No, the responsibility for providing a safe driveway is that of the driveway owner.  A sign does not improve the view or make the driveway safer.  Vehicles entering the road from driveways are required to yield to traffic on the road.  For vegetation along the highway right-of-way obscuring the sight distance, call your county maintenance unit.  The DOT allows plastic mirrors to be installed on the right-of-way.  These are available at office supply stores.  Permission from the DOT should be secured with an "encroachment" agreement;  these are available at our District Offices.  The recommended treatment includes reviewing the appropriate speed limit.