Over ten years ago, I posed, and answered, The Toilet Paper Question (read it now, if you aren’t familiar with it).

Yesterday, while on vacation, I noticed an interesting design that
implements the solution:

The covered roll has a panel labeled “SLIDE DOOR OVER WHEN EMPTY” and it has a mechanism that makes it difficult to slide when the other roll
isn’t empty.

Now, there will be an entire roll available for use when an empty one is ready to be replaced; minimizing the chance that they will both be empty before maintenance workers can replace an empty roll.

This is a much better solution than waiting for most people to adopt this reasonable practice themselves.