provide an air shuttle service between OR Tambo International Airport and Cape Town International Airport with up to half-hourly headways TAP Portugal's Ponte Aérea (Air Bridge) service between Lisbon and Porto in Portugal. Turkish Airlines and Pegasus Airlines 64 daily flight between İstanbul Atatürk Airport and Izmir Airport. This route is the second-busiest route in Europe. SAS also has a shuttle on the triangular route between Oslo Airport, Gardermoen (Norway), Stockholm-Arlanda Airport (Sweden) and Copenhagen Airport (Denmark) with up to hourly headways. The Carrasco International Airport in Uruguay has an air bridge to Buenos Aires airports Aeroparque Jorge Newbery and Ezeiza International Airport. The route between Dublin and London is served by over 640 flights each week, with departures occurring on average every 20 minutes in each direction. The majority of the flights are operated by Aer Lingus, Ryanair and British Airways but CityJet also operates on the route. The route competes for the title of the busiest international air route in the world. The routes between Hong Kong and Taipei, Taiwan (Republic of China), and between Hong Kong and Bangkok, Thailand, are served by multiple carriers providing frequent service with a frequency less than an hour during day time. Qantas and QantasLink 'CityFlyer' service offers flights between major Australian capital cities on weekdays, with complimentary alcoholic afternoon drinks, newspapers, flexible fares and more frequent schedules. The busiest air routes in the world involve pairs of large cities in close proximity that rely on air transport due to a lack of high-speed rail, and the distance is large enough to discourage car driving. Several of the airports are on islands without road connection to the mainland. See also World's busiest passenger air routes References Shuttle Airline routes