Simply put, they are all wrong. A bottleneck is a bottleneck and there is no fairy dust magic queueing technique that works better than another. At best, some techniques might have a behavioral advantage...but I stress again, they are all inconsequential. We are talking tens of seconds of time savings at best.
Ignoring early exits, at steady state, the only thing that really matters is flow _after_ the merge - that's what determines the rate at which traffic passes the restriction.
However, it's a simple matter of utilization, if everyone waited properly in line, traffic would seize up in Beijing as many intersections would become blocked by single lines of cars next to empty unused lanes.
We are talking about saving minutes, 10s of minutes, or even days [1]. Funny how Americans haven't seen real traffic before and think they know the right global solutions.
[1] http://www.npr.org/blogs/thetwo-way/2010/08/23/129376194/tra...
1) It's a more effective use of the roadway. Why have 1 lane of traffic backed up for 2 miles when you can have 2 lanes of traffic backed up for 1 mile? 2) It's equitable. Everyone moves at the same speed, there's no way to game the system for personal advantage.
The problem is the bottleneck point, where people are obligated to move into one lane. This is what causes delay - the faster you can get cars moving through the bottleneck point, the less delays there will be behind. So it doesn't matter so much where the cars behind are positioned to wait.
Zipper merge likely causes more delay - in practice - as there has to be a late negotiation over whose 'turn' it is to merge. If this negotiation is planned earlier, it doesn't need to have such an effect (in fact, I imagine it could eliminate all the delay) at the bottleneck point.
| _ _ _
| _ _ _
| _ _ _ _ _ _