It's always better to gain a full understanding of the system when trying to make important decisions.
The trolley has two sets of wheels, leading and trailing, both of which must remain on the same set of tracks.
The switch is designed to enable the trolley to change course, moving from one set of tracks to the other.
Throwing the switch after the leading set has passed, but before the trailing set has reached the switch points will cause the two sets to attempt travel on separate tracks. The trolley will derail, rapidly coming to a halt. If the trolley is moving slowly enough to permit this action, nobody dies.
Source: former brakeman (one of the people responsible for throwing switches), section hand (one of the people responsible for installing switches), and railroad welder (one of the people responsible for field repairs of switches).
Yes, or come to a halt. You'd be surprised at how little it takes to reduce the already low friction to nothing. A bit of blood and a bit of resistance will bring it to a halt pretty quickly.
Thanks. This is the first time I've seen a jokey enough presentation to feel comfortable in treating it as a hypothetical reality rather than a moral/ethical exercise.
OR... if you can keep the wheels spinning really fast, you could "drift" the trolly, keeping a set of wheels on each track and kill everyone on both tracks into infinity.