Comment by metrix

The ”race tracks” are left- and right-hand traffic patterns for arriving aircraft and touch-and-go training, typically used by smaller aircraft. The polylines going from airport to the surroundings are IFR (instrument flight rules) STARs (standard terminal arrival routes) for inbound/outbound planes; each vertex in the line corresponds to a so-called navigation star which usually has a 5-letter name.

Possibly training flights; they will often do racetrack shapes like that for long periods to maintain proficiency with the aircraft type.