Philippa Foot's Trolley Problem

Philippa Foot, 1920-2010

Philippa Ruth Foot was an English moral philosopher. She died in 2010 at the age of ninety. Foot's original formulation of the problem ran as follows:

A  trolley, that's to say, in English English, a tram, is running out of control down a track. In its path are five people who have been tied to the track by a mad philosopher.

Fortunately, you could flip a switch, which will lead the trolley down a different track to safety. Unfortunately, there is a single person tied to that track. Should you flip the switch or do nothing?

How would you respond to this situation? How do you think one ought to respond in this situation? 

These trolleys or trams are Viennese!