YMMV of course, but speaking for myself - if I have to take a cable car, I will position myself in the middle so I can't see out as well and clutch onto the post. It would be unlikely you'd get me near the railing of the observation deck, but if I really, really wanted to, again, white knuckle clutching onto the railing. I once took a chair lift (in the summer, so you could see much further down as it wasn't covered in snow) and I was just shy of sobbing completely the entire way up.
However, if I'm inside but high up, I'm completely fine. I'll be right up against the window checking out