A new "third tier" may have to be built at every interchange on Dublin's M50 motorway, at a cost of £20 million each, to eliminate growing congestion caused by faults in their design, according to the National Roads Authority.
At a press briefing yesterday to announce its road programme for 1998, Mr Michael Tobin, chief executive of the NRA, blamed lack of money for the decision to opt for roundabout-style interchanges rather than the more common, but expensive, clover-leaf design.
He conceded that an extra tier at each interchange would make it easier for commuters to drive into town, contrary to current transport policy. "Without a doubt, the improvement of the major arteries leading into Dublin is expanding the commuter belt."
New slip roads are to be provided for the M50 at the Red Cow roundabout on the Naas Road and at Palmerstown, on the Lucan road, in an effort to reduce congestion. But with traffic volumes growing by 6 per cent per annum, it is clear this will not be enough.
Mr Tobin revealed that National Toll Roads plc, which operates the West Link toll bridge, is now considering plans to double its capacity by "duplicating" the existing bridge, to the east of the existing structure. An environmental impact study is already being prepared.
He said the NRA expected that work would start by early April on the next phase of the M50 - the long-delayed Southern Cross route, between Balrothery and Kellystown. Tenders are being evaluated for this £88 million project, which would take more than two years to build.
He noted that a public inquiry into the proposed South Eastern Motorway, to link the Southern Cross with the Bray-Shankill bypass, would open next Tuesday. "We're hoping to see work in progress on this £140 million scheme before the end of 1999."
The NRA's chairman, Mr Liam Connellan, said it would be investing over £1/4 billion in the national road network during 1998. Altogether, including EU aid, £288 million would be spent, compared to £260 million last year.
Nine major projects would be completed including the Lee Tunnel in Cork and the Balbriggan and Arklow bypass schemes, he said. Overall, 27 of the 44 major road schemes in the 1994-1999 programme were completed and 12 more under construction. On the Dublin Port Tunnel, Mr Tobin said the City Council's decision to relocate its portals further north, in an effort to placate residents of Whitehall, would add £30 million to the cost, bringing the latest estimate to £177 million - and not £195 million, as reported.
He said the consultants were finalising a revised environmental impact statement on the scheme. A Bill had also been published before Christmas to "put beyond doubt" the right of road authorities to build motorways in tunnels, underneath people's homes.
Assuming this Bill is passed, Dublin Corporation would then be free to make a motorway scheme for the port tunnel, which would then go to a public inquiry.
"Our objective would be to get it started by the end of next year, which means it should be completed by 2004," Mr Tobin said.
