When traffic is merging, what is a good rule to follow?

When traffic is merging, what is a good rule to follow?undefined
The larger vehicle has right of way
Merge like a zip (let one vehicle in then go)
The smaller vehicle has right of way
Speed up to make more room behind you

In many places in New Zealand, there are signs indicating "Merge like a Zip." This means that vehicles from the left and right should alternate and merge into one lane in a fair and orderly manner.