On the road it would be עוקפת. At least if you mean that both of them are going on the road, and the speaker takes over the man.
You can say "אני עוברת את החנות", meaning "I go past the shop". I guess you can also do it with a man, but it sounds funny, as if the man is some landmark...
Context where I'd expect עוברת את הגבר are maybe in grades, height, something like that.
Schneur, imagine a jealous husband:
“You stop and talk with that guy every day, don’t you?!”
“No, I just pass him by.”
“You flirt with him!”
“I pass the man! That’s it!”
It’s hard for people to imagine every context where an unusual sentence might make sense, so you have to trust Duolingo to give you short sentences which makes sense in a context you haven’t imagined.
The meaning would be clearer with a longer sentence such as “I pass the man every morning on the way to work”, but at this beginner level they’re doing you a favor with short sentences.