[actionfromafar]

It's a coordination problem - taken in isolation, it's not irrational. If only you refrain from doing it, and 37 other people do, you will still have to wait for the next train, and the train in front of you will be almost as late anyways.

[derdi]

The wait for the next train is one factor, the overcrowding is another one. I'm usually not in such a hurry that a minute's wait would make a difference. But the next train is very likely to be much less crowded and much more comfortable to ride on. From my point of view the decision is clear, in isolation, just from my own selfish point of view. And I think many others are making a choice that makes them unhappy. (Train systems differ, the one where I live has sufficient capacity that you rarely get two overcrowded ones back to back. I know there are places where this does not apply.)

[sokoloff]

> a minute's wait

Is your subway system running trains every 1-2 minutes (30-60 trains per hour)? Mine has trains at 5-8 minute spacing at peak times and 8-12 minutes off-peak.

[derdi]

No, it's running at 3-5 minutes at peak times. But bunching significantly shortens the interval between the delayed, overcrowded train and the empty one right behind it.