There is nothing worse than turning down a long hallway at the office to find another person you know walking in your direction, and knowing you are going to pass them.
At what point do you acknowledge them? As soon as you see them, or only when you're close enough to say hi?
If you nod or say something too early, then you have to maintain the connection until you pass each other, which can be long, or look away again, which means you will be passing without further acknowledgement. Both are super awkward. And maintaining eye contact that long can lead to, um, misunderstandings.
If you wait until they are close, you have to do something in the meantime to NOT acknowledge them. Pointedly looking away makes it obvious that you are trying to avoid eye contact, so you have to do something like shuffle papers or adjust a button, or pretend to be looking at something really interesting on the wall beyond them.
And if you go with the latter, at what point DO you look up? Just as they pass, or a little bit before? If they're not already looking at you, do you keep staring until they do? Because if you don't make eye contact at exactly the same time, it might appear that you've been ogling them. But if you look away, you might miss THEIR eye contact. Then you might start to hear on the office grapevine about what a rude person you are, with all that high and mighty ignoring that you do.
It's always a pleasure to find that the person walking towards you is someone you don't know, because then you can just ignore them until they pass, only giving a nice little nod or smile if you want to. OR that the person is someone you DO know and you actually have something to say to them. But that hardly ever happens to me.
I have to walk around a lot, so I get caught in a hallway walk-by at least once a day. And I'm still no better at handling it than I was six years ago. I've been know to blurt out strange things when I couldn't handle the pressure, and to blush bright red when eye contact was made too soon and I didn't know what to do while the gap slowly closed.
Today was my low point. As soon as I saw her turn the corner in my direction, I pretended I'd forgotten something, turned around, and walked back to my desk. She is an early eye contact maker and maintainer, and a loud voice inside my head started yelling, AVOID AVOID.