Because I'm an arse, and still haven't got those pictures I was on about, here's what Google SV has to offer on the matter of the ones east of Hull, UK, on the way to Spurn Head Spit.
Heading on the west bound direction, looking north (its a double bend). You can see the properties and their loops in the pavement. Basically, they know to look left out of the drive if its green, and both ways if its red. It doesnt get much more helpful than that, really in this case, and as you see, despite getting the green at the stop-line, they've gone back to red (the van behind the SV car says which way it was travelling, and therefore why its passed a green, and then got this red), which could make someone stop in the middle of the double-bends when they see the repeaters. If it is for the drive - IMO, providing one for each drive on a pole on the grass between the two drives, facing at the drive, with their own stage would be best. I'm assuming they're for drives of course, otherwise I really don't see their point.
Then there's this, which makes slightly more sense, as its set up like I said it should be in the above paragraph. The right one still doesnt have its own stage however (acting in the same way as the first), and the one to the left seems wholly pointless being mounted under a standard RAG which shows the same indications as the mini one below (opposite to that of the right one and first one).
All just
