So… if there's no maximum width for a bicycle (or cycle rickshaw, or whatever) how do they know how wide the contraflow lane has to be? And what happens if someone gets stuck?

It seems like a foolish omission. A motor vehicle is considered "abnormal" if it's wider than 2.9 metres, so presumably that's the minimum width they have to leave anywhere that doesn't have width limit signs. Shouldn't they have some similar reference point for bikes?

Hmm!