I went to a lecture about this nearly 20years ago, my university's computer science dept worked on this stuff after a fire at a tube station in London in 1988.

It's surprisingly counter-intuitive how people move. For instance when they come out of a narrow corridor into a large space they stop - it's safer to put exits at the end of corridors. You also don't want to put them in the corners.
The original tests involved ants and plastic mazes

The most important conclusion was that people move with the air flow = toward clear air. This is what caused the most casualties in the tube fire, people went up the stairs - but because of a chimney effect so did the fire.