Creating minecart terminal stations are simple, but building minecart substations are more challenging. When a minecart is stopped either by running out of velocity or through a powered redstone brake, how can the cart be restarted?
There are obvious solutions to this such as set a solid block behind the cart and power the powered redstone rail, but this doesn't work if the cart is in the middle of a track. You can also put the minecart on a slope with a powered redstone brake and apply power, but this requires the cart to sit on a slope - which is awkward for a player to get into and out of.
So on a flat surface in the middle of a track, how do you get a minecart moving again?