I tried to model the phenomenon I saw at the site in order to more accurately express its depth.
The horizontal red lines express the movement of cars on the bridge which casue the movement I have been mapping under the bridge.
The vectors I drew represent the rays of shadows which pass through the space in the bridge and leave traces of the motion that passed.
The vectors express the direction of the rays and the areas that they effect at a given time.
I connected all the vectors in order to express the entire area that was effected by the rays.
This is a section of the area that was created by the rays.
Layering the sections.