There has to be another way creating roads. Can anyone give me some suggestion?

This is what I am stuck on:


And I am using this GITHUB project:

What I was trying to do is build a surface for roads and I’m going nowhere constructing roads. Are there any other way of constructing roads?

I had an idea of and I have no idea implementing as I am current new to UE4 C++. My idea is importing meshes, have extrude, by having it extrude it creates another meshes, and what I would like to do is also be able to split that mesh into section to contour the road layouts on this project. The road layouts are colored green. How would you implement something like this on UE4?