I see these every time a bicycle path intersects with any kind of car or train infrastructure. It just seems really patronizing, as if we’re not capable of slowing down without getting off the bike; it also shifts responsibility onto the cyclists if there is a crash based on something arbitrary (mounted vs dismounted).
IDK I think the “bike lanes” that are actually just fucking gutters that have never been cleaned or maintained is a more infuriating sign: Paint doesn’t really protect people but places that put up these “bike lanes” give themselves a big pat on the back, put up bullshit “bike friendly” signs, and then DGAF when a cyclist is killed or injured by another shitty driver who will barely be held accountable, if at all.