Around 7 million journeys are made in metros in Shanghai on a daily basis and passengers rely on escalators in the stations, Huang Xiaolu, director of Shanghai Municipal Bureau of Quality and Technical Supervision said during an online interview via eastday.com.cn, a local news portal.

Quality supervisors looked into all the 287 businesses that maintain elevators and escalators in 2012. Of these 29 were blacklisted and the licenses of 33 were revoked, he said.

People trapped in elevator accidents in Shanghai are rescued within 19 minutes, far ahead of the national average after the municipality required all maintenance companies to have workers on duty around the clock and be in touch with the police department.

With 160,000 elevators and escalators, Shanghai is a global leader, Huang said.