Crowding and personal space invasion on the train: Please don't make me sit in the middle

Mass transit users frequently experience crowding during their commutes. In this study of 139 urban passenger train commuters during rush hour, we found that the density of the train car was inconsequential for multiple indices (self-report, salivary cortisol, performance aftereffects) of stress whereas the immediate seating density proximate to the passenger significantly affected all three indices. When people had to sit close to other passengers, they experienced adverse reactions. These results are consistent with prior work indicating that individual spacing among persons that leads to personal space invasions is a more salient environmental condition than density per se. The findings also have implications for the design of mass transit vehicles.