The 16km six-station line links Jardim Oceânico in Barra da Tijuca with Nossa Senhora da Paz in Ipanema and will serve the Olympic Village with a journey time of 15 minutes between the two termini. The line is projected to carry 300,000 passengers per day in the first year of operation.

The first test train was hauled by a trackmobile at slow speed in both directions between General Osório and Jardim Oceânico stations. The test train is expected to begin operating under its own power soon when the 750V dc third rail electrification system is energised.

Construction began on the Reais 9.4bn ($US 2.6bn) project in June 2010 and the line is being built by Concessionária Rio Barra, a consortium of Brazilian companies Odebrecht Queiroz Galvão, and Carioco Engenharia under a 25-year build-operate-maintain concession. According to the consortium the project is now 95% complete and the line is on course to open on August 5, the day of the opening ceremony for the Olympics.

Services on the new line will be operated by a fleet of 15 six-car trains supplied by CRRC Changchun Railway Vehicles, China, which are currently being used on lines 1 and 2 pending the opening of Line 4.