Avoiding COVID transmission in the elevators of tall residential buildings, seems to be impossible.
Clearly, stay-at-home orders have very limited effect since the residents are already at home. Elevator cabs are very confined spaces, and it takes time for people to enter and exit.
Suppose a ten-story apartment building restricts elevator capacity to one person at a time, it takes an average of 30 seconds for a person to get on or off, and the average travel time is 60 seconds. Under these unrealistically optimistic assumptions, the elevator can transport just 30 people in an hour.
I don’t see how social distancing can work under these circumstances.