SHENZHEN, Jan. 30 -- Sun Shuwen reached his hometown in northwest China's Gansu Province on Thursday, a day before the Chinese Lunar New Year, after a 29-hour car journey from the southern city of Shenzhen.

For a large part of the journey, he and his wife had two strangers for company -- hitchhikers who needed a lift to the central Chinese provinces of Henan and Hubei. The four were beneficiaries of "Shunfengche," a campaign which calls on private car owners to offer free rides to their fellow countrymen during the Spring Festival travel rush.

Sun spent 2,000 yuan (330.7 U.S. dollars) on highway tolls and gas for the homebound travel.

But he was pleased to have been able to lend a hand to two hitchhikers, who had been unable to bag one of the train tickets that are so in demand at this time of year in China. "Their homes were on my way home. Roses given, fragrance in hand," Sun said, using the popular idiom referring to emotional rewards for benevolent acts.

Most of the country's over 260 million migrant workers would move heaven and earth to return home before the Spring Festival, which falls on Jan. 31 this year and commonly denotes a once-a-year chance for them to reunite with family.

This year, the 40-day Spring Festival travel rush, the world's largest seasonal migration of people, will see 3.6 billion passenger trips, nearly 260 million of them by train, according to a government forecast.

Despite the turbo-charged development of China's railways, their capacity is still dwarfed by demand, as trains remain the first choice for long-distance journeys.

Celebrities, including renowned hosts with China Central Television, launched the online Shunfengche scheme in 2012. Literally translating to "hitchhiking," it is particularly intended to help migrant laborers who don't manage to buy homecoming train tickets, and its use is surging as it enters its third year of operation.

Shunfengche matches drivers with hitchhikers. Car owners with free seats and prospective passengers are both asked to register their information online. The details are then shared via the website, microblog and smartphone app.

To ensure safety, the information must be verified and agreements should be signed by both sides.

Thanks to the campaign, over 1,100 hitchhikers enjoyed free journeys back to their hometowns in 2012, while it helped 9,678 people with their homebound journey or return in 2013. A total of 36,294 people have now registered with the website, www.shunfengche.com.

This year's Spring Festival transport rush is expected to last from Jan. 16 to Feb. 24. More than 11,000 people have been fixed up with a homebound journey via the website so far, while the parents of 535 "left-behind" children have hitched lifts home to reunite with their families, according to data from Shunfengche.

Li Huizheng, chairman of a guarantee company in Shenzhen, offered a free ride to two migrant workers after he found their information on the website.

Li himself migrated to the southern business hub a dozen years ago to seek his fortune. Memories of the tough experience of queuing all night for a train ticket still remain fresh, he said.

He was inspired to sign up to Shunfengche in 2012 to help Shenzhen-based migrant workers from his hometown of Nanchang, capital of east China's Jiangxi Province, get home for Spring Festival.