About Weaving and zip merging: who yields to whom, and the 300/50-metre rule: which statement is WRONG?
When weaving, exiting drivers should let merging drivers go first, because exiters are leaving the motorway anyway.
Already at about 300 metres before the narrowing you adjust your speed to the adjacent traffic; only at about 50 metres do you actually merge.
The agreement is that every driver on the through lane lets exactly ONE driver from the obstructed lane go first each time — not two or more in a row.
Use all available room up to the narrowing: adjust speed at 300 m, only actually merge at about 50 m.
Explanation
trap: direction of the priority rule reversed. Book p.153 - because mergers drive more slowly and have more room and overview, it is actually the reverse: mergers let the exiters go first