Sign language can't beat real words

The thing is - and I did warn you that I was going to be a bit anal here - it's always true that the floor is slippery when wet, even if it happens to be dry at the time. They only put the sign up when the floor is wet, so it should just say "slippery".

In any case, the meaning is perfectly obvious from the outline diagram of some bloke going base over apex.

That ought to be enough; symbols, if properly designed, are clear and very concise. They can be understood subconsciously and do not need to be read in the way words do. Symbols are multi-lingual.

If a single symbol showing a man falling on his arse can do the work of at least four words, then it can be bigger on the sign and easier to see from further away. Symbols would seem to be the way to go.

Symbols certainly make sense inside the car. There are now fairly universal ones for on and off, for the petrol filler flap, for windscreen wiper intermittent setting, for the rear window heater, and so on

Little pictograms work as well in English as they do in Arabic or Chinese, which makes life much easier for button manufacturers.

Words have to be translated, and that means all buttons and switches would have to be big enough to accommodate the German.

For example, I think "intermittent wipe" might be "periodisch auftretend wischen", which explains why the column stalks used to be so big on Mercedes-Benz.

Outside of the car, though, I'm no longer so sure. Current British road signage has been very cleverly refined over the last 50-odd years and is a model of graphic fluency.

A handful of shapes and colours are enough to separate signs into warnings, advice and instructions, and stick men, umbrellas and Vauxhall Vivas falling into harbours do the rest.

But I've just been driving in America, and now I think words might have been better after all. We have a no-entry sign to warn us against the perils of driving the wrong way up a motorway slip road, but the Americans have a massive billboard bearing the legend WRONG WAY GO BACK.

I like the note of sheer panic in this, which seems perfectly suited to the magnitude of the error about to be committed.

The British sign seems to say "You are technically about to contravene a fundamental rule of The Highway Code". The US seems to be saying "Jeez you dumb-ass, use the other one".

There's a lot of this on US roads. I like a sign that says, "This is not an exit" in gigantic letters, because it speaks to me directly and personally, especially as I was thinking, "That looks like the exit there".

Elsewhere there might be a big arrow pointing to a line on the road along with the edict "Stop here". It wasn't entirely clear where to stop, but it is now.

Arrows painted on the road, like they might be here, indicate that the right-hand lane is only for people turning right. But you might miss those. You won't miss the sign saying "Right lane MUST turn right".

It's as if the Federal Department of Signage has recognised and accepted that most people driving cars aren't really that interested in what they're doing, and so should be spoken to in the only language they understand, which is the language.

A picture may paint a thousand words, but how, using symbols, would you alert people to the peculiar phenomenon that, in cold conditions, a short bridge becomes icy before the road leading to and away from it does? It's all to do with exposure to the air and the heat-retaining characteristics of the land, and certainly worth knowing.

You might be driving in near-freezing temperatures but satisfied that, despite this, the road is still perfectly grippy. But it might not be on the bridge, see? How do we get this complex idea across?

The answer is a sign reading "Bridge icy before road". Couldn't have put it better myself. Another version of this sign says simply "Bridge may be icy", but "may" is not such a helpful word. The bridge may have fallen down.

This is the one downside of a sign system based on words alone. Words can easily be equivocal, in a way that symbols rarely are.

Worse still, and as with the "slippery when wet" sign, they can enrage the latent pedant in all of us. I saw a sign that said "Be prepared to stop".

To be honest, this is good advice for life. I'm always prepared to stop. In fact I'm going to do it now.
--By James May,23 Sep 2010