(In case you can't read the writing on your screen, the left(-)hand sign says "Please go around" and the right(-)hand one says "Please go round".) I liked this bit of linguistic indecision.
Adverbial and prepositional round is far more common in BrE than in AmE. (And just typing it gets the Dead or Alive song going through my head. Which Dead or Alive song, you ask? You mean they had more than one? I thought they just released the same one over and over and over and over again.) According to John Algeo's British or American English?, round is 40 times more common in BrE than AmE (in the Cambridge International Corpus). Though it might just be differences in lexicographical practice, Algeo also notes that (US) Merriam Webster's Collegiate Dictionary (2003) lists 2 senses for prepositional round but 7 for around, whereas the (UK) New Oxford Dictionary of English lists 5 for around and 8 for round.
I searched for round the on the Guardian website and asked myself whether the examples I found would be round or around in my native dialect. Here are the results from the first two pages that didn't involve other Briticisms (otherwise I'd be typing explanations all day and night), repetition, compounding (e.g. a round-the-world ticket), or other disqualifiers:
- Party round the world in 2007
- Reading round the Christmas tree.
- He's an expert guide, fluent in Italian, takes you round the museum
- Pubs are to be allowed to stay open round the clock under plans for a radical overhaul of licensing laws
- 'Listen: tinkering round the edges will change nothing'
- On the way round the labyrinth, there are slits in the walls,
- He has recently completed the last section of a walk round the M25 [a motorway/highway]
Using Fowler's as a guide, The Grammar Logs of the Capital Community College Foundation (Hartford, Connecticut) answers a query about round and around with:
In almost all situations, the words are interchangeable and you'll have to rely on your ear to come up with the word that sounds better. [I]n British English, there are several idiomatic expressions in which "round" is obligatory, but where "around" would work just fine in the U.S.A.: "winter comes round," "show me round," "he came round to see me." In the U.S., "around" is obligatory when you're using it to convey approximation: "He arrived around 4 p.m.," "Around two-thirds of the faculty will retire next year."There are other idioms that must have one or the other in them--for instance to get around, meaning to go to/be in a lot of places (as in the Beach Boys song), needs around. But in the meaning 'to evade' (as in We got (a)round the security guard), BrE prefers round and AmE prefers around. Feel free to add your own examples in the comments!
An interesting example in the Guardian results was The speech heard 'round the world. Here the apostrophe seems to indicate the writer's feeling that round has been contracted from around--and probably the writer's feeling that round is a bit more informal. That was the only apostrophe'd one in the 20 I looked at. But is it round really a contraction of around? Maybe not. Around is a fairly recent addition to the language. The OED lists around as 'rare before 1600', and notes that it doesn't occur in the works of Shakespeare. Round goes back further, and Shakespeare used it in places where I would have said around (but he didn't ask me, did he?):
1602 SHAKES. Ham. III. ii. 165 Full thirtie times hath Phoebus Cart gon round Neptunes salt Wash.So where did the a- come from? It could be on analogy with other a- prepositions like across and among. At any rate, the OED marks its fourth sense for around as an Americanism now, but perhaps not in the past or the future:
4. In U.S.: = ROUND. Perhaps orig. U.K. (cf. quot. 1816). Now coming back into British use under U.S. influence.All this seems to indicate that apostrophes are unnecessary for 'round (at least in BrE), and that the perceived need to put them there may be analogous to 'til, which was till before it was until.
JANE AUSTEN Emma I. x. 187 Emma..was beginning to think how she might draw back a little more, when they both looked around, and she was obliged to join them.