Trolleyology?

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In this month's SciAm there is an article titled "The Wisdom of Psychopaths". Within that article is a blurb titled "Trolleyology" about a "conundrum first proposed by the late Philippa Foot:"

A railway trolley is hurtling down a track. In its path are five people trapped on the line and cannot escape. Fortunately, you can flip a switch that will divert the trolley down a fork in the track away from the five people- but at a price. There is another person trapped down that fork, and the trolley will kill him or her instead. Should you hit the switch.
 

I would have to make a decision as to whether or not the 5 were worth saving. So they may not have a chance. I would definitely save one good person and let five rotten bastards die. If only it were that easy. However the point is the one life you save could be greater than the other 5 combined.

There is a "variation proposed by philosopher Judith Jarvis Thomson:"

As before the railway trolley is speeding out of control down a track toward five people. But this time you are standing behind a very large stranger on a footbridge above the tracks. The only way to save the five people is to heave the stranger over. He will fall to a certain death. But his considerable girth will block the trolley, saving five lives. Question: Should you push him?
 

Most likely, but it still all depends on the five. But there is bound to be a rail and if I have to lift the guy then it ain't worth the effort, nor the risk of going over with him. And if there wasn't a rail I wouldn't be up there with some fat stranger who could push me into the pathway just to kill six people. A footbridge, over a railroad track, that doesn't have rails/ or a fence?

Now a subway platform, that's a different story.