n34s
Thanks for the advice. In fact, there are many dangerous tracks in Abruzzo and with any kind of surface. This is no exception, on the contrary, it easily represents almost all of them 😅.
But one thing doesn't add up: if you say you've been there and done it to the end and even turned back then why when you indicated the presence of the natural disaster did you focus only on the ESRI World Imagery? 
I doubt that you've been there recently or you would've been able to draw the blank area where you assume that there's been a natural disaster. Or the disaster didn't involve the path and therefore, not being afflicted by it, what can be seen from the aerial images is not easily discernible in person.

The thing that also leaves me even more confused is that cyclists can face such a battered track with light clothing (see photos of participants) not at all suitable for crossing the dense vegetation, let alone passing through the thorny branches. I did it for a few meters and luckily I came out with only a small scratch.
If it were as you say that the race is held every year (like the Festa dei Banderesi) all the weeds would be pruned and the thorny branches removed to ensure at least a minimum safety standard for riders.