The interior of the modified Raeton. [Photo courtesy of Chongqing Daily]

Bad weathers like heavy rains can also add to the difficulties, so although it's a driverless test, drivers are still needed and seated in the car.

For the road test, two licensed drivers of unmanned cars shift every two hours to keep eyes on a car on the way to ensure the safety.

Zhu Huarong, president of Changan Automobile Co Ltd, attends a ceremony before the departure of the driverless cars, on April 12, 2016. [Photo courtesy of Chongqing Daily]

"Our self-driving technique is still some way from driverless of a true sense, but we are keeping transplanting mature techniques to mass-produced vehicles after developing, experimenting, and road testing," said Kong Zhouwei, an engineer with Changan and a test driver with the long-distance road test.

"Safety must be a priority and that cooperation is essential to furthering the technology," said Xin Guobin, vice-minister of the Ministry of Industry and Information Technology, adding that the ministry is working on a standardization system for self-driving cars.