Airports of London Heathrow, more than Paris and Frankfurt combined, and Heathrow is the European terminus for 11 of the 25 busiest north Atlantic routes. The busiest long-haul route in the world is between London (Heathrow and Gatwick) and New York (JFK and Newark), with a total of 3,898,460 passengers travelling between the two cities in 2011. Airports of London The metropolitan area of London, England, United Kingdom is served by six international airports and several smaller airports. Together, they make the busiest airport system in the world by passenger numbers and the second-busiest by aircraft movements. In 2016, the six airports handled
London Underground and the mechanisms are regularly degreased to lower the potential for fires. The only wooden escalator not to be replaced was at Greenford station, which remained until October 2015 when TfL replaced it with the first incline lift on the UK transport network. There are 426 escalators on the London Underground system and the longest, at , is at Angel. The shortest, at Stratford, gives a vertical rise of . There are 184 lifts, and numbers have increased in recent years because of investment making tube stations accessible. Over 28 stations will have lifts installed over the next 10 years,