motorist drive to what he or she can see to be clear, irrespective of the condition, for mortal fear of transgression.

Most people will still drive in a certain manner because they know the chances of being caught are negligible, this has always been the same throughout history and it won't ever change, it simply can't change and trying to use the fear factor does not work, we know this already.

The only solution is electronic/mechanic restriction of speed on top of lowering the actual limits on the roads, also reduction of power and acceleration in all motors for everyone. Greater testing level and also removing people whom are clearly not mentally nor physically capable of being safe operating a killing machine, there are far too many of these types on the road whom are getting lucky every day, the odds are stacked because of that, as it is for many with too much power available to them amongst other factors.

You said that a few posts earlier.

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[XAP]Bob
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Re: Driving at night

Postby [XAP]Bob » 10 Dec 2018, 11:29pm

Bonefishblues wrote:
SA_SA_SA wrote:
Bonefishblues wrote:....
I too can see less after dark, but let's not get into definitions of 'dark', let's just deal with the penalties.

But normal speed limits are set for daylight visibility:
the distance you can see in dark on dipped headlamps alone is much reduced* (and even on main beam which is also affected by the need to switch to dipped as needed meaning you don't want to big a disparity in speed). So lower night speed limits would simply recognise those facts....

Are they? I can see for miles and miles in the daylight, maybe they are too low? Yes of course I'm being devil's advocate, but with serious intent.

Sort the penalties and make the motorist drive to what he or she can see to be clear, irrespective of the condition, for mortal fear of transgression.



Erm - yes because visibility *beyond* your stopping distance is irrelevant.
It's just that at night your visibility is *inside* your stopping distance, so an appropriate speed is vision limited, not performance limited.

Actually you can normally see further at night than during the day... The sun is only 93M miles away, the nearest of the stars you see at night...
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.

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Re: Driving at night

Postby Bonefishblues » 11 Dec 2018, 8:49am

[XAP]Bob wrote:
Bonefishblues wrote:
SA_SA_SA wrote:But normal speed limits are set for daylight visibility:
the distance you can see in dark on dipped headlamps alone is much reduced* (and even on main beam which is also affected by the need to switch to dipped as needed meaning you don't want to big a disparity in speed). So lower night speed limits would simply recognise those facts....

Are they? I can see for miles and miles in the daylight, maybe they are too low? Yes of course I'm being devil's advocate, but with serious intent.

Sort the penalties and make the motorist drive to what he or she can see to be clear, irrespective of the condition, for mortal fear of transgression.



Erm - yes because visibility *beyond* your stopping distance is irrelevant.
It's just that at night your visibility is *inside* your stopping distance, so an appropriate speed is vision limited, not performance limited.

Actually you can normally see further at night than during the day... The sun is only 93M miles away, the nearest of the stars you see at night...

I drive way beyond my stopping distance in order to make safe progress.

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[XAP]Bob
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Re: Driving at night

Postby [XAP]Bob » 11 Dec 2018, 11:30am

Bonefishblues wrote:I drive way beyond my stopping distance in order to make safe progress.


Erm - I think you need to look up the meaning of the word "safe"
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.

Bonefishblues
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Re: Driving at night

Postby Bonefishblues » 11 Dec 2018, 11:33am

[XAP]Bob wrote:
Bonefishblues wrote:I drive way beyond my stopping distance in order to make safe progress.


Erm - I think you need to look up the meaning of the word "safe"

Welcome some help in that area :D

AlaninWales
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Re: Driving at night

Postby AlaninWales » 11 Dec 2018, 1:39pm

Bonefishblues wrote:
[XAP]Bob wrote:
Bonefishblues wrote:I drive way beyond my stopping distance in order to make safe progress.


Erm - I think you need to look up the meaning of the word "safe"

Welcome some help in that area :D

I drive way beyond my stopping distance. Thinking only of what is in your stopping distance means being unable to utilise that distance because the hazard has not been noticed before it enters the stopping distance. Driving within the stopping distance is unsafe.

Bonefishblues
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Re: Driving at night

Postby Bonefishblues » 11 Dec 2018, 1:48pm

AlaninWales wrote:
Bonefishblues wrote:
[XAP]Bob wrote:
Erm - I think you need to look up the meaning of the word "safe"

Welcome some help in that area :D

I drive way beyond my stopping distance. Thinking only of what is in your stopping distance means being unable to utilise that distance because the hazard has not been noticed before it enters the stopping distance. Driving within the stopping distance is unsafe.

We are in violent and complete agreement Alan :D

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[XAP]Bob
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Re: Driving at night

Postby [XAP]Bob » 11 Dec 2018, 2:56pm

So you drive within your stopping distance, and observe beyond.

The point here being that stopping distance is not just a function of tyres and surface, but of how far you can observe. If you can only see five feet then you need to be able to stop in less than half of that.
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.

Bonefishblues
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Location: Near Bicester Oxon

Re: Driving at night

Postby Bonefishblues » 11 Dec 2018, 3:18pm

[XAP]Bob wrote:So you drive within your stopping distance, and observe beyond.

The point here being that stopping distance is not just a function of tyres and surface, but of how far you can observe. If you can only see five feet then you need to be able to stop in less than half of that.

As far as I can see (see what I did there?) we are agreeing. Is there no possibility we could book an argument? :o

pwa
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Re: Driving at night

Postby pwa » 11 Dec 2018, 4:27pm

[XAP]Bob wrote:So you drive within your stopping distance, and observe beyond.

The point here being that stopping distance is not just a function of tyres and surface, but of how far you can observe. If you can only see five feet then you need to be able to stop in less than half of that.

That is assuming there is someone coming the other way at a similar speed but without lights? If they had lights you would expect to see them earlier even though they are not lit by your own lights. Pedestrians and stationary objects are obviously not going to be coming towards you at significant speed so being able to stop within the distance you can see ahead is fine.

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Re: Driving at night

Postby Bonefishblues » 11 Dec 2018, 4:33pm

See, react and stop, being pedantic, but yes

pwa
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Re: Driving at night

Postby pwa » 11 Dec 2018, 4:40pm

I raise the point because when driving in darkness one of the things I am alert to is oncoming lights, either seen directly or lighting up things such as hedges, giving advance warning that something may be coming the other way. Truly unlit objects / people/ animals are generally slow moving, to the point where being able to stop within the distance you can see to be clear is adequate.

As I've said before, the only time I have gone into something in the dark was when cycling, and the object was a large black bullock that my eyes mis-read as a shadow.

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Re: Driving at night

Postby MikeF » 11 Dec 2018, 10:57pm

pwa wrote:
As I've said before, the only time I have gone into something in the dark was when cycling, and the object was a large black bullock that my eyes mis-read as a shadow.
The same could apply to someone driving a motor vehicle. A friend of mine did that. If the black bullock had been a person the result might be the same.
"It takes a genius to spot the obvious" - my old physics master

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[XAP]Bob
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Re: Driving at night

Postby [XAP]Bob » 11 Dec 2018, 11:52pm

pwa wrote:
[XAP]Bob wrote:So you drive within your stopping distance, and observe beyond.

The point here being that stopping distance is not just a function of tyres and surface, but of how far you can observe. If you can only see five feet then you need to be able to stop in less than half of that.

That is assuming there is someone coming the other way at a similar speed but without lights? If they had lights you would expect to see them earlier even though they are not lit by your own lights. Pedestrians and stationary objects are obviously not going to be coming towards you at significant speed so being able to stop within the distance you can see ahead is fine.


I've seen enough vehicles without lights that I'm not relying on that ant more (I used to).
1/2 is probably overkill, but that depends on the speed you are doing... I'd assume anything might be approaching at 20mph (cattle can easily do that). But I'd rather be thinking 1/2 and let it slip to 2/3, which is probably still OK, than thinking 2/3 and letting it slip to 5/4...
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.