 Sections of the N25, N11 and N1 roads form the Republic of Ireland part of route E1 (or E01); sections of the N7, N18 and N19 roads form part of route E20; the N8 forms part of route E201 and sections of the N25 form part of route E30.E-route numbers are placed on some route confirmation signs on certain sections of these roads.From the 1920s through to 1977, Irish roads had been numbered under a system of Trunk Roads and link roads (see Trunk Roads in Ireland for details).