So rail junctions are a nice simple way to pick between two destinations for incoming minecarts, however the challenge is making an easy way for the player to pick which direction they want to take as they approach the junction.
The simplest method is a button that they have to press while approaching the junction in the minecart:
Pressing the button causes the rider to switch onto the outbound track. Not pressing the button means they continue on the loop to the next junction. The problem here however is that the button is very hard to hit correctly while riding the rail at full speed.
What is an easier way for a player riding on a minecart to activate a junction so that they can take the alternate pathway? To be clear, the player should still have the option NOT to activate the junction and take the default path as well (as seen in the image above).