A traditional British school classroom often had high window-sills—to prevent the seated pupils from being distracted by more exciting events outside, or indeed staring out of the window.
‘Redesigned to face contemporary urban realities, this bench comes standard with a centre arm to discourage overnight stays in its comfortable embrace’—from Belson
Oxford bus stop
This is only one step away from Jeremy Bentham’s Panopticon  and Michel Foucault’s argument (in Discipline and Punish ) that by embedding punishment systems in architecture and institutions (e.g. prisons) rather than meting out direct retribution publicly (e.g. public execution or floggings), the likelihood of adverse public reaction to the punishment is greatly reduced. In the park bench example, a public confrontation between police and a person sleeping on the bench (with possible sympathy from bystanders) can be avoided entirely by preventing anyone sleeping on the bench in the first place (using the architecture to control). Not for nothing are speed humps commonly known as ‘sleeping policemen’ in the UK.
(h/t Savage Minds)