China's railway investment increased in the first half year and national railway investment is expected to hit a new high in 2017, authorities said Wednesday.

In H1, fixed asset investment on railways hit 312.5 billion yuan (about 45 billion U.S. dollars), up 1.9 percent year on year, according to the China Railway Corporation (CRC).

"Investment is expected to hit a new high for the whole year, as construction in the second half year will rise as new projects get underway," said Wang Mengshu of the China Academy of Engineering.

Scheduled progress has been made in 27 major projects, including the Beijing-Shenyang passenger line and Hangzhou-Huangshan high-speed line, the CRC said.

More lines will be started in the second half, including a high-speed line between Anqing and Jiujiang and a line between Huanggang and Huangmei in eastern and southern provinces.

"Completing an investment of 800 billion yuan is out of question," said Wang, given that the third and fourth quarters usually see the approval of a larger number of projects.

Wang believes total investment this year will surpass last year's 801.5 billion yuan, as both the central and local governments are active in the field.