Pick the correct way to call a lift:
Option 1:
Press both up and down buttons, wait for a lift to arrive and if it is going in the incorrect direction to suit your wish, grumble that the lifts in this place are useless.
Option 2:
Press only the direction you wish to travel in. Get in the lift. Get out at your destination.
Correct way to design a lift:
1) The way normal lifts work. Call lift, get in, press floor number for destination of choice.
2) Have a stupid destination pad OUTside the vestibule for the lift which visually shows which lift will take you to your floor. Hope the user has no visual impairment or short term memory impairment (e.g 10% of people have these) as the user has to remember which lift while shoving through crowds and hope they get to their lift in time before it gets reallocated. It's a HORRID feeling not having any control of where the lift goes from inside the damned lift.
I have minimal memory issues and I can only remember which lift I am allocated by holding the American Fingerspelling Alphabet letter for the correct lift on my right hand as I shove through the crowds. My blind colleague can't use the building as there are no receptionists as per design spec.
It might be more efficient, but it's a fucking horrible user interface which usually makes me swear every time I use it. The least they could do it put the pre-request floor destination thing in the lift vestibule! Although if there is NO damned floor 0 then don't have a fucking zero button on the sodding thingers.
hate hate hate...