I decided to check with Wikipedia on the size of that street. Here’s the facts. It doesn’t mention that there is a subway below or that the “medians” are parks between the “7” and “2” lanes. It is unbelievably huge!!!
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 (Buenos Aires) (Bus rapid transit) corridors, which stretches 3 kilometres (1.9 mi) and was inaugurated in July 2013. There are two wide medians between the side streets and the main road.