Hallway Awkwardness

You know exactly what I’m talking about: when you see someone you know in the hallway and you don’t know what to do.
The first time you see someone in a day, it’s always cool to say “Hi”, or mention their name, depending on how close they are. But then you’re also struck with the fact that they may not want to say “Hi” back, and then you feel like a complete idiot left hanging. So then you wait unless the last second and then try and cheat out the most polite thing in the shortest amount of time.
And the opposite is the long hallway when they come from the opposite direction. Who knows what the proper addressing distance is? Do you scream when you see them, or do you wait unless they’re right beside you? And if the latter, what’s the proper time to make eye-contact? Do you creepily stare at them down the entire hallways, or do you fake like you’re looking at the ground, only to be “surprised” when they’re right beside you?
And when you’re walking parallel to someone (in front or behind), there’s the trouble of figuring out whether you should catch up or slow down or what. If it’s a close buddy, then sure, make your move. Unless you just chatted all last period, and you know there’s nothing to talk about. So you might try to speed up/slow down when you see them. Unfortunately, if they see you as well, then it just gets really awkward. You never want to deliberately ignore them, but you know that if you move to intercept, nothing is going to come of it, because the failed-conversation is much more awkward than the trailing-buddy method.
What about the double intercept, when, say, you’re talking to someone, and then they’re boy/girlfriend walks up. You do the tango for a moment, trying to figure out the proper walking order, but then just end up pissing off everyone else as you block the hallway. And then it’d be impolite to just walk away from them, so you stick with the couple, awkwardly listening-but-trying-not-to-listen to their loving noises. My usual method involves pulling away or stealing the male member, with something like, “he’s mine!” (has to be the guy because then it’s just a laugh; if I go for the girl, I get knuckles in my face), in which a minor struggle ensues long enough to reach the destination without problem.
But that’s not the worst double-intercept. Let’s say you have to talk to someone, but they’re already talking to one of their buddies you don’t really know. You really quickly throw in your comment (or you take a long time with your comment, making it really awkward for their buddy), and then you know that you’re stuck with them. You can’t escape by grabbing one of them, because that… just doesn’t work. Instead, you try to pretend like you know their buddy better than you do and make smalltalk, or you end up in some really awkward conversation where someone is left out.
And then there’s the fact that you can’t have more than 3 ppl in a walking party without being a jerk to others (and blocking the hallway). Then you end up in a little cluster of buddies, where you have to look behind you and stuff to maintain smalltalk. But you know that usually, you’ll pair off into a little train, and then you’ll talk to your partner. But you’re in a group, and you can’t just reject the ppl behind you (and they can’t just ignore you). So you have to bridge the conversation again, but it doesn’t work because it’s just awkward to try.
And then there’s holding doors. Do you say, “thanks buddy!!!”, or is the slight murmur okay? Do you move for the door to relieve them of the duty, or do you allow them to suffer the pressure being applied to them by the door? But it’s worse for guys because when girls hold doors, you feel obligated to take over (even if chivalry is dead). But trading off doorholders is awkward, and then you just jam up traffic and you do the ol’ switch-er-roo.
And I’m sure it gets even more awkward when it’s someone you like-like. You know you have to be wvr your tactic is, but you can’t come on too strong, or risk scaring them off. But if you openly ignore them, then you’ll later wonder if they actually wanted to talk to you, and, in the end, you were just a jerk to them. And what’s the proper greeting for someone like that?
I know it isn’t just me.
Why is walking such a huge social problem?