The scheme represents a 5.9km addition to the city’s north-south running Luas green line. Connecting St Stephen’s Green in the city centre to Broombridge on Dublin’s north side, it includes 13 new tram stops and creates a new interchange with the east-west red line.

The project completed on time with a budget of around £285M and is expected to increase by several million the number of tram journeys taken in Dublin every year.

It also seeks to encourage mode shift away from the private car, easing congestion in the city centre and improving air quality.

However the new service experienced early teething problems on Monday when commuters reported gridlock as a result of its introduction. These problems have lessened during subsequent peak periods.

Commenting on the project’s completion, sponsoring agency Transport Infrastructure Ireland’s chief executive Michael Nolan said: “This extension to the city’s public transport infrastructure system will transform how Dublin connects and works,” opening up new areas to the benefits of a tram system.

The National Transport Authority’s chief executive Anne Graham added: “I look forward to the positive impact that the extended Green Line will have in alleviating congestion and enhancing the public transport experience for commuters.

“It is becoming increasingly clear that as a country we need to show how serious we are about reducing emissions of harmful greenhouse gases. Extending the Green Line is a significant step in that direction, but we can and we will do more.”

The project was delivered by main contractor Sisk Steconfer joint venture. It includes a new ‘loop’ in the city centre and features an extended off street section to the north.

♦ UK tram operators were issued with a series of safety recommendations last week as the Rail Accident Investigation Branch published its final report into last year’s Croydon tram incident, which killed seven people.

The tram overturned last November when it entered a tight bend too fast. The RAIB’s investigation concluded that the incident was likely caused by a loss of driver awareness, possibly due to fatigue.

Recommendations include the introduction of technology such as automatic braking and systems to monitor driver alertness – which Transport for London has now rolled out – and the launch of a dedicated safety body for UK tramways.

(Photo: Luas Cross City)