The dual carriageway continues in Ireland as the N1, which from Ballymascanlon in County Louth onwards is under motorway regulations and signed as the M1 motorway. The road follows the M1 south to Dublin, where, in the northern suburbs, it meets Dublin's ring road, the M50 motorway. It follows the M50 through the outer suburbs of Dublin until it meets the short M11 motorway near Shankill. The M11 continues as a dual carriageway, the N11, south of Bray in County Wicklow. This section passes through the Glen of the DownsNature Reserve and is dual carriageway until Coynes Cross, north of Wicklow. It becomes motorway once more until just north of Oylegate in County Wexford. Following this, the remainder of the route in Ireland is single carriageway and passes through a number of villages. The N11 continues to Wexford, where at a junction outside the town it meets the N25 road from Cork. The route follows the N25 to its final destination in Ireland of Rosslare Europort.
All remaining sections of the N11 (and therefore E1) outside of Dublin are due to be replaced by motorways or dual carriageways.[1][2][3]
The E1 has two sections in Spain. The northern section is between Ferrol and Tui at the Portuguese border. It follows the motorway AP-9, a.k.a. The Atlantic Axis, which connects the Galician cities of Ferrol, A Coruña, Santiago de Compostela, Pontevedra and Vigo, continuing south towards Tui. The E1 follows the motorway A-55 near the city of Tui to the Portuguese border at the river Minho.
In the section Aveiro Norte – Lisbon of the A1, the E1 follows the same route as the E80. In that section the E80 signage prevails over the E1 signage, the latter rarely appearing.
The second Spanish section is between Ayamonte at the Portuguese border and Seville. It follows the motorway A-49, and passes near the city of Huelva. The border is at the Guadiana river.
