I also remember the kids in school who behaved similarly. Being in a school is like being in traffic, stuck with a bunch of people you didn't choose to spend your time with and you have no choice but to be there.
And we can't forget how perceptive kids are. They're "stuck in traffic" with the same cluster of people. They recognize trends and patterns. We, as adults, might wonder why they're blowing up over something that seems so small. But we haven't always seen everything that led to that conclusion. When you're driving and you recognize a driver that's aggressive and reckless, even a casual mistake looks like an intentional, aggressive move.
This is also an important thing for the kids to understand. People pick up on patterns. If you're regularly starting problems with others then when you genuinely make a mistake, you won't be given the benefit of the doubt. And it isn't limited to just the person you created a problem with. Every action you make is being watched. You cut somebody off, you're bothering more than just the person you cut off. And this affects how people think about you and treat you.
We can't help kids process through their problems without understanding the context. And really, it's tough to relate because there are so few places we go as adults that are like school for kids. Sitting in traffic always reminds me what my students go through on a daily basis... for 8 hours straight. Helps me remember to cut them some slack when they seem like they're on edge. It also helps me remember to look for the underlying patterns that lead to the interpersonal problems I see.