Shanghai: The National Development and Reform Commission (NDRC) has approved a 39.45-billion-yuan ($5.52 billion) plan to build a high-speed passenger rail between Shanghai and Nanjing, the Xinhua News Agency reported Monday.

The new line will be completed in four years and shorten travel along the 300 km route from two hours to 72 minutes, the report said. On completion, the trains will run 24 hours a day at intervals of three minutes during peak hours. the plan is aimed at alleviating traffic on one of the country's busiest lines.

The annual passenger flow of the line is expected to hit 26.35 million by 2020 and 38.44 million by 2030, officials said.

The new rail will transport only passengers, leaving the existing line for the transporting of goods.

The trains will pass 25 cities including Changzhou, Wuxi and Suzhou, integrating the region in a fast-rail network and connecting any two cities in the Yangtze Delta area within two hours, officials said.

The delta area, one of the country's most economically robust, currently contributes about 22 percent of total gross domestic product.

High-speed rail between Shanghai and Hangzhou, Hangzhou and Ningbo, Changzhou and Suzhou are also in the pipeline, officials said.

According to a plan approved by the State Council in 2005, fast trains will shorten a trip between Shanghai and Hangzhou from about 80 minutes to 50 minutes, and a trip between Nanjing and Hangzhou from about four hours to one.

They have all been planned for use by 2020, and will carry more than 400 million passengers a year.

All the fast lines will operate at short intervals, officials said.

"The way they operate will make travel much easier across the region," Chen Jiahai, director of the Institute of National Economy, Shanghai Academy of Social Sciences, told China Daily.

"That will largely change the allocation of residential and business centers," he said.

Chen denied reports that the high-speed rail between Shanghai and Hangzhou will overlap the area covered by the Shanghai and Hangzhou maglev train line.

"The fast lines will have many stops between two destinations, while the maglev line is faster but stops less," he said.