I have downloaded a scientific article about the legend of Devil Bridge at Google scholar.
You can read the article by Dr. Carme Oriol from the university Rovira i Virgili here.
Legend explains that a grandmother had to cross the river every day to fetch water from the source on the other bank. One morning, when she was about to cross the river, the Devil appeared to her ready to negotiate with her. He told him that he would build him a bridge so that it would be safer to cross the river, that in one night he would have it, but in return he asked the soul of the first to cross that bridge. The grandmother accepted the deal. The devil was working all night and as soon as it was day the bridge was already there. The Devil, hidden behind the arch of the bridge, on the other shore, waited for the grandmother to arrive, so that she would cross the bridge in search of the water and thus be able to keep her soul. But when the old lady reached the bridge, she let a black cat pass And so it is, as from that day on, the old woman and everyone else can cross the bridge without fear while the Devil looks at us, helplessly, next to the soul of a cat.
There are twenty seven versions in Catalonia of the topic of the Devil building a bridge in one night in exchange for a soul of a victim
Inside and outside Europe this theme is widespread in the tradition of many countries arround the world
Here's how you can see images from Devil Bridge legends from different countries:
