Urban management departments in some cities have impounded many cycles after complaints about blocked sidewalks and random, unregulated parking, as Zhou Wenting reports from Shanghai.

As he walked out of a subway station in Shanghai recently, Lin Haowen was delighted to see hundreds of shared bicycles neatly arranged on the sidewalks.

"The hundreds of shared bikes are finally back after disappearing for more than a month. I believe that many commuters like me, who have grown accustomed to riding them, will rejoice," said the 30-year-old computer programmer, who lives 2 kilometers from Xinzhuang Subway Station, the last stop on the western arm of the Shanghai subway system's Line 1.

In April last year, Mobike became the first operator to provide bike-sharing services in Shanghai. The company's arrival meant that Lin could stop squeezing onto buses and was able to ride home from Xinzhuang station every day.

"The advantage of cycling during the rush hour is obvious; it saves time waiting for buses and being caught in traffic jams," the Shanghai native said.

A number of other operators followed in Mobike's wake and began providing bikes in the city, but a few months ago the authorities removed and impounded many of the brightly-colored cycles.

Although a number of reasons were given, the move came primarily because riders were leaving the bikes scattered randomly outside subway stations and office buildings, blocking the sidewalks and forcing pedestrians to walk among traffic on busy roads, and affecting the city's appearance.

"The Shanghai authorities believed the number of shared bikes far outstripped demand so they started removing them from the streets," said an industry insider, who spoke on condition of anonymity.

He said photos of bikes, owned by different companies, stacked in storage spaces have been circulating on the internet. "It's happening in many other cities, too, including Hangzhou (Zhejiang province) and Beijing," he added.

According to statistics released by the Shanghai Bicycle Industry Association, more than 150,000 bikes were removed from the streets between January and August, accounting for nearly 10 percent of the total in the municipality.

The bike-sharing companies said the cycles that were impounded are not returned to the streets directly after being released by the authorities. Instead, performance and safety tests are conducted, along with maintenance and repair, and damaged bikes are scrapped.

Supply exceeds demand

"Each subdistrict is responsible for the management of shared bikes within its jurisdiction, and we cooperate with each one to remove bikes that are causing congestion on the sidewalks near major subway stations. The number of bikes available in some downtown areas far exceeds demand," said an officer with the urban management bureau of Xuhui district, who preferred not to be named.

According to the bike-sharing companies, in districts such as Xuhui and Minhang, the impounded bikes have now been returned to the streets, while in other areas, including Pudong New District, they are still being removed on a daily basis.

"The phenomenon of 'morning and evening tides' of bikes is certainly serious, and often results in the sidewalks near subway stations becoming overcrowded after the morning rush hour," Lin said.

"However, as someone who benefits from this new trend, I hope the government, the companies and users can join together to discover solutions that will minimize the chaos. If not, we don't know when the bikes will disappear again."