I wonder how many days and how many tons of dynamite were require to remove all of that rock. It must have been quite a challenge to turn this rugged landscape into a well-graded highway.
Too often, we think of our bridges as something separate or more important than the roadway or railway that are the main purpose of all the money, effort, and occasional loss of life that are required to improve the lives of people.
I think roads are essentially benign. Clean drinking water requires roads for water trucks, drilling rigs, steel pipe, pumps, etc. The right-of-way along a road carries waterlines, electric lines, communication lines, etc. However, I agree with Norrin who mentioned that highways without sidewalks are too dangerous for people traveling by bike or on foot. Perhaps a good transportation system includes a mix of footpaths, horsepaths, bike paths, roads, and rails so that no one has to risk their life when they chose to travel.
Mexico's Bridges: Puente Atenquique I (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.