The 3.9km section of the 1676mm-gauge double-track third rail electrified line in the city’s suburbs has been rebuilt on concrete viaducts 10-14m above the former track bed. The new line starts around 6km from the Retiro Mitre terminus and includes two new stations built to replace the former at-grade stations. The Belgrano Central station with 220m-long platforms opened on May 11 while the Lisandro de la Torre replacement station will open in October.

The new elevated section of line eliminates eight level crossings and re-opens two streets that were effectively cut in half by the railway line. The project’s aims to improve rail reliability and safety whilst also reducing road traffic delays caused by frequent closure of level crossings in a densely populated part of the city - around 1 million people live in the area near the line. The 30km long Retiro - Tigre line is used by 98 trains in each direction per day, and carries 100,000 passengers, making it one of the busiest in South America.

Similar projects to elevate heavily used railway lines and remove level crossings are underway elsewhere in Buenos Aires on sections of the San Martín Railway (LSM: Retiro Line to Pilar) and the Belgrano Sur Railway (being diverted on viaduct to Plaza Constitución station). These are due to open in the next year or two.

Construction of the project began in May 2018 using pre-fabricated concrete sections which incorporate noise reducing barriers. Services on the existing line were maintained during most of the construction period apart from in early 2019 when train services were restricted to the northern Núñez - Tigre section.