TuSimple, a Chinese autonomous truck startup which develops technology for autonomous long-distance freight delivery, has raised $55 million in fresh funds to maintain its edge in the autonomous driving sector.

TuSimple's latest funding round is led by Chinese social media company Sina and others like venture capital funds Composite Capital and Trinity Investment. In August, the company raised $20 million from Sina and other investors including US graphics chip maker Nvidia.

"The new investment will be used to strengthen the company's research and development capabilities and conduct more tests," said Chief Executive Chen Mo.

So far, most of the attention in self-driving technology has been on passenger cars. But the recent debut of Tesla's electric, semi-autonomous truck has helped shift the focus to freight vehicles designed for long-haul shipments.

In China, trucks transported 76 percent of all the freight in the country last year, according a report from Beijing-based Zhiyan Consulting Co. Self-driving vehicles have the ability to reduce accidents, traffic and emissions, as well as increase fuel economy.

TuSimple, founded in 2015 and based in Beijing, aims to improve drivers' working conditions to reduce truck accidents on highways by up to 75 percent. Its ecosystem also decreases fuel waste by as much as 7 percent, according to the company.

Zhao Xiang, a senior analyst at Beijing-based internet consultancy Analysys, said: "Commercial use of autonomous trucks is getting mature. Compared to public roads, the road conditions in industry parks are less complex, which would accelerate the pace of operating driverless trucks."

However, Deng Feng, co-founder of Northern Light Venture Capital, said: "It's difficult to predict the timeline of driverless vehicles' mass production. Some Chinese companies are getting ready to wheel out their vehicles, but the schedule may be delayed due to policy issues rather than technology lag. Another big problem is that hackers may enter the vehicles' operating system.

Deng made the comments on the sidelines of a tech summit organized by media outlet ifeng.com.

Having obtained a license for testing autonomous vehicles on California's public roads, TuSimple ran a self-driving test ride in June. The driverless truck, using camera data primarily to navigate the highway route, cruised successfully between San Diego, California and Yuma, Arizona, which spans 200 miles (322 kilometers).

TuSimple said it could achieve "centimeter-level" accuracy for positioning, even when driving inside a tunnel, and its in-house decision-making machine intelligence makes for safe route navigation.