For the designated THFN, overhead signs shall provide a vertical clearance of not less than the requirement in to the sign, light fixture, or sign bridge over the entire width of the pavement and shoulders. For traffic signals on the THFN, the bottom of the signal housing and any related attachments to a vehicular signal face located over any portion of a highway that can be used by motor vehicles shall be at least 19-ft above the pavement. Refer to the latest version of the and applicable TxDOT standards for additional guidance.