Rioni

run the line. the lamps know where trains go.

run three lanes, swipe and jump, and read the switch lamps to know where each train will be

A train can't steer; its flanged wheels only follow the rails, and a switch ahead is set before it arrives. Read the switch lamps and signals and you know where a train will be before it gets there.

Concepts: constraints, timing, decision-theory.

An interactive you play with one thumb, on Wundr.