[justfane]

It doesn't have enough momentum to fully go up the last 'slope' so it rolls back down with the momentum to get back to the starting position... I believe that's what i gathered from the end of the page.

[aidos]

At least it might have if that pesky physics hadn't gotten in the way, again.

They probably just pull it up with a rope or something.

[aetherson]

They just reverse the arrow of entropy real quick to get it back to its starting direction.

Remember to reengage physics before starting the ride with the next rider.