The phrase "smooth ride" refers to a pleasant, comfortable and trouble-free journey or experience. It implies that there were no unexpected bumps, delays, or difficulties along the way, making for an easy and enjoyable trip. The term can be used in various contexts such as describing a car ride, flight, roller coaster, or any other activity where one might encounter roughness or discomfort. In essence, it means that everything went according to plan with no hiccups or complications.