A network of high-speed lines, linking secondary routes to major ones, is on track to be completed by 2015, an official said a day before the first train departs on the world's longest high-speed line on Wednesday.

The 2,298-km line will connect Beijing and Guangzhou, capital of Guangdong province. Trains will hurtle along the track at 300 km per hour.

The country's high-speed railway network will reach 50,000 km by 2020, with four north-south and four east-west main lines as the major routes.