It is very common for a circle-to-land maneuver to be executed during a straight-in approach to a different runway, e.g., an ILS approach to one runway, followed by a low-altitude transition, ending in a landing on another (not necessarily parallel) runway. This way, approach procedures to one runway can be used to land on any runway at the airport, as the other runways might lack instrument procedures or their approaches cannot be used for other reasons (traffic considerations, navigation aids being out of service, etc.).