China's high-speed rail sector is facing years of losses due to massive construction costs. However, some lines in eastern China have earned profits recently. The Beijing-Shanghai line earned 6.58 billion yuan in 2015, the most profitable in the world. Five other lines including the Ningbo-Hangzhou line, also started to gain profits last year. However, other lines, especially in western regions, remain stuck in losses. Experts say that it may take at least 16 years for China's high speed railways to pay off their costs.