Tollways

However, the highway construction program has also sparked an argument about sections that include tollways.

Nationwide, the length of tollways had reached 163,700 km by the end of last year, accounting for 3.4 percent of the total length of the nation's highways, according to the ministry.

The nation's tollways attracted combined investment of more than 8 trillion yuan from 2010 until the end of last year, the ministry said. However, their combined deficit reached 403 billion yuan last year.

The Jihuang Expressway, a tollway that runs from Jixi to Huangshan city, connects Anhui and Zhejiang. Construction finished in 2014.

Cheng, along with most of his peers who use this expressway, cares more about safety than the toll fees he pays at the various booths.

"It costs 40 yuan for a single trip of about 110 km," he said. "It's not expensive, because the shorter distance means I use less fuel and my vehicle is not getting worn out on the highway compared with the poorly maintained twisting mountain road," he said.

"The toll fee, from my perspective, is necessary for the maintenance and operation of a healthy and convenient highway. I pay the money for a safer trip－it's worth it."

Zhao Jian, a professor of transportation and economics at Beijing Jiaotong University, said levying toll fees is the key to highway maintenance as completed highways and those still being constructed fall under the policy of "Loans for construction, paid back by toll fees."

Approved by the State Council, China's Cabinet, in 1984, the policy helps to attract investment for highway construction from the central and local governments and social groups, which eases the financial burden on the central government.

Under the policy, toll fees are levied by the government to repay the debt used in tollway construction.

"The operation of tollways remains in the red, especially those in Central and West China, which should be emphasized by the government to secure a healthy environment for highway operations," Zhao said.

He added that the preferential policy to allow cars with fewer than seven seats to pass through toll stations free of charge during holidays, the National Day holiday, for example, introduced in 2016 is unreasonable, while more feasible measures should be taken to benefit both drivers and highway operators.

Wang Limei, general secretary of the China Road Transport Association, said the policy should be improved to allow truck and coach drivers free access to highways during holidays.

"The upgrade of the highway network matters greatly to the transport industry," she said.

"But the policy upsets coach and truck drivers as it's only available to small-sized private cars. Coaches offer services to more passengers than small cars, which is more environmentally friendly."

Zhou, from the Shanghai Urban Construction Design and Research Institute, said toll fees could gradually be abolished.

"Traffic capacity in northwestern China is lower than in the east, so toll fees are key to helping the government repay the construction debts," he said.

"However, highways with higher returns－the Shanghai-Nanjing Expressway, for example－can open to the public for free, and we can explore other methods, like levying taxes on car purchasers to balance the operating costs."

Zhou said abolishing toll fees can't be achieved overnight, only gradually. "The Shanghai-Jiading Expressway changed into a toll-free highway in 2012. Though the economic benefits fell in the short term, the move will bring greater benefits to residents, both in Shanghai and Jiading, as their trips will cost less. That will help boost economic development."