very rarely, a train is launched with just enough speed to reach the track's highest point, resulting in the train getting stuck on the top. this results in neither a full ride nor a rollback. this happened three times on top thrill dragster. all three times, a ride mechanic had to take an elevator to the top, and give the train a small push so it could complete the ride. it has also happened on stealth at thorpe park during early morning tests. maverick at cedar point tests roll backs every morning during testing.