How do i make a object follow a bezier but still be affected by gravity?

I’m planning on trying to make one of those zipline cart ride things, but using regular physics on a track isn’t working. It keeps getting stuck and glitched.
So my question is how do i make a object follow a Bezier curve but still be affected by gravity? So it can rollback or not go up a hill and stuff. Basically like Theme Park Tycoon 2’s rollercoaster system actually.

I’m not sure if this is related at all, but maybe AlignPosition could help?