The San Martín line (LSM) is one of the 7 suburban lines of the Metropolitan Railways of Buenos Aires. It is a commuter train belonging to the national network of General San Martin Railroad, passenger services between Retiro stations, namesake in the Buenos Aires neighborhood, and Dr. Cabred station in the town of Open Door, Luján district. Since March 2, 2015, it is the operation of the state-owned company Trenes Argentinos Operaciones, after more than twenty years of total or partial private management. In 2018, promoted by the government, works began to raise the route between the Palermo and La Paternal stations, among which stands out the demolition of the Bridge of Reconquista with which Juan B. Justo Avenue It crossed at the same time on the layout and on Córdoba Avenue, and the elevation of the stations Villa Crespo (formerly Chacarita) and La Paternal, freeing the passage of many streets.
