And if so, what if someone rolls into the john in a wheelchair just as you're stepping into the stall?
What is the proper thing to do? Anyone?
Just wait. Some busybody will make a law against using it without permission.
Of course, ENFORCING this law would be a big mess (in more ways than one *yuk*).
The proper thing is to use it and when you have finished your business there move out.
Those stalls are just handicap accessible, not specially set aside for handicapped people. You can use them.