Cleveland Hopkins International Airport (airport code CLE) is located 10 miles south of downtown Cleveland, Ohio. The Rapid Transit Authority (RTA) Red Line takes passengers from the airport to Tower City Center downtown. Located conveniently near both I-71 and I-90, limos, taxis and rental cars are also available. The 36th busiest airport in the US, Hopkins International hosts more than 11 million passengers each year. Nine air carriers provide service with United Airlines using Cleveland as a hub. Cleveland's central US location provides the airport with access to 43 percent of the US population. The airport consists of one passenger terminal divided into four concourses, A, B, C, and D.