63 members of the Roma community who have been living at the Ballymun intersection of the M50 are due to be repatriated to Romania tomorrow.
Gardaí say the families left the camp voluntarily this morning.
38 adults and children chose to stay at the roundabout and slip road. They say they will fight any attempts to deport them.
The Garda National Immigration Bureau supervised the departure, which began at 5am this morning.
The GNIB says the people left voluntarily, but support groups say they believed they were being coerced into leaving.
The families were removed to the Balsaskin reception centre beside Dublin Airport.
It is understood they are due to be flown back to Romania at some stage tomorrow.
23 adults and 15 children decided to remain. They have been issued with immigration papers but say they will fight any attempts to deport them.
It is understood at least two of their cases will come before the courts later this week.
Roma will be removed - Lenihan
The Travellers' rights group, Pavee Point, said earlier that members of the community were called to Ballymun Garda Station at 8pm last night to discuss the options open to the group.
They were offered voluntary repatriation.
Pavee Point representatives remained at the scene overnight and when people left on the buses.
Last night, Minister for Justice Brian Lenihan said he had served deportation notices on members of the group encamped on the roundabout.
He said the Roma community there would be removed from the State unless they could give a valid reason to remain.
Speaking on RTÉ's Questions and Answers, Mr Lenihan said the Romanian community in Ireland had advised him that if the State allowed the Roma people into Ireland, thousands more would follow.