Missing freeway links between provinces are preventing the rapidly expanding network from being world class, a leading transport expert said.

An infrastructure blitz, thanks to the government's 4 trillion yuan ($635 billion) stimulus plan in 2008 to counter the global meltdown, saw the freeway network almost double in size.

Nearly 40,000 km of freeways were built, taking the total length to 84,900 km by the end of 2011, said Li Yaru, deputy chief engineer at the Ministry of Transport's Highway Research Institute.

In terms of length the network is catching up with the United States, which had 92,000 km of freeways by 2010, said Li, a delegate to the 18th National Congress of the Communist Party of China.

But the length, impressive as it is, is not the entire picture, she said.

"Looking at the whole, the freeway network is not fully functional yet because the planned freeways have many missing links between provinces, which reduces efficiency and slows traffic," she said.

According to He Jianzhong, spokesman for the Transport Ministry, the freeway network will eventually consist of 34 lines across the country. By the end of 2011, only seven lines had actually fully taken shape, including Beijing-Harbin and Beijing-Hong Kong-Macao.

Traffic on the other freeways cannot travel the route from start to finish and has to detour using inferior roads due to the missing links between provinces.

The freeway network should resemble a web rather than fish bones but, as Li explained, this is because roads have been built to link major areas, such as cities. These routes have taken priority above the lesser link routes.

"Interprovincial freeways usually come second to expressways between the province's cities," she said.

A typical example is in South China's Guangxi Zhuang autonomous region, where authorities planned to connect with the neighboring four provinces through 17 expressways. But by March, only seven expressways were complete, and four others were still under construction, said Liu Xinwen, vice-chairman of the Standing Committee of the Guangxi People's Congress.

As for the other expressway projects, Guangxi has built its share of the inter-provincial freeways but neighboring provinces have not, Liu said.

The missing links are about 6,100 km long, and 80 percent of them are located in central and western regions, which border provinces that are better off than they are, according to Liu's research.

The loose ends, the fish bones, have caused trouble for logistic companies.

Liu Shuqian, who heads a team of drivers at Guizhou Zhengxiang Logistics, based in Southwest China's Guizhou province, said there used to be a 70-km section missing from the freeway between Guizhou and neighboring Guangxi, which drove up fuel bills and delayed deliveries.

"The missing part was not that long but traffic on that section of road was terrible," he said.

After the 70-km gap was built this year, Liu found that it saves them about an hour for each journey and greatly reduces the fuel bill.

Wu Yue, a professor in logistics at Beijing Wuzi University said: "There is no exact figure for how much the missing sections in the freeway network has affected the logistics industry. But freeways are being built at the fastest rate in the world.

"It takes no more than three days to deliver goods to any part of the country, this would have been unimaginable up until recently."

The Transport Ministry said efforts are being undertaken to fully link up the network.

About 3,000 km of freeway are currently under construction to link up the network, according to He Jianzhong, a spokesman for the ministry.

China hopes to have a freeway network of 108,000 km by 2015, according to the ministry's plan.

Contact the writer at xindingding@chinadaily.com.cn