Route marker for Expressway 1 (E1) the route designation for North Luzon Expressway, Subic–Clark–Tarlac Expressway (Mabalacat to Tarlac segment), and Tarlac–Pangasinan–La Union Expressway.
Sign dimensions from Highway Safety Design Standards: Part 2 : Road Signs and Pavement Markings, page A78
Department of Public Works and Highways, Hushskyliner and HueMan1