It started as a social media quest for dumplings, but ended with thousands of cyclists bringing traffic gridlock between two cities in central China.

What should have been a boost to the ancient city of Kaifeng’s economy backfired when the trend went viral – tens of thousands on rented bikes cycled through the night from nearby Zhenghou for breakfast.

A six-lane expressway between the two cities quickly filled with cyclists. Police used loudspeakers to tell them to leave and bike rental firms warned they would remotely lock bikes taken out of Zhengzhou.

The event is part of a trend of young Chinese people travelling cheaply at a time when the economy is faltering and job prospects are scarce.

The trend was started by four university students who cycled the 50km (30 miles) from Zhengzhou to Kaifeng in June to try guantangbao, a type of soup dumpling.

“You only have one youth, you have to try a spontaneous trip with your friends,” one of four told local media.

That message struck a chord with other young people in the city of 12.6 million people, at a time when many in China complain of burnout from an overly-competitive job market.

A social media trend called “Night Ride to Kaifeng” was born. State media initially praised the trend as a demonstration of young people’s “passion”.

Local government saw it as a opportunity to recreate the instant fame that the town of Zibo enjoyed last year because of its barbecues.

Before Friday night’s gridlock Kaifeng officials even announced special discounts and events for college students. They also put in place additional traffic control measures to protect the cyclists.

Ms Li, 27, rode a motorbike to Kaifeng along with the students on Friday night. She said she saw a post about the trend and decided to join and “live like a young person for once”.

“Everyone was beaming with energy and interacting with people around them. It was like back to my college days,” she told the BBC.

There was heavy police presence all the way, she said.

“You could see ambulances and traffic police cars on both sides of the roads quite often, and there were also drones flying in the sky to monitor the traffic,” she said.

But the happy mood soon changed. The roads in Zhengzhou started being overwhelmed by the thousands of bikes.

Pictures circulating online showed serious congestion on the main roads from Zhengzhou to Kaifeng. One witness told local media Jimu News that his drive on the same route, which usually took one hour, took three.

Some riders shared on social media that they were forced to get off their bikes and push their way through the crowd.

There was no official estimate of the number of bicycles on the road on Friday night. But reports on social media suggest the number ranged from 100,000 to 200,000.

Many of those who made it to Kaifeng didn’t end up having a good time either.

One viral post from a student, who rode more than seven hours, said they couldn’t get a taxi or a hotel room as the demand was overwhelmingly high.

“I really regret going. As I sat in a restaurant eating my meal, I heard the owner criticising college students for having nothing to do… I’m really sorry for affecting the people in Kaifeng,” the student said on social media platform Xiaohongshu.

As the gridlock worsened, three major hire bike platforms in China issued a joint statement urging students to use trains or buses for long distance travel and avoid using bikes at night for safety reasons.

By Saturday afternoon, the companies had started charging a fee for those who ride to a different city.

Multiple posts suggest some universities in Zhengzhou have now asked students to return to their dormitories and imposed restrictions on them leaving the campus.

Some social media users criticised the cyclists for “irresponsible” behaviour such as littering.

Traffic police in both Zhengzhou and Kaifeng closed off some of the main cycling lanes between the two cities on Saturday and Sunday.

It is also not surprising to see authorities in the two cities pushing back as Chinese authorities have always cracked down on big gatherings to ensure stability.

Last month, police in Shanghai silenced celebrations for Halloween over fears the revelries might turn into platforms for dissent.

But Ms Li thinks these events and trends such as the Night Ride to Kaifeng will continue to appeal to young Chinese people.

“People are so stressed these days, so these events are a good thing. Because happiness is infectious.”