This set up worked prior to 0.15.0.
I place a tripwire over a minecart track to detect when a player-occupied minecart passes through it in order to switch track direction.
Tutorial by Cr3wProductionz that I am using: https://www.youtube.com/watch?v=xiDduDn3LZI or
https://www.youtube.com/watch?v=cvc0df1wcP4 (shorter video)
This works when I WALK through the tripwire, but not when I RIDE a minecart through it.
Still not fixed as of 0.15.6
I can confirm that the tripwire isn't tripped by any player or mob riding the cart - Win 10 on 0.15.0