Zip merging: taking turns when a lane ends

Your lane is ending. You merge straight away, because squeezing in at the last moment feels rude. But that's what everyone does. One lane is completely full, and the other one stays empty. What does the CBR say? This is called zipper merging. You merge in turn.

One from the left, one from the right. Just like the teeth of a zip. It only works if the through lane makes room. One car at a time. Are you the one merging? Then you give way. So merge calmly when there's room. You do this in a traffic jam. Is traffic flowing? Then merge as soon as it's safe.

So, tell me in the comments. Do you merge early, or late?