Black Ice

[Marc Brett]

All of the posts I've read on the Rhyl tragedy suggest that eeevil black
ice jumped outta the bushes and bit Harris in the ass, and nothing but a
constantly cautious speed could have prevented the crash.

I don't believe this is entirely true. Icy patches on roads /can/ be
predicted by an observant driver.

Cold air sinks, and so can pool in hollows, where ice may form. Marshy
areas are humid, and so may generate more frost in the area. Sunny
spots can melt ice, shady spots can preserve it. Bridges will ice up
long before the ground. Overhanging trees can inhibit ice formation.
Clear skies on a cold day are likely to form frost. Transformers on
poles are often associated with farms, and so the likelyhood of mud on
the roads. And corners, of course, demand extra attention. Careful
reading of weather reports can alert you to icy conditions, even if the
words are not mentioned in the report itself.

More here:

http://www.atmos.washington.edu/~cliff/Roadway.html

Of course, with GCSE-level physics not even requiring calculations these
days, the chances of even a small fraction of drivers absorbing this
sort of knowledge is sqrt(fa).

 

[mb]

Marc Brett wrote:

> Transformers on poles are often associated with farms, and so the
> likelyhood of mud on the roads.

Can't we just look for the fields/mud?!

--
Mike
Van Tuyl titanium Dura ace 10
Fausto Coppi aluminium Ultegra 10
Raleigh Record sprint mongrel

 

[vernon]

"mb" <[email protected]> wrote in message
news:[email protected]...
> Marc Brett wrote:
>
>> Transformers on poles are often associated with farms, and so the
>> likelyhood of mud on the roads.
>
> Can't we just look for the fields/mud?!

Nah it's much more satisfying trying to deduce what the road surfaces are
going to be like by inferences obtained from looking everywhere else but the
road.....

 

[Marc Brett]

On Thu, 28 Jun 2007 21:39:19 +0100, "vernon" <[email protected]> wrote:

>
>"mb" <[email protected]> wrote in message
>news:[email protected]...
>> Marc Brett wrote:
>>
>>> Transformers on poles are often associated with farms, and so the
>>> likelyhood of mud on the roads.
>>
>> Can't we just look for the fields/mud?!
>
>Nah it's much more satisfying trying to deduce what the road surfaces are
>going to be like by inferences obtained from looking everywhere else but the
>road.....
>
If you slowed down a bit, there'd be time to look for these sorts of
clues.

 

[Roger Merriman]

Marc Brett <[email protected]> wrote:

> All of the posts I've read on the Rhyl tragedy suggest that eeevil black
> ice jumped outta the bushes and bit Harris in the ass, and nothing but a
> constantly cautious speed could have prevented the crash.
>
> I don't believe this is entirely true. Icy patches on roads /can/ be
> predicted by an observant driver.

they can also be seen, black ice isn't magical it's just very clear ice.
so it can be hard to spot, but not impossible, a lot depends on if you
know what your looking at and if your attaully looking for it in the
first place.
>
> Cold air sinks, and so can pool in hollows, where ice may form. Marshy
> areas are humid, and so may generate more frost in the area. Sunny
> spots can melt ice, shady spots can preserve it. Bridges will ice up
> long before the ground. Overhanging trees can inhibit ice formation.
> Clear skies on a cold day are likely to form frost. Transformers on
> poles are often associated with farms, and so the likelyhood of mud on
> the roads. And corners, of course, demand extra attention. Careful
> reading of weather reports can alert you to icy conditions, even if the
> words are not mentioned in the report itself.
>
> More here:
>
> http://www.atmos.washington.edu/~cliff/Roadway.html
>
> Of course, with GCSE-level physics not even requiring calculations these
> days, the chances of even a small fraction of drivers absorbing this
> sort of knowledge is sqrt(fa).

roger

 

[Rob Morley]

In article <1i0gq11.1lw9wua1psdd13N%[email protected]>, Roger
Merriman
[email protected] says...
> Marc Brett <[email protected]> wrote:
>
> > All of the posts I've read on the Rhyl tragedy suggest that eeevil black
> > ice jumped outta the bushes and bit Harris in the ass, and nothing but a
> > constantly cautious speed could have prevented the crash.
> >
> > I don't believe this is entirely true. Icy patches on roads /can/ be
> > predicted by an observant driver.
>
> they can also be seen, black ice isn't magical it's just very clear ice.
> so it can be hard to spot, but not impossible, a lot depends on if you
> know what your looking at and if your attaully looking for it in the
> first place.
>
It basically looks like the road's wet, but your tyres don't make that
swishing sound and the steering goes light - it's not rocket science to
detect it.

 

[Alan Braggins]

In article <[email protected]>, Rob Morley wrote:
>In article <1i0gq11.1lw9wua1psdd13N%[email protected]>, Roger
>Merriman
>[email protected] says...
>> Marc Brett <[email protected]> wrote:
>>
>> > All of the posts I've read on the Rhyl tragedy suggest that eeevil black
>> > ice jumped outta the bushes and bit Harris in the ass, and nothing but a
>> > constantly cautious speed could have prevented the crash.
>> >
>> > I don't believe this is entirely true. Icy patches on roads /can/ be
>> > predicted by an observant driver.
>>
>> they can also be seen, black ice isn't magical it's just very clear ice.
>> so it can be hard to spot, but not impossible, a lot depends on if you
>> know what your looking at and if your attaully looking for it in the
>> first place.
>>
>It basically looks like the road's wet, but your tyres don't make that
>swishing sound and the steering goes light - it's not rocket science to
>detect it.

Yes, but if the ice is on a bend and you weren't going slow enough
_before_ your steering goes light and your tyres aren't making the
swishing sound, it's probably too late to do anything about it.
So either you need "a constantly cautious speed", or you need to
spot or predict it _before_ you are on it.

 

[Roger Merriman]

Rob Morley <[email protected]> wrote:

> In article <1i0gq11.1lw9wua1psdd13N%[email protected]>, Roger
> Merriman
> [email protected] says...
> > Marc Brett <[email protected]> wrote:
> >
> > > All of the posts I've read on the Rhyl tragedy suggest that eeevil black
> > > ice jumped outta the bushes and bit Harris in the ass, and nothing but a
> > > constantly cautious speed could have prevented the crash.
> > >
> > > I don't believe this is entirely true. Icy patches on roads /can/ be
> > > predicted by an observant driver.
> >
> > they can also be seen, black ice isn't magical it's just very clear ice.
> > so it can be hard to spot, but not impossible, a lot depends on if you
> > know what your looking at and if your attaully looking for it in the
> > first place.
> >
> It basically looks like the road's wet, but your tyres don't make that
> swishing sound and the steering goes light - it's not rocket science to
> detect it.

quite.

in the ryhl case no one else lost traction so totally, i dought the
traffic was that light that a car didn't pass though before probably not
10 mins ago.

the black ice oh nothhing you can do there isn't really a much of
argument

roger

 

[Rob Morley]

In article <[email protected]>, Alan Braggins
[email protected] says...

> Yes, but if the ice is on a bend and you weren't going slow enough
> _before_ your steering goes light and your tyres aren't making the
> swishing sound, it's probably too late to do anything about it.
> So either you need "a constantly cautious speed", or you need to
> spot or predict it _before_ you are on it.
>
I doubt that was the only patch of black ice on the road that morning -
he'd quite possibly driven over some on a straight bit and not noticed
because he was in too much of a hurry because he was late for work.

 

[David Martin]

On Jun 29, 4:39 pm, [email protected] (Alan Braggins) wrote:

> >It basically looks like the road's wet, but your tyres don't make that
> >swishing sound and the steering goes light - it's not rocket science to
> >detect it.
>
> Yes, but if the ice is on a bend and you weren't going slow enough
> _before_ your steering goes light and your tyres aren't making the
> swishing sound, it's probably too late to do anything about it.
> So either you need "a constantly cautious speed", or you need to
> spot or predict it _before_ you are on it.

How about slowing down before the corners where there might be black
ice? It seemed to work just fine for me in my years in Scandinavia.

It really doesn't add much time to the journey but it does take a bit
of discipline.

...d