The project was launched by then Chief of Government of Buenos Aires Mauricio Macri in May 2015,[1] and the first call for tender was made three years later.

After the administration led by Javier Milei suspended all the public works in Argentina,[4] the Red de Expresos Regionales continues with no plans for its construction.

The idea of linking the main commuter rail lines of Buenos Aires through a tunnel dates back to 1969, resulting in a 1973 study which suggested creating a Red Expresa Regional.

[8] The project includes the construction of 16 km (9.9 mi) of tunnels to link the three main railway terminals and the construction of five new underground stations: one at each of the terminals, one underneath the Obelisco in the centre of the city and another in the Central Business District underneath the Buenos Aires Central Post Office.

[9][10][11] Perhaps the most notable omission from the project is the inclusion of the Urquiza Line whose terminal as at Federico Lacroze railway station in the West of the city.

However, both lines are having their rolling stock replaced with electrification in mind, with the Belgrano Sur line using new CNR DMUs which have been designed to be easily converted to electric power, while the Belgrano Norte has a similar case with its new Argentine-made Emepa Alerce DMUs which are also designed to be easily converted.

[22] Similarly, the tracks of what was the Buenos Aires and Ensenada Port Railway and the Tranvia del Este provide a north–south connection through the Puerto Madero district, though today these areas have heavy road traffic and would be unsuitable for overground commuter rail.