Hello. I agree that there are mapped highways which looks like they are barely capable to carry (4x4) cars.
However, The most traces went through desert landscapes where there is enough room for cars. See the mass of traces parallel to each other. We cannot see if these traces are caused by car, people by foot, livestock or wild animals.
I find it difficult as well.
There is no other option than those listed in the wiki. Most common here highway=unclassified. No need to map paths, however, when only paths connects settlements (In these areas most common) I tend to map them as path.
You know how to measure the width of a trace in ID?
Additionally, a tag can be added about the qualify a highway, however that option cannot be added by mappers like us (satellite imagery don't show so much)
Best regards