€9.5bn MetroLink will see trains running every three minutes

Artist's impression of the Ballymun station

Dublin will have a Metro, the Transport Minister has said as the business case for the long-delayed plan was unveiled.

Metro projects for Dublin have been in motion for over two decades with over a quarter of a billion euro already spent without a single track having been laid.

However, speaking at the launch of the MetroLink business case, Eamon Ryan said that the project will be delivered.

He said that the confidence came from last year's National Development Plan which committed a €35 billion spending envelope to his department.

Mr Ryan said the plan would "transform public transport" in the capital.

While the project's costings put a higher-end cost of €12.1 billion and an extreme case of €23 billion, Mr Ryan said that the Government expects that the final bill will come in at the lower to mid-range estimates of between €7 billion and €9 billion.

The Minister accepted that the project has been beset by false starts but said that this iteration would have passengers on board in the early 2030s.

"This will be built. Dublin will have a Metro," he said.

Mr Ryan said Ireland's first metro will be transformative and will benefit the economy and society by almost €14bn over 60 years.

An artist's impression of the Tara Street MetroLink entrance at night

Public Expenditure Minister Michael McGrath said the task at hand was to ensure the project progresses in a timely manner with protecting the interests of the taxpayer as a central tenet of the project.

He said a suite of oversight measures had been developed to allow for independent scrutiny of public projects at key decision-making stages.

MetroLink will provide a mostly underground high-frequency rail line between Swords and Dublin city centre via the airport.

The public transport 'megaproject' will include 16 stations and serve communities such as Swords, Ballymun and Glasnevin as well as the city centre, Dublin Airport and major employment, education and transport centres.

Once MetroLink is in operation, there will be trains every three minutes during peak periods, with this potentially rising to every 90 seconds by 2060. The system will be capable of transporting up to 20,000 passengers an hour in each direction.

The service will provide an end-to-end journey time of only 25 minutes.

MetroLink rail project route map

According to Mr Ryan, MetroLink will provide over 1bn carbon neutral, fully electrified passenger trips by the year 2050.

"Over 175,000 people and 250,000 jobs will be accessible to the stations by foot alone. By interchanging with other public transport systems such as Dart and Luas, MetroLink connects to more than a million people in the Dublin area, and more across Ireland," he said.

It is envisaged the transport project will help the public to shift from using private cars to more sustainable travel which is crucial in helping to decarbonise the transport sector in line with Government policy.

Mr Ryan said the MetroLink would be integral to the city and the country's sustainable development in this century and into the next.

A planning application will be submitted to An Bord Pleanála in September, with the procurement process commencing next year.