I believe it was Andre Gide who said, "Hell is other people." I like that a lot. On the other hand, one must consider the flip side, "Heaven is other people," which Andre Gide did most emphatically not say.
Let's suppose there is a Hell, and let's stipulate that it's not a nice place. Dante made the lowest level of Hell a lake of ice, into which traitors were frozen.
Actually, Dante had a lot going for him. He realized that you can't just have one Hell. You've got to have several. One doesn't want to put a regular garden-variety adulterer in with biggies like Hitler and Saddam.
But I digress. The question is not where but why. And I'm going to take my clue from Gide. It's what we do to people, or rather, how we perceive ourselves in relation to other people. If you think that you are more important than a handicapped person, and deserve to park in their slot, then you are going to Hell. If you think that red lights are for other people, then you are going to Hell. If you think that you automatically belong at the front of a line, then you are going to Hell.
If you think that your waitress should ignore all the other customers, if you think that the person at the bank window has time to solve your addition problems, if you think that the store clerk should drop everyone else and help you decide between mauve and puce, if you think that it's important to shout into a cell phone in a restaurant, theater, or church, then you are most definitely going to hell.
I mean, how many of us commit really serious crimes? Among my acquaintance there are very few murderers, traitors, thieves, and the lot. It's the small things that are going to get us.