The Federal District Metro (Portuguese: Metrô do Distrito Federal, commonly called Metrô DF) is the rapid transit system of the Federal District, in Brazil. It is operated by Companhia do Metropolitano do Distrito Federal and was opened in 2001. Currently, Federal District's Metro has 24 stations on two lines, and it runs for . The metro covers the Federal District's main cities at west. Its main problem is the sheer distance between many stations (caused by overall low density, suburban profile for such system), making it only a small part of the transit system of the Federal District and mostly an intercity service, with exceptions in Brasília and Ceilândia. The administrative region of Águas Claras is well-served by the system, making it one of the fastest-growing areas of the Federal District and the most dense. All this is possible thanks to the Signaling and Traffic Control and Automatic Protection System for Trains, which allow the regularity of the interval between trips, speed control and control of the distance between the trains. Electrical, communication and signalling systems work in a redundant way; i.e. if there are flaws in the main system, the second is immediately started. The whole system takes corrective and preventive maintenance daily. History The construction of the Federal District Metro began in 1992, and its first sections started operating in 1999, but because of a backlog of work, the metro was not opened at its originally-scheduled date and time (21 April 1994 at 17:00). Work was finally finished in the beginning of 2001, and commercial service began on 24 September of that year. During the first months, the metro operated only from 10:00 to 16:00 over only of the network of total of . Five more stations were opened in 2008: 108 South, Guariroba, Downtown Ceilândia, North Ceilândia and Ceilândia. 102 South and 112 South stations opened in 2009; Guará station opened in 2010. Operations It operates from 06:00 to 23:30 Mondays to Saturdays, from 07:00 to 19:00 on Sundays. The metro's commercial speed is . The track gauge is and powered by a third rail. Its stations are equipped with stairs and lifts. Tickets and fares The access to Metrô-DF is controlled by electronic entry and exit barriers. To travel on the metro, tickets are unitary, for a single trip, or by a magnetic card, which is inserted into the ticket barriers. The card can be recharged.