Up to 45 Traveller caravans moved off the central reservation of the M1 near Dundalk, Co Louth, tonight after being serviced with notices by gardaí.
The caravans had been parked illegally in the middle of the north and south-bound lanes of the motorway since Friday evening.
There are more than 150 men, women and children living in the caravans at a point where the Dublin - Dundalk motorway ends.
A 3.30 p.m. deadline for the Travellers to leave expired this afternoon and notices were officially served on the occupants ordering them to leave within a reasonable time. They are believed to have moved northwards.