Keywords: SR 4021 white sign.svg An example of a reference sign in Pennsylvania based on http //www state-ends com/paends/state/end588at51chippewanoendsign jpg this photo This is on PA 51 north with PA 588 to the right and SR 4021 to the left 70 indicates the section of SR 4021 own SPUI spuiother Pennsylvania Quadrant Route shields 4021 |