Flow direction: Unidirectional

Boundary conditions: Periodical (boys` school) and open (subway stations)

Places of research:

• British boys` school (experimental)
• London subway stations (field study)

Data collection:

• Boys´school: A circular passageway 4 ft 3 in. (1,3 m) wide and 30 ft (9,2 m) internal diameter was formed. Up to 200 boys were gradually fed into the ring. Speed measurements were made at different concentrations for several passege widths.
• London subway: Two observers with stop-watches stood at a measured distance apart. At a signal both observers started their stop-watches. The upstream observer immediately joined the stream of passengers and walked with them until he reached the second observer, when he stopped his stop-watch. In the meantime the other observer counted all the passengers that passed him between the time of starting the stop-watches and the first observer reaching him. In this way the total number of passengers originally in a measured area was obtained (hence the concentration), and also the time of the movement (hence the speed).