1 Mike: Mirkwood. It’s a real road. It’s just the name that’s made up.
1 Hopper: What’s its real name?
2 Mike: I don’t know. It’s where Cornwallis and Kerley meet.
3 Hopper: You know the names of two intersecting roads, but not this other one? That seems unlikely for a bunch of smart-alec kids.
4 Lucas: Why do you think we call it Mirkwood?!

I thought it was a bit weird in Stranger Things that kids wouldn't know the name of a road that they regularly take to travel between their various houses.

The other odd thing is that they chose to name the road after a fictional forest, rather than, you know... a road.

Although admittedly Tolkien didn't exactly give them much to work with. The road that goes through Mirkwood is named, creatively, The Great East Road, with specifically the part of it through Mirkwood being named The Old Forest Road.

Obviously he should have called it Mirkroad.