"As with many infrastructure projects in China, including the high-speed rail network above ground, questions abound about the wisdom and potential wastefulness of such ambitions. Many of the underground systems are needed, but some are being built in cities that are too small to justify the exorbitant expense. By some estimates the total bill could approach $1 trillion, not including the cost of operation."
"Zhao Jian of Beijing Jiaotong University reckons that metros in fewer than 20 of the 38 designated cities make sense. He says that perhaps ten of those could be replaced with cheaper light rail, which runs above ground."