If you have the space in your front yard, a half circle driveway adds flow to a landscape and softens the angles of a home. Paving a driveway is labor-intensive regardless of the shape of the driveway. The process of laying the course of a driveway in a half circle is not complicated, but it calls for careful measurements to ensure the driveway is sized right to accommodate turning vehicles.
Lay down parallel ropes to mark the approximate inside and outside edges of the driveway site. The outer diameter of the half circle should be at least 75 feet, and the width of the driveway should be 15 feet to enable vehicles to make the turn of the curved driveway with ease. If the curve is too tight, large vehicles will not be able to drive from the entrance to the exit.
Cut a string 37 1/2 feet long. Have a helper stand on the curb where the center of the half circle will fall, holding on to one end of the string. Hold the other end taut and walk in a half circle, adjusting the ropes on the ground as you go to trace the outer border of the driveway. Use measuring tape to verify that the length between the two outer edges of the driveway is 75 feet.
Repeat Step 2 with a string 22 1/2 feet long to outline the inner border of the driveway. When you're finished, the outlined driveway will be 15 feet wide.
Dig the site at least 12 inches deep with a shovel to remove all topsoil. Dump it on a tarp at the center of the half circle and plan to use it for filling out lower-lying areas. Beginning at the outer edge, dig an extra inch down with every 4 feet of distance toward the inner edge to give the driveway a mild slope away from the house.
Push a compactor machine over the exposed dirt to stabilize it.
Shovel 3/4-inch aggregate into the site until you have a 4-inch thick layer. Compact the rocks until they don't move under the machine, and then add another 4-inch thick layer and compact it. The gravel base will support the pavement under heavy weight loads, while allowing water to travel from beneath the surface.
Line the inner walls of both sides with strips of flexible edging restraints. Hammer 12-inch lawn spikes in the holes along the bottom of the restraints through the gravel base and into the ground.
Spread a 1-inch bed of course sand over the aggregate. Spread it smooth by laying a long board across the width and pulling it slowly over the site.
Begin at one end of the site and lay a paving block, brick, stone or other type of paving material on top of the sand so it's flush against the edging. Set the next piece adjacent to the first in the planned pattern.
Cut the end blocks or bricks as needed with a splitter or masonry saw. Continue setting each paver until the driveway is complete.
Fill the joints with polymeric sand by pouring it over the driveway and pushing it down with a firm broom. Brush off any excess and sprinkle the surface with a hose so the sand will harden.