Laying out a driveway turnaround
Our home has a portico with a curved drive-through driveway. The "exit" end of the driveway is very steep and effectively blind; when going up it, all you see is sky! We want to abandon and demo the steep driveway if we can incorporate a turnaround ("hammerhead"?) into the entrance driveway so we don't have back-up all the way to the street. Space for the turnaround is tight because of the house, the curve in the driveway, and the grade so we need to keep it as compact as we can. How should this be laid this out so it will accommodate average cars and their turn radius?