I am not sure. We boarded last, and it did not seem like there was a split lane.

There were at least 3 different priority board times (one for Premium class and really top tier, and then 2 other levels of priority boarding). Then the rest of the boarding was by rows.

A to E boards on door 2L, F to K boards on door 1L.

Honestly, with 400 people boarding in 15m, if you show up late to the gate, you are toast for O/H bins anyways.

From what I saw, everyone was present when boarding started. Only 1 pax showed up late, which delayed us a bit, but that is it.



Flight was at 19:30, we pushed back at 19:25, boarding started at 19:10.


Edit:

I think that my BP showed boarding at 19:00. The gate said boarding at 19:10. Everyone was ready at 19:10. The gates were clear. People were standing up waiting to be called, but the area close to the gate was free, and people stepped up when their "zone" was called.

The way it works is that there is an announcement that says "We will shortly begin boarding passengers with [insert ticket type (J/PE)]/[insert status type]." Then they call that zone, and a GA is in front of the tourniquets holding a laminated sign. Then everyone shows up at the gate (with the scanning system people get processed really fast).

Once the gate becomes empty (no more people in line for that "zone"), they call the next zone.

So, if AC was to do this, they would call Zone 1, everyone in Zone 1 shows up and scans their own BP and walks through. Once everyone has gone through that gate, they wait maybe 30 seconds or so, and then they call the next zone.

I can see why ANA is so organized with widebody boarding though. FUK-HND is all widebodies, by the hour (sometimes every 30m), and most flights leave full. So no time to fromage around.