Fog Signs on the Motorway - Who Controls Them
Discussion
Someone asked me this the other day and i thought that it would be a good informative thread, sorry if you already know the answer.
Sometimes you see the 'Fog' signs illuminated on certain stretches of Motorway and it does get a bit annoying when its during the day and theres bright sunshine and no Fog in sight.
Obviously the Police in the Motorway control room can operate them but on these occasions they are controlled by some other source and also overide the Police Controlroom.
Does anyone know how they are controlled and why they sometimes come on when it seems unnecessary?
Sometimes you see the 'Fog' signs illuminated on certain stretches of Motorway and it does get a bit annoying when its during the day and theres bright sunshine and no Fog in sight.
Obviously the Police in the Motorway control room can operate them but on these occasions they are controlled by some other source and also overide the Police Controlroom.
Does anyone know how they are controlled and why they sometimes come on when it seems unnecessary?
cptsideways said:
Automated systems: Two white bazooka like things that point at each other, often at foggy zones like dips & below hills etc. Cant think where I saw them last but often see them.
I assume they dont work very reliably
Back Scatter guns i think they are called, they detect the amount of light that is reflected back to them. usually just off the hard shoulder i think, I suppose heavy pollution at low height levels trigger them.
Gareth
edited to add: Dam everyone replied while i was writing mine!!
>> Edited by ^Slider^ on Monday 3rd November 18:12
gh0st said:
which leads to a lack of respect for the road signs so when the police really need them (for accidents etc) people will think "well its bollocks most of the time so it must be bollocks now"
All part and parcel of the country going to sh!t
Thats why i wanted to make sure that everyone was aware that its not always the fault of the Police .
That was interesting, I always assumed it was some dozy controller somewhere who'd turned them on and then went home for the day. Anyone got a picture of one of these things?
Also, while Tonyrec is explaining bits of road side furniture what are the gray boxes on the sides of motorways which have what looks like some tubes / pipes on top, usually pointing along the direction of travel? They're not cameras but are they some other sort of sensors? Not many of them around, I can only think of one on the M25 NW section and one somewhere (IIRC) on the M4, Eastbound somewhere west of Reading.
Also, while Tonyrec is explaining bits of road side furniture what are the gray boxes on the sides of motorways which have what looks like some tubes / pipes on top, usually pointing along the direction of travel? They're not cameras but are they some other sort of sensors? Not many of them around, I can only think of one on the M25 NW section and one somewhere (IIRC) on the M4, Eastbound somewhere west of Reading.
At one time (and I am going back a few years now) the Fog warns on the A329(M)/M4 used to be activated by Boeing 747's departing from Heathrow.
Apparently the engine frequency was exactly the same as we used on the hand held units to activate them by remote control.
Just a bit of useless information.
Apparently the engine frequency was exactly the same as we used on the hand held units to activate them by remote control.
Just a bit of useless information.
well a few things now i'm at uni. but always helpful 
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