I have a creek dividing our property, and am trying to clear the land that is overgrown. I needed a bridge to go over the creek that would let me get the riding mower over there. I built it 12 feet long and 5 feet wide. Each end of the 2x6x12's are on concrete piers. I ran 2x4's across those, and put up a railing, mainly for looks. The only issue I had was not making the ramp long enough. On my first trip, the blade assembly on the mower got caught up. So I extended the ramp for a shallower angle.