The superstructure that carries foot (and bicycle) traffic on the Sundial Bridge is built from triangular segments with a central spoke, similar to the vertebrae that supports human beings. Calatrava's work is often inspired by the human figure or by human structural elements.
In this photo we can see the unpainted tower behind the assembled superstructure with additional superstructure elements in the foreground. Cable stays are in rolled-up coils beside them. All that remains to do is put the remaining superstructure elements together and hang them from the tower.
Cable-Stayed Bridges - Sundial Bridge (4) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.