There are some variations in different translations of what they are riding in the story but the best interpretations seems to be these small compact trams that are found in populous cities. The picture here is a tram from around the 1940s, China which should be more or less what the tram in the city. It’s small and it’s compact. When it’s moving, people hustling on and off, there is no need to talk to or communicate with anyone, everyone is in close quarters yet ignoring each other, but when on lock down there is no kind of escape. There aren’t any other compartments to escape to there aren’t any bathrooms for a bit of alone time. It’s a small rickety tram and when it stops, you are suddenly forced to look at the people in your surroundings, people feel more obligated to actually talk to someone, to make a break in the silence. Your stay in the tram becomes more permanent, something more indefinite. You don’t have a clear idea how long you are going to be inside the sad little thing and there is only so much you can do to keep yourself busy. No one wants to talk to other people on public transportation but it’s always an amusing day dream; what are other people thinking about on their commute. Once that train stops, you are put in limbo, just as when the subway decides to stop in the stations, or worse, in between stops and that is when people don’t know what to do with themselves and that is when their minds wander and want human interaction so that they kknow that they are not alone in that weird pocket of time.