Public bicycle-rental services have proven an efficient and green solution to ease traffic jams, but the systems must be properly managed to achieve the desired outcomes, experts say.

"Ultimately, whether a public bicycle-sharing system has staying power depends on the frequency of use," says Chen Yanyan, a professor at Beijing University of Technology's Transport Research Center.

"To encourage more people to cycle, either on their own bikes or rental ones, we have to ensure right-of-way and have good infrastructure, such as a proper distribution of rental stations, easy payment methods and good bike lanes."

Chen says Beijing is not cyclist-friendly, for environmental and management reasons. Beijing can get extremely cold and windy in the winter, making cycling difficult.

Liu Fuli, an expert in traffic congestion, agrees. Liu says the bike-sharing system is more promising in the south and in medium and small cities. But it could also function well in a big city like Beijing if well integrated into its existing road and rail system.

However, even when the weather in Beijing is fine, people will not cycle as many bike lanes are occupied by motor vehicles, which is neither safe nor comfortable.

Moreover, many of Beijing's rental stations are near subway stations, but they can also be close to scenic spots and parks.

In comparison, Hangzhou's public bicycle rental service is almost everywhere.

With nearly 70,000 public bicycles scattered across 2,962 service stations around the city, residents can find service stations to rent public bicycles every 300 meters.

Wang Lijuan, a 64-year-old Hangzhou native, says she has been riding the public bicycles for daily morning exercise, shopping and other small errands over the past five years because there is a service station at both entrances of her community.

And it's basically free. There's no charge for the first hour of use. The ride from her home to the Chenghuang Hill near West Lake for morning exercises takes only 35 minutes.

"Since its appearance in 2008, I cannot imagine my life without it," she says.

"We have a car, but what is the purpose of doing exercise if we sit in cars to go everywhere?"

However, even in the city known for its successful public bicycle service, problems exist. It's simply way too popular.

"During the morning and evening rush hours, the difficulty to return the bicycles to nearby service stations is the biggest problem we have now," says Zhang Fumin, who has been general manager of Hangzhou Public Bicycle Transportation Development Co since the system was introduced.

Most service stations do not provide manual services in Hangzhou. With limited parking spots for bicycles, many people face the difficulty of not being able to return them on time.

Qian Li gave up riding public bicycles to work because it was a battle to get a parking spot during rush hours.

"The service station near my company can only provide 20 spots, and they were always occupied when I got to work," she says.

Hangzhou is not alone. Guangzhou, which launched its public bike system in June 2010, also faces a shortage of parking poles.

According to Li Shanshan from the China office of Institute for Transportation and Development Policy, Guangzhou offers 5,500 bikes, but only 2,600 parking poles are available.

Apart from generating revenue to support a bike-sharing system, city governments in China are also advised to upgrade the equipment to reduce maintenance costs.

The bike parking poles in Washington and New York are solar powered, with no need to access underground electricity. The parking poles are in packs of four and each pack is movable so that it's easy to adjust the number and location of these poles at service centers.

"Although the government needs to invest more on the equipment during construction of the system, it can save the maintenance expenditure in the long run. For example, equipping the bikes with better locks will save the administrator money spent on replacing stolen bikes," Li says.