A revised plan for Dublin's MetroLink will see Luas Green Line services unaffected during construction.
The metro service will run from Estuary, north of Swords to Dublin’s south city, serving Dublin Airport and the city centre.
The National Transport Authority (NTA) and Transport Infrastructure Ireland (TII) have announced details of the preferred route.
This follows on from a public consultation on the emerging preferred route last year.
During the consultation process, the NTA and TII said "issues came to light" and the revised route "addresses the concerns raised."
However the revised route will be shorter than the original plan, stopping at Charlemont instead of running out to Sandyford as part of an upgraded Luas system.
Na Fianna pitches
Among the major changes, construction in the Mobhi Road area will no longer require the acquisition of a pitch belonging to Na Fianna.
Originally it was proposed that pitches at Na Fianna and the adjacent Home Farm FC would be temporarily acquired for a seven-year period of construction.
In consultation with Home Farm FC, they now propose to construct a more "compact station" under their pitch.
The pitch will be unavailable during the estimated three-year construction process - but will be fully restored afterwards.
However there will be no impact on Na Fianna pitches.
A second significant change is the arrangement around Charlemont.
The route published last year included a proposal to upgrade the Luas Green Line to Metro standard.
It is projected that the number of people seeking to travel on the Green Line in future years will exceed the capacity of the Luas system, requiring an upgrade.
But the new plan has said that upgrade is not expected to be needed for some time - perhaps 20 years or so.
The NTA and TII explained: "During consultation a concern arose about the need to close the Green Line for a prolonged period during an upgrade.
"Acknowledging these concerns, an alternative approach has been developed that allows the new section of metro line to be built now, with the Green Line conversion to metro, to occur at an appropriate point in the future."
The revised plan is to develop the section from Swords to Charlemont with an interchange from Metro to Luas at Charlemont for passengers.
It added that the required tunnel boring works to allow the future connection to the existing Luas line will be completed as part of this current phase.
Last month, Transport Minister Shane Ross said any MetroLink plan involving Luas disruption would be "totally unacceptable".
He suggested: "Such a move could prevent commuters and travellers from getting into the city and would worsen traffic for all."
In the city centre, changes have been made to the plan that will reduce disruption and make it easier for other public transport services to continue to operate.
On O’Connell Street, it had been suggested to build an integrated station under what was the old Carlton Cinema.
The revised plan noted: "The location and construction of this station in the original proposal would have presented a significant challenge to Luas services, bus services, and vehicular traffic on O’Connell Street.
"We are working with the owners of this property with a view to the site into the proposed development", it added.
While disruption at St Stephen’s Green will also be reduced under the new plans.
This station will be located, as previously proposed, at St Stephen’s Green East - but it is being moved slightly south-west so that Hume Street can remain open during construction and to avoid closing the road.
This will avoid a major sewer that would otherwise require a diversion.
And St Stephen’s Green park itself will be "impacted to a small extent" as a result.
In Ballymun, the station is to be moved a short distance, to be adjacent to the R108, partly under the site of the old shopping centre.
Plans are in place for a new mixed use quarter following its demolition.
"This will cause far less disruption during construction and we believe is a much better all-around solution for Ballymun", the statement said.
While the number of homes that will need to be acquired for the project has gone down from 105 in last year’s plan to 85 in the revised plan.
For example, an apartment building near Glasnevin Station - which is currently home to about 40 people - will no longer need to be acquired.
Outlining the changes in the Dáil, Taoiseach Leo Varadkar said: "The tunnel will stop in Ranelagh and the Luas south of there, the Green Line, will be very significantly upgraded.
"The reason why they decided not to go the whole way down that line is because it would involve closing the Luas for two to four years - which they have determined, and I agree, wasn't really a viable option.
"I do think we need to be open to suggestions as to where the tunnel should go from there".
It is expected that a Railway Order application will be made in 2020, with a decision the following year.
Construction of the MetroLink is likely to take six to seven years.
Anne Graham, CEO of the National Transport Authority said: “There are very significant benefits associated with MetroLink, particularly in terms of the integrated transport system that it will bring about for Dublin.
“For example, thanks to MetroLink, there will finally be a rail link to Dublin Airport, and with easy interchange with other modes including bus, Dart and commuter rail, MetroLink will make it easier than ever to move into and around the capital.
"It is also of benefit in providing a more sustainable transport alternative and by providing a great incentive to get people out of their cars and on to public transport."
The nine kilometre route will connect Swords, Dublin Airport, the city centre and Charlemont.
There will be a travel time of 20 minutes from the city to Dublin Airport, and 25 minutes from the city centre to Swords.
The MetroLink will have 30 trains per hour in each direction serving 15 new Metro stations.
It will create about 4,000 jobs during construction.