overcrowding

noun

The situation where a space holds more occupants than it can comfortably accommodate.
“[…] there are sublettings, overcrowdings of lands, clearances, and emigrations going on; and want of employment, with consequent destitution and wretchedness is the complaint of the majority of the inhabitants.”
“An extra rush-hour train has eased overcrowding of the former 5.39 p.m. to Salisbury; this now leaves at 5.43 and an additional electric service to Alton departs at 5.39 p.m.”