Construction began in November 2010 and the $US 1.88bn north-south line was built by the Linea Uno consortium of FCC Spain, and Odebrecht, Brazil, which is also constructing a 2.1km extension north from Los Andes to San Isidro and an additional intermediate station at El Ingenio.

Services are operated by a fleet of 19 three-car Metropolis trains supplied by Alstom's Santa Perpetua plant in Spain. Each train can accommodate up to 600 passengers, and services will operate at 3.5-minute headways initially, which will enable the 14-station line to carry up to 15,000 passengers per hour per direction during peak periods. However, by running five-car trains at 1.5-minute headways it will be possible to ramp up capacity to 40,000 passengers per hour per direction in the future.

Alstom is responsible for engineering, integration and commissioning of the electromechanical works for the project. In addition to supplying the rolling stock, Alstom is installing traction substations and its Urbalis communications-based train control (CBTC) system.

During the opening ceremony the president announced a request for proposals will be issued shortly for the construction of the $US 2bn Line 2. This 24km line will mostly run on an elevated alignment.