The premise behind these simulations is that giving directions to crowds will improve flow of people.
It's a mighty big assumption that the folks in the crowds would follow a signal to "slow down". Between the culture in general (ever see a tidy British style queue in the middle east?), and the general human dynamics of large crowds of people, I don't have much hope of this being a success...
...The activity of the crowd is determined by a very weak signal, if you can give them a strong signal instead they'll probably follow it.
Imagine you have a bunch of giant LED billboards overhead showing everyone in the crowd "SLOW DOWN" or "STOP" or "TURN RIGHT AT 42nd STREET".
A baffle sends a strong signal that is impossible to ignore. Cylindrical pillars seem to be among the most efficient at transmitting this signal in the right directions through the crowd so that it slows them in time to prevent crush injuries without panicking anyone into a stampede. Forget cultural stereotypes and objective cultural differences, at this scale all Muslims, Christians, Soccer fans, British Royals, bipeds, quadrapeds... behave as particles in a non-Newtonian fluid. If these particles encounter a barrier faster than the signal from the barrier can propagate against the flow of the fluid, you get a shock-wave not unlike a sonic boom.