Related: Live like a hermit

More than 100 delegations from home and abroad have come to see the "Guangzhou Mode of BRT" and many have decided to reproduce the model. Fjellstrom is now a frequent flier, giving presentations all over the world on Guangzhou's BRT.

His team is now working on the BRT in Lanzhou, Gansu province, which is scheduled to open later this year. It has also signed a contract with the Malaysian government to help with the BRT project in Kuala Lumpur.

"Guangzhou's BRT is a successful project and it has brought my colleagues and me many job opportunities. We can help improve local public transportation, which is our dream," Fjellstrom says.

Before the Guangzhou project, Fjellstrom had job-hopped around Asia. But he really wanted to focus on one project, working from start to finish. He chose China for his career breakthrough.

"The whole world is interested in China. Everybody is looking at China, so it's a good choice if we want to encourage cities to improve public transport. They see China doing well and will want to catch up with it," Fjellstrom explains.

"And the governments are quite powerful in China, which means if the governments decide to do a big project, they can really implement it," he adds.

To recognize Fjellstrom's contributions, he was named one of Guangzhou's top 10 outstanding young people in June - the first foreigner to get into the list.

Fjellstrom is thrilled to be recognized as part of Guangzhou, where he has settled. He is married to a local engineer and they have a 2-year-old son.

"I can't speak Cantonese. I am a newcomer. But I think many people in Guangzhou are immigrants," he says. "For example, people in my office are from all over the country. And if you go to Xiaobei Road, you may meet more Africans than Chinese. I like that about Guangzhou."

In Fjellstrom's opinion, the best way to learn about the city is on two feet.

He has even made his own walking maps, a series that includes four editions of 28 walking routes through six districts. Each walking route is illustrated by a navigation map which follows and points out places of interests with pictures and descriptions.

"I hope my map can allow tourists to discover, and local citizens to rediscover the city. What the map includes is not necessarily in the tourist guides, but things authentic about the city's living culture," Fjellstrom explains. The Guangzhou government intends to print his maps and hand them out.

Duan Xiaomei, Fjellstrom's wife, says she was attracted by her husband's heartfelt passion about his job.

"Karl wants to promote the technology of developing sustainable transportation and encourage as many people as possible to adopt the lifestyle of taking buses, cycling and walking," she says.

She tells us that apart from eating, sleeping and playing with his son, Fjellstrom devotes all his waking moments managing the websites he set up to share his maps of bus routes and walking tours.

In his opinion, it is key that China starts focusing on developing sustainable transport and setting a good example for the rest of the world. "In many cities in the world, public transport declined and cars increased because they did not have good transportation policies. In China, there are still many people taking buses, riding bicycles and walking," he says.

"But things change fast. Car ownership is rapidly increasing in all Chinese cities, and many policies now give priority to car owners. We need more projects to sustain buses, bikes and walking.

"Guangzhou's BRT is like my child. I'll stick to China's one child policy but for the BRT, we definitely need more than one," Fjellstrom grins.

Shu Meng contributed to the story.