Driveway Turnaround Ideas . The circle is 70 feet wide and the pool area has a diameter of 20 feet. Gravel is composed of loose rock. Edina 1 Driveway Design Residential Asphalt and Concrete Specialists from www.drivewaydesign.net Drivable grass systems are made of concrete squares with mesh backing that are strong enough to paved driveways with. The circle is 70 feet wide and the pool area has a diameter of 20 feet. The driveway design has a central pool and fountain.