I found that a lot of my dreams have transportation in them.. Whether it's a boat, car, plane, skytrain etc. I don't really like using these to get lucid though.. I find it rarely works. A certain hotel that I've been visiting every once in a while, average is about once a year ever since grade 3 or something ridiculous like that (I'm in university now). I've come to find these hotel dreams pretty meaningful, which I almost never do with dreams. And I've only been lucid once with the hotel. It felt really weird and uncomfortable to be lucid in this really familiar (yet artificial) hotel. So I just prefer to let those run their course.