For about twenty years I lined up on one platform after another and another-n'-another-n'-another, and the lines were always three people across. I remember hearing recorded announcements early on at some stations asking people to line up three across, and it occurred to me that it hadn't always been that way, hence the announcement. After that, though, I don't remember hearing that announcement. Either it was one of those things that is always in the background, so you just automatically tune it out, or they stopped making the announcements since everyone was dutifully lining up three across?
The only problem with standing three across, is that when the train comes, and the three-across line has to split to let people off the train, that middle row of people have to get in one or the other new line on the right or left of the opening doors, so the process ends up interfering with equal access to the train (on some lines, at some stations, the first people in can actually - gasp!- sit down!!) - this doesn't, on the other hand, interfere whatsoever when people are getting onto an empty train at the first station.
Jump through the years from 1984 to around 2005 or so, and one day I saw two people standing at one of the door marks (where the doors will be is usually marked on the platform, and the train operators pride themselves on stopping at precisely the same spot at the station every time), so I walked up and parked my standing bipedal form next to them, forming the third person. They looked over at me and I felt disapproval/irritation radio waves... "What?...." I thought, as I assessed the situation.... Reconfirming that I was the third person; not the fourth or fifth, I looked off into the distance and broadcast anti-disapproval waves and thought "Hey! I'm not being pushy! I'm just doing the regular thing! What's with you?" (Naturally no words were exchanged.)
Since then, I've seen people standing in pairs more and more until it's gotten to the point lately, that it almost seems official to stand two across. Equal access to the inside, etc. is great, but what's not great is when it's overcrowded (like every bloody day on a couple of the trains I line up for), and then you have a handful of people leisurely standing at the front edge of the platform, and - by the time the train is about to arrive - a huge mob of people unable to be in any kind of line at all at the back, and in danger of dropping off the edge of the other side of the platform, which becomes a real mess when a second train arrives on that side. Adding to the fun, there are actually people trying to walk along the platform (which they must - lest there be disaster at the junction of the stairs and the platform), and they have to physically force themselves through the mob.
Then - earlier in the evening, as I'm waiting for a train in Shinjuku, I notice the recorded announcement is asking people to line up three across.... Either it's new or I've been missing it all these years... I think it's new. What I'm wondering now is whether the urge to line up in pairs instead of triangles is a natural phenomenon?
Lyle (Hiroshi) Saxon