A section of the Dublin-Galway motorway being built by the private sector is costing more per kilometre than a State-financed section of the same route, it has emerged.
In addition, motorists will have to pay tolls for 26 years to use the private-sector section, which opens early next year.
The Kilcock-Kinnegad motorway in Cos Westmeath, Meath and Kildare is being built at an overall cost of about €381 million.
Some €235 million of that is being put forward by the private contractor Westroute JV, a joint venture between SIAC and Spanish multinational Ferrovial Agromán.
The State is contributing €146 million during construction.
At 36 km, the road works out at about €10.6 million per kilometre and costs to the taxpayer will inevitably be higher when more than two decades of toll charges are included.
In comparison, the next section of the same Dublin-Galway motorway, a 28 km route between Kinnegad and Kilbeggan, is to be completely financed by the State using a design-and-build contract.
The budget for the Kinnegad- Kilbeggan section is, according to the National Roads Authority, about €250 million, a figure which works out at about €8.9 million per kilometre .
That is €1.1 million less per kilometre than the private-sector section of the road, and there will be no tolls to pay when the Kinnegad- Kilbeggan road opens.
Although the cost per kilometre formula is a somewhat crude measure of comparison, both sections are connecting stretches of the same overall motorway between Dublin and Galway and both cover similar terrain through the midlands.
Commenting on the comparison, the Labour Party spokeswoman on transport, Ms Róisín Shortall, said the costs called into question the effectiveness of the public-private partnership principle.
She told The Irish Times she had been initially "not enthusiastic" about public-private partnerships because, while they were designed to transfer the burden of cost and risk to the private sector, there was always a premium to pay to the private sector for that transfer. She said the premium being paid by motorists and taxpayers on the West-Link toll bridge had demonstrated that sometimes that could be too high.