China's search-engine giant Baidu on Sunday rolled out its "Apollo Go" Robotaxi service in Beijing, allowing passengers to take the self-driving cabs without reservation.

According to Baidu, passengers can hail the autonomous cabs through its mobile application for free. Forty vehicles have been put into operation so far.

The company's fully automated driving technology was displayed in Baidu World 2020 last month, showing an artificial intelligence (AI) system independently driving a vehicle without any assistance from a driver. 

At the conference, Baidu's Chairman and CEO Robin Li said traffic congestion would be resolved in the next 10 years as AI transforms the transport industry.

Chinese law requires safety drivers for autonomous vehicles to prevent potential accidents.