Strategically Placed Obstacle Near an Exit Can Speed Evacuations(scientificamerican.com)
scientificamerican.com
Strategically Placed Obstacle Near an Exit Can Speed Evacuations
http://www.scientificamerican.com/article.cfm?id=obstacle-exit-pedestrian
1 comments
See also
http://news.ycombinator.com/item?id=795329
where there is significant discussion.