A weekend of tailbacks and motorists' complaints has prompted Roads Service to review a temporary road lay-out on the new cross-border dual carriageway.
Motorists found themselves stuck in traffic jams near Cloghogue
The road near Newry was opened last week. It was built to cut journey times on the Belfast to Dublin route.
But within hours of the opening ceremony on Thursday, the first queues formed near Cloghogue.
The cross-border project is costing tens of millions of pounds - and work is to begin on a further 12 km stretch.
There were hopes that the opening of the latest section of dual carriageway would solve some problems.
However, motorists found themselves experiencing long queues and plenty of frustration in tailbacks close to Cloghogue.
The Roads Service said its staff would be examining what caused the tailbacks on Sunday.
In a statement, the Department of Regional Development said they would also be monitoring and reviewing the position to see if any minor alterations could be made to the temporary road layout at Cloghogue roundabout.