Beijing opened as many as five subway lines on Dec. 30.

Beijing opened as many as five subway lines on Dec. 30. And it's not only the capital city expanding its public transportation. The latest report by China International Capital Corporation shows that up to 36 cities in China have submitted their plans for subway construction, the 21st Century Business Herald reported.

Competition is fierce among Chinese cities over subway construction, according to Wang Mengshu, a member of the Chinese Academy of Engineering. They want the miles of the subway line to be the longest and the construction time to be the shortest, but hastening construction could also bring hidden safety dangers, Wang said.

In some medium-sized cities, the roads are enough for the traffic, and subway lines are not even necessary. It would be a waste to build subway lines.

Currently, constructing a kilometer of subway line in China costs 400 to 500 million yuan on average, and some could even reach 700 million yuan. The high cost of maintaining the subway requires huge governmental investment and high ticket fares that the public can hardly afford, and those factors could doom subway operation.

In some cities, the local governments have to pay as much or more than 1,000 million yuan in subsidies every year to keep the subway running.