A. Madero borough. From there it runs south, through Cuauhtémoc and Benito Juárez, before terminating in the La Joya district of Tlalpan borough, providing a total of 45 stations. It was built in two sections, with a split at Metro Insurgentes, the notional dividing point between the avenue's northern and southern stretches, just south of where Avenida Insurgentes intersects with Paseo de la Reforma. The first line covers a distance of up to , running in a dedicated bus lane built within the central reservation (median) of Avenida de los Insurgentes. Avenida Insurgentes is one of the city's main north–south arterial routes, constitutes a section of the Pan-American Highway, and is reputed to be the longest urban avenue in the world. On its route south from Indios Verdes, the Metrobús also connects with Metro stations at Deportivo 18 de Marzo, Potrero, La Raza, Buenavista, Revolución, Insurgentes, and Chilpancingo, providing connections with Metro Lines 1, 2, 3, 5, 6, and 9. The proposed southward extension of Mexico City Metro Line 7 will also enable that line to connect at the Metrobús' original southernmost station, Doctor Gálvez. The first metrobus service began along the northernmost portion of Line 1 on 19 June 2005. Initial service was from Metro Indios Verdes south to Metro Insurgentes. This was quickly followed by a southward expansion from Metro Insurgentes to MB station Doctor Gálvez, bringing the line length up to . Many of the stations along Line 1 feature cantilevered glass canopies designed by architect Carlos Monge. The original Line 1 was expanded with the inclusion of nine new stations in order to achieve full coverage of Avenida Insurgentes. The southward expansion of service along Line 1 started service on 13 March 2008 and brought the line's length up to . Line 2 Line 2 runs along Eje 4 Sur from Tacubaya in the west, where there is a connection to the Metro Tacubaya station; via Etiopía, Patriotismo and crossing Line 1 (Insurgentes) at Nuevo León, to Tepalcates in the east, where there is a connection to the Metro Tepalcates station. The line opened on 16 December 2008. Line 3 Line 3 runs from Tenayuca northwest of the city southward to Pueblo Santa Cruz Atoyac, where there is connection to Metro Zapata station. According to the Mexican newspaper, El Universal, construction of the first of Línea 3 (line 3) began on 5 March 2010 and was