Horizontal directional drilling (HDD), also known as directional boring or trenchless boring, is a method of installing underground utilities such as pipe, conduit, or cables with minimal impact to the surface. An entrance hole is dug and the bore head inserted. The head digs underground making a path for the pipe or cable to be pulled through to the exit location. The drilled path can be directed under streets, sidewalks, driveways, pipes, and other utilities.