Twice on the same commute, I witnessed the same curious behavior.
When a double seat opened up completely, someone already sharing a seat with someone else would jump up, and without checking to see if any of the standing people were moving toward the seat (and in one case nearly running someone over in the process), scurry over and sit in the empty double seat as fast as they could.
I can understand the appeal of not having to share a seat, of course, but the hurry to do so while there are still people standing in the car inspires a moderately evil impulse… I always want to slide into the seat with them and spread out a little, just to see the looks on their faces.
This post appeared in its original form at DC Metblogs