gyratory

Moving in a circle, or spirally; revolving; whirling around.

In the late eighties and early nineties several new types of movable spans were advocated , including the pull-back draw, the jackknife span, the bob-tail swing, the horizontal-folding draw, the shearpole draw, the gyratory lift, the transbordeur, the double-cantilever swing, several types of bascule, and the vertical lift.

A large traffic roundabout with non-standard lane markings or priorities, or with buildings on the central island.