People not moving cars for alt side street cleaning?

We parked a car outside last night (80s/90s, closer to Central Park than to Riverside) and noticed that there was street cleaning in effect from 8:30 onward this AM, so went out to move the car this morning. Noticed that NO ONE else has moved their cars - the entire side of the street with cleaning is completely parked. Is this normal for the neighborhood? Obviously, not complaining if it is.... but are cars not ticketed that often up here? Does it have to do with the snow? Just want to understand what our options are. thanks!