Work on the long-awaited bypass of Kildare town will begin in the opening days of the New Year.
The £59.4 million project will take more than three years to complete. It is expected to reduce the number of vehicles using Kildare's main street by 17,000 a day, and will relieve one of the worst bottlenecks on the national roads network.
Motorists travelling south for the Christmas period experienced long delays last weekend. The Garda and AA Roadwatch are advising that the same traffic problems will greet people on the return journey over the New Year weekend.
The route of the bypass has been contentious since it was first proposed in 1993.
Kildare County Council and the National Roads Authority received approval for the EU-funded project in 1996.
The proposed route cuts south of the town through an area known as the Curragh Aquifer, part of the 550-acre Pollardstown Fen natural habitat.
In 1998 An Taisce made a complaint to the European Commission in Brussels, stating the proposed bypass - particularly one 3.5-km cutting - could result in the dewatering of the Pollardstown Fen. All work on the project was halted pending the outcome.
To satisfy environmental concerns, this section will be lined with an impermeable membrane.
Termed the "tanking method", this feature is designed to protect local ground water resources and will add £5 million to the overall cost of the project.
The project was given the green light over a year ago. The principal contract for it was signed in November. The chairman of Kildare County Council, Mr Rainsford Hendy, stressed the national significance of the new road. "The traffic gridlock of Kildare town is a familiar sight to everyone, and the N7 cuts the town in half, preventing it from growing. All of the national schools lie to the south of the town while the residential areas are to the north, divided by the busiest route in Ireland.
"The town can't expand until those 17,000 vehicles that pass through the centre on a daily basis are diverted," he said.
Mr Hendy pointed out that at present some 80 per cent of traffic from Dublin to the rest of Ireland passes through Co Kildare.
The new 12-km motorway will join the existing Curragh dual carriageway 3 km east of Kildare town and will rejoin the existing N7 a little over 1 km east of Monasterevin.
Eventually, it will be joined by the Monasterevin (HeathMayfield) bypass and the new route will form part of a motorway between Dublin and Portlaoise.