Query: What main road leads to the airport?
Context: A second level (where tolls are charged) of the Periférico, colloquially called the segundo piso ("second floor"), was officially opened in 2012, with sections still being completed. The Viaducto Miguel Alemán crosses the city east-west from Observatorio to the airport. In 2013 the Supervía Poniente opened, a toll road linking the new Santa Fe business district with southwestern Mexico City.