CAUTION! Loop in road

Ferry · Post by **Ferry** » Sun Dec 30, 2001 22:14

Recently I've noticed lots of new loops appearing in suburban roads near where I live. Part of the bigger traffic planning picture I imagine. But that's not really my question. Why do they all the new roadside boxes have a big yellow stickers stuck on the top saying:
"CAUTION! Loop in road"
What's dangerous? I'm worried.

Thanks

Tom · Post by **Tom** » Wed Jan 02, 2002 19:51

<<Recently I've noticed lots of new loops appearing in suburban roads near where I live. Part of the bigger traffic planning picture I imagine. But that's not really my question. Why do they all the new roadside boxes have a big yellow stickers stuck on the top saying: "CAUTION! Loop in road"
What's dangerous? I'm worried.

>>

Loops are nothing to worry about - they're buried beneath the tarmac, and are simply loops of wire in which a small current is triggered by magnetic induction when a lump of metal such as a car passes over it. I doubt that any human (unless wearing a full complement of jewellery and having just eaten iron-richvegetables;-) ) would trigger a current, and even if they did there would be no danger (apart from the fact that they'd be walking in the path of traffic!).

The box of tricks at the side of the road (to which the loops are connected) is marginally more likely to be dangerous as there will be counting equipment inside, whichwould bepowered from the mains. However, the box should be watertight, and no more dangerous than a similar cabinet at a set of traffic signals.

I'm baffled, myself, unless you live in a rough area and the council have put these signs up to deter the local youth from vandalising them...?

Ferry · Post by **Ferry** » Wed Jan 02, 2002 23:17

Soory, I think I've dumbed down myself a bit too much! Actually, I'm a familiar with the whole loop type stuff. In fact, perhaps it's heresy to say it, I find myself much more interested in street furniture rather than roads these days! Now that is even more obscure.
That's what confused me about the warning. I know that the loops are fine and thery're everywhere anyway.
The other think that seems strange is that the message is a bit too technical. "CAUTION! Loop in road." What's a 'loop', you may ask. We know, but surely most people don't or even care!
(I must get out more and it's after midnight!)
Thanks

Tom · Post by **Tom** » Thu Jan 03, 2002 18:05

<<...Actually, I'm a familiar with the whole loop type stuff...>>

Sorry - I did wonder, but decided to give a short explanation of what a loop was just in case you weren't (and for anyone else's benefit).

<<The other think that seems strange is that the message is a bit too technical.>>

Yes - there are (IME) lots of over-technical notices like this in railway stations. Maybe the sign is for the benefit of workmen or something, but any workman worth his salt would surely notice the loop. I dunno.

<<"CAUTION! Loop in road." What's a 'loop', you may ask. We know, but surely most people don't or even care!>>

Very true - the HA seems to shy away from calling loops "loops" in their information pages (I can't remember where exactly, I'm afraid), preferring the mysterious "sensors". This, for me, conjures up images of infra-red stuff (eg Trafficmaster sensors) rather than relatively low-tech stuff like loops.

Better stop before I start rambling on about even more dull topics -- dull, that is, to anyone who doesn't confess an interest in street furniture