Originally Posted by
StuckInYYZ
Why not do what some of the asian airlines do? Before boarding starts, verify and herd each zone into orderly groups and then start the boarding process?
YYC sometimes does this - for narrowbodies flying out of the C gates at least. They make sure everyone in the Z1/Z2 lines is indeed in the right lane. If they do this, they'll usually also size carry ons. Makes for the best boarding experiences by a mile.