Much of the open world of Sunset Overdrive was created using procedural systems and automation. Using a few curves, an artist can lay out a city of streets, a network of railroad tracks, or the ocean from the shores to the horizon. In minutes, a new area of the game with final assets is playable in engine. The rapid turnaround allowed designers to test many possible street layouts and elevations, and view final (or close to final) geometry, before involving environment artists. Once turned over, environment artists could concentrate on the buildings, instead of hand-modeling custom ground. This session explains the ground and many other systems used to create Sunset City.