Wow! Amazing work, heyguy!
Here's a modified example file.
Player character no longer travels off screen, and it disembarks once the spline path travel ends.
This is how I have fixed the issue
1. I found obj_ziplineSpline had a bullet behavior enabled. I tried disabling the bullet behavior, and it stopped traveling to the right after reaching the last spline path.
2. I unpinned both Player and Playerbox after waiting for 5 seconds and re-pinned Player to Playerbox.
Again, amazing job, heyguy!
This is so far the best zip line,roller coaster, barrel and path finding move example I've ever seen. Great job!!