The proposed railway line from Guangzhou to Jiaxing will begin construction in March 2017 and be fully operational by the end of 2017.
This translates as:
The proposed railway line from Guangzhou to Jiaxing will begin construction in March 2017 and be fully operational by the end of 2017.
Explanation:
- "launched" is used instead of "start" for a more formal tone.
- "by the end of 2017 year" was chosen to specify that 2017 is part of the year (year).
- "expected" is used in place of "预计" for a more precise and modern phrasing.