Dreaming of a thrill ride, such as a roller coaster, can mean you are experiencing the following in your real life, or that you feel you have too much or not enough of one of these things:
"Ups and downs" or changes
Unpredictability
Excitement or thrills
Following someone else's "path," expectations, or orders
A thrill ride can also represent a journey or a certain series of events in your real life, where something new happened around each turn.