BEIJING -- Three more urban rail sections are expected to open in Beijing this year, the city's acting mayor said Wednesday in a government report.

The total length of metro rails in the Chinese capital will exceed 630 kilometers by the end of the year, Chen Jining said at the opening of the first annual session of the 15th Beijing Municipal People's Congress.

Beijing has been taking measures to ease traffic congestion in the city, including construction of new subway lines.

At the end of 2017, three subway lines, including one for driverless trains, started operation, bringing the total length of metros to 608 kilometers in Beijing.

Beijing now has 22 metro lines.