When having minecarts move along tracks, it is possible to get them to interfere with each other by having two minecarts attach to adjacent ramped powered rails. I am also keeping the two minecarts in place before letting them both roll forward through the use of open trapdoors one block above and forward the ramped rails. This should expectedly help keep their velocity at 0 and essentially reset any interference on the turn, however it can be heard that minecart movement sounds are still played while the two adjacent minecarts are supposedly still. Letting the two adjacent minecarts roll forward results in one launching with more velocity than the other, despite the tracks being the same.