BEIJING - Transcontinental cargo trains, linking China and countries along the Belt and Road routes have become an increasingly important source of wealth.

Such train routes and networks, unified under the China Railway Express brand earlier this year, have expanded quickly after the Silk Road Economic Belt was launched.

With trains running more frequently between China and countries along the Belt and Road routes, loaded with goods and containers, trade volume has increased steadily.

According to industry experts, the transcontinental freight train services have been providing solutions for the international logistics industry and promoting international trade ties and economic development with countries along the route.

Now, railway lines for container trains have been successively opened up by 16 cities in China, heading down to 12 European cities including Duisburg and Hamburg in Germany and Madrid in Spain.

In 2015, China-Europe freight trains made 815 trips, with a year-on-year increase of 165 percent, according to official figures.

One of the train routes is the Yuxinou (Chongqing-Xinjiang-Europe) railway line, which starts in Chongqing and ends in Duisburg, Germany.

The railway was opened in 2011 and has seen a growing number of journeys every year since.

For example, since 2011, the number of scheduled freight trains from China to Duisburg has increased from one to eight trains per week.

Duisburg has become a gateway for Chinese products to European markets.

Another line links China's Chengdu and Suzhou with Poland's Lodz and Warsaw. The freight train service has boosted trade between China and Poland.

Officials in Lodz hoped the city, now with direct train connection with the huge market of China, will grow to become an important hub for the European economy.

Apart from direct connection between China and countries along the Belt and Road routes, transcontinental trains also bring convenience to China's neighbors, such as Japan and South Korea, to help transport their goods from Asia to Europe.

With improved railway infrastructure and new technology, the transcontinental train network provides high efficiency in transcontinental transportation with cheaper cost than airfreight and faster speed than shipping by sea.

For enterprises and businessmen, the intercontinental cargo train network means new markets for their goods and services, thus an important source of wealth. The train network attracts more and more clients while new businesses flourish along the route.

According to the Chinese Ministry of Commerce, trade between China and countries along the Belt and Road routes, stood at some $995 billion in 2015, about a quarter of the national trade volume.

Still, there are huge potential with the expansion of the train network in the future, experts say.