The sharp-eyed among you might catch the names of the films playing at the theater as the trolley goes hurtling past: Strangers on a Train and Bend it Like Bentham.
The first joke is pretty obvious. The second is a bit more obscure. Jeremy Bentham—John Stuart Mill's godfather—is best remembered today as the founder of the modern moral theory of utilitarianism—which, of course, the trolley problem is meant to problematize.