Part of an event called Sternfahrt where cyclists protest for policy changes by taking over the city on 20 routes covering 2000 km of public roads.
some infos in german: https://berlin.adfc.de/pressemitteilung/adfc-sternfahrt-medienkit
translation to english: https://berlin-adfc-de.translate.goog/pressemitteilung/adfc-sternfahrt-medienkit?_x_tr_sl=de&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=wapp
@daddy32 yes, fahren means to ride any sort of vehicle.
Any kind of vehicle except for heavier than air aeronautical ones. Then it is “fliegen”. With lighter than air aeronautics it surprisingly still is “fahren”.