Minister for Transport Martin Cullen today turned the sod on the final section of the M1 motorway between Dundalk to Newry.
The 14-kilometre stretch will link the N1 in the Republic with the A1 across the Border in the North.
At the northern end it will link with the existing Newry bypass and at the southern end with the M1 Dundalk western bypass, which is being built.
Speaking at a ceremony to mark commencement of the project, Mr Cullen said the €121.9 million project illustrates how all island projects can make a positive economic and community difference to the lives of people North and South.
He said: "Better roads mean a better future for jobs and communities. This vital piece of cross-border infrastructure will lead to safer roads and shorter travel times.
Work is due to be completed in two-and-a-half years' time.
