RE: Highway undercrossings
In the past, I had access to an area that had an underpass next to it. Deer densities were definitely high in that area.
Since this seems to be a very good funnel that doesn' t offer much in the way of set-ups, maybe you can " close off" the other access routes the deer are using with trees and other obstructions blocking their usual trails--even twine will work for a makeshift " fence." Leave ONLY the trails headed your way open.