Crowd Running Simulation

This animation was my first project with animated people and though not realistic by any means turned out pretty well. I was inspired by the police running in the Dark Knight Rises, but these people are running for no reason. I animated movements for 8 or so characters and then generated them with a particle system. Some of the arms overlap if you watch. I made four people running, 2 standing, and two tripping. I duplicated the running people and then modified the keyframes before adding them to a group. The particle system had the people running with their feet deep in the ground so I duplicated the emitter and moved it upwards. I tried to stick to wide shots for realism reasons. If I ever do another crowd project does anyone know if it is easier to duplicate every person multiple times, or is it easier to use a particle system? Here is the video.

Looks like a solid effort. Have you seen the addon for crowd simulation?