What? That one I made does stop at the same place.. and then will leave at a random time, between whatever min and max you give!
If at any point you want to stop the timer which is telling it to go, then toggle the timer off.
If you want it to be rideable, you will either need to make it slow right down, or add a lot of path_tracks for it to go around smoothly. Otherwise, players won't really need to be riding it most of the time so I wouldn't worry.