Efficient packing in an elevator

What is the most efficient method of packing in an elevator? More specifically, lets say an apartment building has N(=36) stories and you stay on floor n(=29). When you enter an empty elevator, where do you stand?

What are some factors to consider?

1) Is there anyone else entering after you? If so, you shouldn't block the door

2) How far in should you move? You'd have to walk that distance out again.

3) You'd want some personal space between you and the other person. This space should be approximately equal.

4) As the elevator empties, you'd want to maintain an approimately equal amount of personal space.

5) Clearly, the elevator patterns of latter passengers should influence your decision.

6) And what is the elevator is not empty? Has your elevator patterns influenced those who were in the elevator?


Clearly, I have way too much free time to be thinking about such stuff. Well, its just a distraction so that I don't think about other stuff.