Motorists using the M50 should begin to see improvements in traffic flow from next year, Minister for Transport Noel Dempsey predicted.
"I am confident that with the M50 upgrade completed by 2010, traffic congestion and delay will be reduced and road users will be provided with an improved level of service," he said.
"Road users will begin to see significant benefits next year when the first phases of the motorway upgrade are complete and the barrier-free tolling is in place."
He said there had been constant criticism that little or no work was carried out during the evening or weekends. However, night-time work regularly took place within the restrictions of An Bord Pleanála's planning permission, which explicitly forbid heavy construction work during those time periods.
The combination of noise-related working restrictions, imposed through the planning process, meant that the kind of 24/7 round-the-clock operation, which a number of commentators and political representatives had called for, could not be done because it was unlawful.
"These restrictions inevitably mean that the project takes longer to construct than many of us would like," he added.
Mr Dempsey said there was no quick fix for congestion on the M50, and the upgrade, which was costing €1 billion, was being undertaken in three phases.
Once completed, it would expand the capacity of the M50 to deal with at least 50 per cent more traffic than at present, improve average peak hour speeds, reduce traffic congestion on radial routes, N3, N4, N7, and improve traffic flow on the whole of the Dublin road network.
"I am satisfied that no effort is being spared by those responsible for traffic management and law enforcement to alleviate the problems on the M50 insofar as that is possible and I thank them for their efforts," he added.
Mr Dempsey was speaking during a debate on the Roads Bill 2007, paving the way for barrier-free tolling.
Welcoming the Bill, Fine Gael spokeswoman Olivia Mitchell said that it presaged and facilitated the removal of the "hated barriers" on the M50.
"These barriers have caused such misery to commuters over the years. They are adding to the delays, congestion and heartache caused both by the upgrade works and by the recent opening of the Dublin Port Tunnel in tandem with the works," she added.
Labour spokeswoman Róisín Shortall said the need for open-road tolling on the M50 had been obvious for a number of years. "While I welcome the fact that we are making provision for it, we must ask why we have waited until now," she added.
