Passengers travel on the London train and underground system during the Christmas party season, December 18, 2015. (Photo by Paul Hackett/Reuters)

Travellers wait in queue to test for COVID-19 at a train station in Mumbai, India, Tuesday, November 30, 2021. (Photo by Rafiq Maqbool/AP Photo)

The performers prepare for the show. Fontana, a travelling water circus produced by Cirque Du Liban at Festival City in Dubai. (Photo by Chris Whiteoak/The National)

Travel concept: commercial airplane flying with beautiful charming stewardess on September 12, 2019. (Photo by Volodymyr Tverdokhlib/Alamy Stock Photo)

A woman dressed up for Halloween travels on a Metro train in São Paulo, Brazil on October 30, 2017. (Photo by Cris Faga/Rex Features/Shutterstock)

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

Hindu pilgrims walk along a mountain path as they make their pilgrimage to the sacred Amarnath Cave, one of the most revered Hindu shrines, near Baltal, Kashmir, India. (Photo by Daniel Berehulak)

A devotee of the Chinese Bang Neow Shrine, with two plastic guns pierced through his cheeks, takes part in a street procession celebrating the annual vegetarian festival in Phuket September 29, 2014. The festival, featuring face-piercing, spirit mediums and strict vegetarianism celebrates the local Chinese community's belief that abstinence from meat and various stimulants during the ninth lunar month of the Chinese calendar will help them obtain good health and peace of mind. (Photo by Damir Sagolj/Reuters)