On one of the highest paved roads in Europe with fixed-gear bicycle (footage)

[Dan D]

Yes indeed.
It is a technique that does not work on freewheel: cyclist locks the rear wheel and then skids to slow down. „Such a move is initiated by unweighting the rear wheel while in motion by shifting the rider's weight slightly forward and pulling up on the pedals using. The rider then stops turning the cranks, thus stopping the drivetrain and rear wheel, while applying body weight in opposition to the rotation of the cranks. This causes the rear wheel to skid, and slow the bike. The skid can be held until the bicycle stops or until the rider desires to continue pedalling again at a slower speed.

A wet surface further reduces the effectiveness of this method.“

(„Fixed-gear bicycles for the road“ by Sheldon „Coasting is bad for you“ Brown)