BEIJING -- China would not have achieved its current progress in transport had it not put in place its policies to develop toll expressways, said Weng Mengyong, Deputy Minister of Transport, on Tuesday.

Weng made the comment in response to questions on "unreasonably high" expressway tolls at a press conference held by the Information Office of the State Council, or Cabinet.

Four court officials in central China's Henan province were under investigation after the life sentence they handed down to a farmer for evading a staggering amount of expressway tolls triggered widespread public controversy.

"Because the country did not have sufficient financial capacity, for quite a while we had to borrow from social funds for developing expressways. As a result, we collected tolls to repay the loans," said the deputy minister.

He also admitted that current policies on expressway tolls need further improvement, saying the transport ministry was working with other government agencies on this issue.

"The Ministry of Transport is working to establish a stable and affordable charging system. For transport of important materials, such as fresh agricultural products, tolls will be exempted," he added.

"In the future, we aim to build two expressway systems. One is the toll expressway system which only includes trunk lines and fast tracks, and will be operated and maintained by a relatively low charging standard. The other is a toll-free expressway system which includes all ordinary expressways," he said.

Shi Jianfeng, a farmer from Pingdingshan of Henan province, has made the expressway toll an Internet craze in China.

Shi had allegedly fabricated military driver's licenses and used fake military license plates on his two trucks to evade 3.68 million yuan ($558,000) in expressway tolls.

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The case drew attention and controversy on the Internet, with some saying the life-imprisonment sentence was too harsh and that expressway tolls were unreasonably high.

The intermediate court in Pingdingshan has vowed to retry the case on Friday.

The deputy minister of transport said at Tuesday's press conference that by the end of last year, 17 provinces nationwide had canceled tolls on 90,000-km of second-class expressways, with 1,723 toll gates being removed.

"We aim to cancel tolls on all second-class expressways," he said.