Symbols on motorway signs

[motownman1]

What are the symbols on motorway signs for, they look like the type of deviation signs you see in towns?

[Numbers]

Can you be more specific? If you're referring to the yellow circles/squares/triangles sometimes shown, they signify diversion routes, an example being for A-roads that are liable to closure because of snow.

[motownman1]

but these are there permenantly Not for snow or whatever

[sddsddean]

If you mean the symbols that Lodekka describes eg black on yellow circles, squares, triangles etc, these are Motorway closure diversion signs. If the motorway has to be closed quickly (say due to an accident), the Police/Highways Agency only have to cone off the motorway at the slip road, unfold the sign on the slip road saying "For M1 North follow O " or whatever, and then it is up to you to look for the symbol on the normal, permanent signs to take you round the diversion. A very simple solution to negate having to put out loads of normal diversion signs.