The Minister for Transport, Mr Brennan, yesterday officially opened the Drummartin link road, which provides a direct link to the M50 motorway from Sandyford business park and industrial estate.
Mr Brennan said work on the South Eastern motorway was progressing well, apart from the Carrickmines section.
He had been informed by the National Roads Authority that two sections of the road - one leading to the future Sandyford interchange and the other from beyond Carrickmines to the N11 - would be open to traffic before December.
"The completion of the entire motorway route, including the Carrickmines section, is of vital importance to the overall transport strategy for Dublin. It is a key ingredient in the plan to significantly improve conditions for road users and unclog the traffic bottlenecks that ensnare tens of thousands of cars at peak times," he said.
"I am confident that the motorway can be completed by autumn 2005 once the legal issues relating to the archaeological works at Carrickmines are resolved."
He said the Minister for the Environment, Mr Cullen, was "well advanced" in preparing legislation to rectify the Carrickmines issue.
The nine-kilometre South Eastern motorway will complete Dublin's motorway bypass. It will link the M11 and the M1, at an estimated cost of €595 million.