July 9 Avenue (Spanish: ) is a major thoroughfare in the city centre of Buenos Aires, Argentina. Its name honors Argentina's Independence Day, July 9, 1816.

The avenue runs around to the west of the Río de la Plata waterfront, from the Retiro district in the north to Constitución station in the south. The avenue has up to seven lanes in each direction and is flanked on either side by parallel streets of two lanes each. Through the centre of the avenue runs one of the city's Metrobus (Bus rapid transit) corridors, which stretches and was inaugurated in July 2013. There are two wide medians between the side streets and the main road. It is currently the widest avenue in the world.

Avenida 9 de Julio

The northern end of the avenue is connected to the Arturo Illia expressway (which connects to Jorge Newbery airport and the Pan-American highway) and to Libertador avenue. The southern end is connected to the 25 de Mayo tollway (serving the west side of Greater Buenos Aires as well as Ezeiza airport) and the 9 de Julio elevated expressway which provides access to the two main southbound roads out of the city (route 1 to La Plata and route 2 to Mar del Plata). The Republic Square is located on the intersection of this Avenue with the Corrientes Avenue and on that point is sited the Obelisk of Buenos Aires.

Avenida 9 de Julio

History and overview

The idea of constructing July 9 Avenue () was proposed during the time of Mayor Francisco Seeber (1889–1890). It was hoped to be like an artery that crossed through from the north to the south, connecting the two. Later it was included in diverse plans and projects, but it was not until 1912 that it passed the National Law 8.855 that authorized the municipality to carry it out. It was intended for public use within the blocks between the streets of Cerrito and Lima and Carlos Pellegrini to Bernardo de Irigoyen, from the Paseo de Julio (Avenida del Libertador) to Brazil (Barrio de Constitución) with the goal of constructing a 33-meter-wide central avenue, flanked with two wide streets and by public or private buildings of characterized style and special architecture built on the resulting land. The sale would be part of the financial funds along with the loan issued by the local government of 25 million gold pesos. This money would come directly from the income of the local government and with a 10% of direct contribution from the nation. If the central part corresponded well with the north–south axis, the project would complement the streets running from east to west and having two round-abouts: one located at the intersection of May Avenue (Avenida de Mayo) and the other at the intersection of Corrientes (Corrientes Avenue).

Avenida 9 de Julio

As soon as the respective law was sanctioned, Mayor Anchorena made a step toward completion by inaugurating it for the Centennial of Independence (1916). The Municipality of the city of Buenos Aires started the acquisition of all the properties located particular track with an investment of 50,000,000 of the currency of that time (peso moneda nacional). However, the municipality was not well-equipped enough with legal instruments and sufficient finances in order to further the ventures of construction of such a size in a sustainable and orderly way. The expropriations were carried out in a gradual and alternated way, such that it was slow in completing the tasks at hand. This created a grave burden on the municipal treasury. This setback also had negative effects on the building developments in the central zone. With this, many buildings were degraded and were either abandoned or demolished. The matter generated a political and financial crisis of large proportions, which were also aggravated by the outbreak of the Great War and the proximity of the first democratic elections that were to occur with the resignation of Mayor Anchorena and with the closing of the Municipal Counsel in 1915.

The idea to construct the July 9 Avenue was maintained in the plan of 1925 where it was integrated into the North and South diagonals (proposed in 1919), forming at the ends two central monuments. The avenue's unusual width is because it spans an entire city block, the distance between two streets in the checkerboard pattern used in Buenos Aires. The distance between adjacent streets is roughly 110 m, greater than the distance between streets in Manhattan. The street flanking 9 de Julio to the east is called Carlos Pellegrini (north of Rivadavia) and Bernardo de Irigoyen (south of Rivadavia). The street flanking 9 de Julio to the west is called Cerrito (north of Rivadavia) and Lima (south of Rivadavia).