Amsterdam’s Schiphol airport added 4.8 million passengers last year with the help of a six-runway setup that’s unique in Europe, putting it almost level with Paris Charles de Gaulle as the region’s second-busiest hub.

Schiphol, home base to KLM, attracted 68.4 million travelers, consolidating its lead over Frankfurt and putting it within 1 million of the total at Charles de Gaulle, which is the headquarters of the Dutch carrier’s parent Air France.

London Heathrow remained Europe’s leading airport despite the constraints of only two runways as airlines turned to bigger planes to boost capacity. The U.K. hub isn’t due to get a third strip until 2025 at least.

Amsterdam lifted passenger numbers 7.7 percent in the 12 months, the most among Europe’s top bases, following 9.1 percent growth in 2016. That’s contributed 10.2 million more travelers in just two years, the equivalent of adding an entire airport such as Glasgow’s main hub.

Schiphol led a surge in passenger numbers across European airports. Charles de Gaulle itself posted a 5.6 percent gain after a flat 2016 as tourist visits to France rebounded from a string of terror attacks, while Frankfurt’s 6.1 percent growth rate, the fastest in six years, was helped by labor peace at Deutsche Lufthansa AG and incentives that brought Ryanair Holdings Plc to the airport.

While Schiphol plans to open a third terminal in 2023, when Frankfurt will also add a new building, its advance could be stymied by a cap on flights at 500,000 a year aimed at curbing noise and pollution. The Dutch hub had almost 497,000 plane movements in 2017, 22,000 more than at Heathrow, aided not only by its multiple runways but the ability to operate 24 hours a day — a freedom many of its European rivals are denied.

Istanbul’s Ataturk hub rebounded from a passenger decline that followed a foiled coup in Turkey in 2016, though it will close once the city’s new airport, slated to open in October, is able to handle sufficient traffic. The replacement hub will start with two runways but has plans for six.

©2018 Bloomberg L.P.

This article was written by Richard Weiss from Bloomberg and was legally licensed through the NewsCred publisher network. Please direct all licensing questions to legal@newscred.com.

Photo Credit: Schipol airport. The airport is adding a third terminal in 2023. Schipol