Phoenix Sky Harbor International Airport is the largest and busiest airport in Arizona (and one of the top ten busiest in the United States). Making life somewhat easier, the new PHX Sky Train is now operating and transporting travelers between Valley Metro Rail at 44th and Washington streets and the airport terminals terminating at the Rental Car Center. The rail has made it much easier for passengers to get to and around the airport. The convenience of the PHX Sky Train is just one reason why Sky Harbor has earned itself the accolade America’s Friendliest Airport.