The Tinguiririca Bridge is a railroad bridge (on the west side of Route 5 Sur in Chile). In this photo we are looking at the bridge between the barrier rails of the adjacent highway. A variety of lifelines including gas, water, railway, and highway often conveniently share the same right-of-way (at least until one of them starts having problems that impacts the others).
This is a through truss bridge and I believe it's a Pratt truss because the diagonal elements slope downward towards the middle of the bridge. It is a three span bridge with catenary elements to hold the electric line that powers the locomotive.
Chilean Bridges: Puente de Tinguiririca by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.