Beijing subway has become one of the busiest in the world in terms of daily passenger journeys, Beijing Subway Company (BSC) said Wednesday.

On Friday, subway passenger flow exceeded 10.27 million trips, according to BSC's Sina microblog, the first time the number of daily journeys has topped 10 million. The previous record was 8.39 million trips set in April, 2012.

With the opening of Phase 1 of Line 14, the interchange between lines 9 and 1, and the completion of Line 10, expected later this year, passenger flows of 10 million-plus could become normal, the Legal Mirror reported Wednesday.

Commuters said they now fear taking the subway could be as slow and congested as driving on the roads.

A female resident surnamed Song, 30, said that she now takes Line 10 every day from Guomao Subway Station to Zhichunlu Subway Station. For Song, the Line 10 extension, which opened in December 2012, was a disaster.

"I need to wait for about five trains to get on at Guomao during rush hours, which makes me anxious," she said, "but I still have to use the subway because of the severe traffic jams on the road."

Line 10 has become by far the busiest of the current 16 lines in the city. BSC plans to add more trains and reduce the waiting time for trains on Line 10 from 2 minutes 30 seconds to 2 minutes, the Beijing Evening News reported Wednesday.

Another resident surnamed Zhao, 29, said he might consider riding a bike in future if the subway gets more crowded.

"Although Beijing subway is quite advanced, and I can travel cheaply and on time, given the high passenger flow, cycling might be a good alternative to save time on queuing," said Zhao.

An anonymous employee from the administration office of BSC said that there were several reasons for the high passenger flows on Friday.

"Beijing Guoan played a football match that day, which added to the regular Friday peak time traffic," she said. 

Meng Bin, professor of urban planning at Beijing Union University, said that the intensity of subway use is because passengers have become more reliant on this form of transportation.

"But it is unknown whether the problem of heavy passenger flows can be solved through building more lines and adding more stations. I think building new lines and stations will increase the passenger numbers but this may decrease the density of passengers at every station and on every line," said Meng.