We have lots of varying slopes so drainage is always the first consideration for anything we do. Running roads through existing, natural drainage is just making more work for yourself.
We came up with the idea of a bridge made from old power poles and some lumber. I dig the clackity clack sound when crossing a bridge so we decided to build using dowel instead of bolts or screws.
Again, I underestimated how much work the dowel idea would be but it turned out great and still goes clackity clack today.