Services on the Luas Green Line are to be expanded in a €89 million investment announced by Minister for Transport Shane Ross.
The investment, which is to begin next year, will see eight trams being added to the Luas fleet.
The 26 existing Green Line trams are also to be extended by 12m, increasing their passenger capacity.
The existing Luas depot at Sandyford will also be expanded to accommodate the longer trams.
A number of existing Luas platforms will also have to be extended in order to accommodate the longer trams.
The increase in capacity is 1,760 passengers per direction per hour.
The move comes after a recent study by the National Transport Authority found that the Green Line is currently operating at capacity during peak periods, with crowding experienced between the Balally and Ranelagh stops.
The Luas Cross City project, set to be opened to the public on 9 December, is expected to increase demand on Luas services.