Construction work began on a new tram depot on the edge of the Grünewald Forest and the Kirchberg quarter of Luxembourg City in January 2015,[5] with the first tracks of the T1 tramline being laid in July 2016.

On 10 December 2017, the first phase of the route opened with trams running from the depot, along Avenue John F. Kennedy, past the European district, the location of many EU institutions, before terminating at the Grand Duchess Charlotte Bridge.

[9][10][11] The second phase opened on 27 July 2018; it extended tram services across the Grand Duchess Charlotte Bridge to Place de l'Étoile in the Limpertsberg quarter.

[12][13] Opening on 13 December 2020, the third phase saw the line extend into the historical Ville Haute quarter, across the Adolphe Bridge, along the Avenue de la Liberté, before terminating at Luxembourg railway station for interchanges between national and international heavy rail services.

[16][17] On 7 July 2024, the fifth phase extended the line southwestwards from Bonnevoie, via Howald railway station to the business district in Cloche d'Or, Gasperich, before terminating at Luxembourg's new national stadium.

[18] The final phase of the route, estimated to be completed by early 2025, will extend the line eastwards from the tram depot on the edge of Kirchberg to Senningerberg before terminating at Luxembourg Airport.