This is a photo from two years ago, i stood there for a good minute wondering how the hell and why this weird cycle path was there. It is in southern France, on the climb to Col d'Ecre, bit north of Nice.
Now that i have found this, i kinda want to go back and collect the cols, haha.
Seems like quite some people snap a pic of themselves there. Not sure if it's the best way to spend money on cycling infrastructure, but i think it's a fun little project.
Maybe i was exaggerating when i said i fully understand it. There is this Cols Connectes thing from the department alpes maritimes where climbing a col is being gamified, to collect the cols and take the times, upload photos. And this infra is part of it, taking a photo. Maybe there is are also stations like this at the bottom and top, for the timing, but i did not see them if they were there. But i also rode some of the other cols and did not notice anything like it either, but apparently it's there.
I knew this infra was somehow part of "cols connetces", but did not really understand what it did, i had asked it before in the french cycling subreddit.
A pullout area to allow backed up vehicles to pass?
It's strange that it's on the downhill side and not the uphill, though!
Other guesses: Brake check area (stop and let brakes cool...); U-turn area as we sometimes see for the 'j-turn' configuration; The pullout is for uphill cyclists but they have to make a u-turn to use it.