These studies are indeed serious. This sort of thing has been used for architecture and road traffic planning for several years, including planning major sports stadiums and concert halls. The key were advances in maths (around complexity theory I think) and computer power - I believe the first researchers were very surprised by their results and even more so when experiments with real crowds supported their findings. (One of the first was a study on traffic jams and speed limits, I think - it turned out that given whatever variables, there was an optimum speed for the highest traffic flow, and speeders held everyone else up.)