I know that you guys in the States don't (yet) have too many of these, but they're ubiquitous here in the UK. Protocol is standard for these and generally cause no problems as long as us two wheelers adhere to lane discipline on the multilane approach versions.
This morning however, whilst ferrying young 'un over to his Module 2 riding test on the back of his KTM Adventure 890 I had a "moment" and wondered what you think?
Standard four exits island with 2 lanes (so 8 exits if you count the 4 no entries) and I'm approaching it to carry straight on. Driver in a white Fiat 500 approaching from my right to turn right and take the same exit as me. So far so good. As I get to the "give way" road markings I realise the Fiat is travelling too fast for me to safely merge ahead of them and so I brake to let them clear so I can slot in behind.
Now we get to the interesting bit. As I brake, so do they! This means I can no longer slot in behind, but draw alongside them on their nearside, still braking. It all got a bit messy and doubtless caused some irritation to following traffic who were held up slightly as we finally sorted ourselves out.
No real danger as such to anyone as we both had sufficient time to slow etc., but the lesson I took from this was the reminder never to assume that other road users will apply the same driving skills that you do. Had the Fiat maintained their momentum, then no drama. As it was, they did something I didn't expect - but should have! Always expect the unexpected and ride accordingly.