Its surprising how different a bridge looks from the deck. One would hardly notice crossing a bridge over a river from the road. I guess a bridge always has two aspects, one from above the deck and another from below the deck.
For some reason, this bridge has two sidewalks although they don't continue onto the adjacent roadway. Maybe the sidewalk allowed the designer to use a vertical barrier rail instead of the New Jersey barrier used on US bridges. These barriers are shaped to push errant vehicles back onto the road.
The sidewalk and rail have expansion joints to allow each span to expand and contract. Note the end of the rail has black and white stripes and the sidewalk curb is painted yellow. Apparently the Mexican Highway Department uses paint rather than protective devices to prevent injuries to distracted drivers.
Mexico's Bridges: Puente Rio Armeria (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.