line would have automatic trains and platform screen doors. Line G will connect Retiro and Caballito/Villa Crespo; 12.5 km long with 15 new stations. Originally, construction was due to start in 2012–2013, however city legislators opposed the turnkey construction proposed by Chinese firms since the total cost would have been 30% higherthan if it was done with local companies. After this, it was decided to prioritise the other construction projects in the network. Line I will run Parque Chacabuco to Ciudad Universitaria with 18 new stations. The route length is 12.6 km. The future of this line (which had the lowest priority in the expansion plans) is currently uncertain since it has been proposed that a Metrobus line be built instead, which would follow the same trajectory as the line. PETERS plan In October 2015, the city of Buenos Aires together with the Inter-American Development Bank presented a 150-page plan for the Underground called the Strategic and Technical Plan for the Expansion of the Subterranean Network (Plan Estratégico y Técnico para la Expansión de la Red de Subtes, or PETERS), highlighting past expansion efforts and the need to adapt plans to the current needs of the city. In this version of the Underground, Line I is cancelled while Line G takes a different route through the centre of the city terminating at Constitucion railway station after going through the neighbourhood of San Telmo, rather than through Retiro railway station. Other changes include a Retiro Norte node where lines F and H terminate, rather than at Plaza Italia and Retiro respectively, while Line E is extended to Plaza Italia from Retiro – a segment which in the original plan was part of Line F. In these plans, Line C is extended both northwards in a loop to Retiro bus station and southwards to the Buenos Aires Belgrano Sur Line railway station minor terminal. Such plans are subject to approval by the Buenos Aires City Legislature and would mean the annulment of many of the existing expansion plans outlined in Law 670. Some criticisms include the failure of the PETERS plan to account for the extension of the Belgrano Sur Line to Constitucion railway station, meaning that Line C's extension to the minor Buenos Aires terminal would be redundant, and that the Retiro Norte node would also be made redundant by the planned Red de Expresos Regionales commuter rail tunnels which are