(Video Credit: YouTube/Daniel Smith)

Various transportation modes for public commute all over Sydney were filled up with bare legs from majority of the public in celebration of the yearly No Pants Commute day or the 13th annual No Pants Subway Ride.

It was also celebrated by commuters from other countries like Hong Kong and China who went on with their daily commute routine without wearing any trousers or pants on. It was first initiated way back in 2002 by a U.S. Improv group called Improv Everywhere in New York.

About 12 years ago, there were only seven individuals who participated during the event, and now, its success is measured by thousands of those who join in capital cities all over the world. Its organisers even consider it as a silly kind of celebration. The instructions are simple: all those who will participate would have to commute without any pants on. It will certainly bring shock to many and even make others laugh, but it's the main purpose of it.

It is also encouraged that interesting and uniquely designed underpants be worn to create more impact on bystanders everywhere. Those who will participate are also not allowed to talk to each other but must carry on with what they usually do too during their daily commute, like reading a newspaper or a book on the train.

The organisers also advised the participants that once they are asked why they do not have any pants on, all they need to say is that they forgot to wear pants for that day. "Be nice, friendly and remain calm," the organisers noted.

A small group decided to drop their pants on within the Sydney city circle loop train, while in Melbourne and Adelaide, a no trousers tram ride was held too. Forty people were also spotted joining the fun on a Hong Kong subway train that included a 37-year-old Aussie mother by the name of Bess Hepworth, along with her son.

On the other hand, just a handful of trouserless people were seen in Beijing, riding a subway, attracting a lot of shocked onlookers.

The founders of the No Pants Day event expect about 4,000 participants in the New York event this year with more than 60 cities from around the globe.