My scenario. Letting my neighbor build a lower water bridge on the back side of my land so he and his neighbor won't kill eachother. He purchased the materials he found through craigslist. Found out there is no engineers involved. He didn't pull permits, didn't like the engineers price. Total violation of agreement. Took it upon himself to make it. He put poles in the ground didn't concrete them. The bottom of the bridge is made of railroad iron, and the top is a a steel cattle guard, welded together. Is this safe for someone to drive on with a car, truck delivery trucks, or truck and trailer filled with heavy wood logs?