Shaped and channeled parking lots

At some driving ranges (golf) the grounds have been landscaped to incorporate contours, slopes, high spots etc, that channel all the golf balls to central gathering points, like a drain, where they collect and are mechanically delievered back to the pro shop, similar to bowling bowls. Railroad switching yards use the same principal to marshall empty box cars. A parking lot could be designed to incorporate gravity in the same fashion, using a slight grade and sweeping channels the carts will do the slow mosey to gathering points, where a conveyor belt will hook onto them and bring them back to shopping cart central.