What is the banked oval arena used for track cycling called?

The banked oval arena used for track cycling is called a velodrome.

A velodrome is a purpose-built venue for track cycling, typically featuring two straights joined by steeply banked turns. The banking, or cant, helps riders maintain speed while leaning into the curve and keeps their bicycles relatively perpendicular to the track surface.

The earliest velodromes appeared in the late 1870s, when organized bicycle racing was expanding. Early tracks varied widely in length, shape, and surface. International competition gradually encouraged standardization, and modern Olympic and world-championship velodromes generally use a 250-metre lap.

The track is marked with lines that guide racing tactics, including the black measurement line and the red sprinter's line. Track bicycles used there usually have one fixed gear and no brakes, allowing riders to slow by resisting the pedals. “Piste” refers more generally to a track or course, while “autodrome” is associated with motor racing, making them poor substitutes.