THE Red Cow or 'Mad Cow' roundabout ? gateway to the capital and bugbear of 70,000 drivers daily ? is to be consigned to history following a cabinet decision last Tuesday to endorse a ?600m upgrade of the M50 ring road around Dublin.

Within three years, the roundabout will be replaced by a ?40m three-tier clover leaf junction with the vast majority of traffic seamlessly moving between the state's two busiest roads, the M50 and the N7/Naas road.

The decision eliminates any need to put the Luas line on stilts at the Red Cow. Only 10% of cars using the junction will now interact with the light rail system, and the government believes this will address concerns about the Luas causing gridlock at the interchange. "It will sort out the Red Cow roundabout once and for all, " a government source said.

While some elements of the three-phase plan will not be completed until 2008 at the earliest, Minister for Transport Seamus Brennan has told the National Roads Authority that he wants the Red Cow dealt with immediately.

It is hoped that the new junction can be completed as early as 2006.

Adding a third lane on the key stretch of the M50, between the Red Cow and the Galway interchange will also be fast-tracked.

The plan also includes major upgrading of interchanges where the M50 meets the Galway and Belfast roads and a third lane being added the entire length of each side of the ring road.

Upgrading of the interchanges with the Navan and Ashbourne roads are also included as phase-three longer term objectives.

The M50 is regarded as the most important road in the state with an economic significance that stretches beyond the greater Dublin region. However, it has been beset by major traffic congestion in recent years.

In the 1980s, when the motorway was being constructed, a decision was taken to scrap plans for clover-leaf junctions at key interchanges ? replacing them with slip roads ? because of the state of the public finances.

However, the decision, which saved around ?60m at the time, has been a major factor in the enormous peaktime congestion and will now cost hundreds of millions of euro to rectify.

It is understood that 80% of the ?600m cost will be borne by the private sector. The company chosen to finance the construction project will recoup its investment through toll revenue. The existing toll agreement with NTR expires in 2015, but a new electronic tolling system will be introduced for the period 2015 to 2030 to finance the building of the road.

The National Pension Reserve Fund is likely to make a bid to finance the M50 project. The fund was set up by finance minister Charlie McCreevy to cater for the state's future pension needs and is funded annually by a government contribution of 1% of GNP. If it were successful in its bid, it would be the first time that the fund invested in a domestic infrastructure project ? something that the opposition parties have been demanding.