A third option .. and possibly a fourth
The traditional runaway trolley-bus dilemma has it that you you see a runaway trolley-bus approaching, whilst standing near the points. You have the option of diverting it to hit one or other of two groups of people. To make it interesting, one group is usually more "deserving" than the other - possibly a choice between a group of school children or a load of drunks who've fallen asleep on the tracks.
There is, however, a third option. By throwing yourself into the path of the trolley-bus you could derail it, or at least slow it down, thus saving both groups. This option has the questionable advantage that you won't have to live with the consequences of your choice (or with anything else, come to that!). I suppose the motoring equivalent of that is where you could avoid a collision with both oncoming vehicles by steering into a concrete wall, or over a cliff. Your choice in that situation says a lot about the sort of person you are.
There is another variant of the dilemma which offers a fourth option. Here, you're still standing near the points watching the runaway trolley-bus. But this time you're a policeman who's just apprehended someone suspected (but not convicted) of committing a particularly nasty crime. You thus have the option of throwing him in front of the trolley-bus instead of yourself. (I can't think of a motoring equivalent for that)