[2006alum]

According to this, when the CA seatbelt law was passed in 1986 it was a "secondary enforcement" law, which meant that an officer could cite a motorist for a belt use violation if and only if the officer had already stopped the vehicle for some other reason. Only in 1993 did it become a "primary enforcement" law. The linked study observed that seat belt use increased from 58 percent to 76 percent soon thereafter. 

So even the seatbelt example isn't analogous, because presumably those calling for citations for non-mask-wearing want this to be a "primary enforcement" rule.  

Incidentally, at least in my SF neighborhood, mask-wearing is already well above 58% inside public accommodations and in crowded outdoor settings - I'd guess closer to 80% apart from those actively exercising. Given all this, I'm skeptical the proposed rule would create more benefit than harm.

[2006alum]

According to this, when the CA seatbelt law was passed in 1986 it was a "secondary enforcement" law, which meant that an officer could cite a motorist for a belt use violation if and only if the officer had already stopped the vehicle for some other reason. Only in 1993 did it become a "primary enforcement" law. The linked study observed that seat belt use increased from 58 percent to 76 percent soon thereafter. 

So even the seatbelt example isn't analogous, because presumably those calling for citations for non-mask-wearing want this to be a "primary enforcement" rule.  

Incidentally, at least in my SF neighborhood, mask-wearing is already well above 58% inside public accommodations and in crowded outdoor settings - I'd guess closer to 80% apart from those actively exercising. Given all this, I'm skeptical the proposed rule would create more benefit than harm.