A passenger not wearing pants sits in a subway train during the “No Pants Subway Ride” in Prague, Czech Republic, January 10, 2016. The event is an annual flash mob and occurs in different cities around the world in January, according to its organisers. (Photo by David W. Cerny/Reuters)

Police clash with “Occupy Melbourne” protestors on October 21, 2011 in Melbourne, Australia. Protesters and riot police clashed in Melbourne today after police, acting on a Melbourne City Council eviction order, attempted to break up the crowd of hundreds that had been positioned in City Square for a week. (Photo by Mark Dadswell/Getty Images)

Passengers travel in an overcrowded train in the eastern Indian city of Patna, February 23, 2010. (Photo by Krishna Murari Kishan/Reuters)

A dressed up participant without trousers takes part in the 2017 No Pants Subway Ride in New York, the United States, on January 8, 2017. The event, which first took place in New York in 2002, has become a yearly event attended by people in more than 60 cities across the globe. (Photo by Zou Zheng/Xinhua/Sipa USA)

A woman travels on a train stopping at a subway station visited by foreign reporters in central Pyongyang, North Korea on April 14, 2017. (Photo by Damir Sagolj/Reuters)

A visitor takes photos while attending the Dandenong Festival of Lights in the suburb of Dandenong in Melbourne, Australia, September 23, 2015. The month-long festival, set up by the Chinese Cultural Works Light Spectacular, celebrates Chinese culture through a display of hundreds of beautiful and unique silk light displays, according to the event's website. (Photo by Darrin Zammit Lupi/Reuters)

A woman lies face-down on the floor where other race-goers are standing on 2017 Derby Day at Flemington Racecourse on November 4, 2017 in Melbourne, Australia. (Photo by Splash News and Pictures)

Scandinavia, always ahead of the bike infrastructure curve, has something else to share: a self-service cycle lift for hilly roads.