A single square pole instead of multiple round poles is used behind new signs.
Is that a fairly small square pole? I don't know how many of you are familiar with both, but just compare the typical American and British methods of mounting a simple sign (e.g. a single STOP or YIELD sign). The British arrangement is pure overkill.
You should try a Rhodesian (long now Zimbabwean) strip road. It's essentially a dirt road with a single one-car width of tarmac down the middle.
We have those in Norfolk, except the dirt portions to the side are known as fields!
Seriously though, there are a lot of back lanes only wide enough for one car.
people assumed they were secret codes put up to help UFOs find their way around town!
Yikes! They do look a little confusing.
Don't tell anyone, but I reckon they were the Irish branch of
THIS CONSPIRACY!