China successfully tested an autonomous train operation control system in a subway line in eastern province of Shandong on Sunday, taking a step further toward faster, more convenient and economical transportation.

The technology, known as Train Autonomous Circumambulate System (TACS), was first applied in a test section of Qingdao's Subway Line No. 1. It serves like a "brain" for trains by deeply integrating them with the signaling system.

When equipped, information, such as position, speed and line status, can be directly exchanged among trains via wireless communication, enabling them to make independent judgement and realize autonomous driving, protection and adjustment.

The self-developed TACS highlights train-to-train communication, rather than train-to-ground communication, Fang Shaoxuan, deputy director of Technical Equipment Committee of China Association of Metros, said at an event presenting TACS achievements in Qingdao.

The system features "simple structure, economical operation and maintenance, and intelligent, reliable and safer operation," Fang added.

Through deep integration of train control, traction, network, braking, collision avoidance and other vehicle-mounted control platforms, it makes a technological leap for subways from purely automated driving to intelligent and autonomous operation.

In real practice, the system can greatly shorten the trains' tracking and turn-back interval, increasing the operating efficiency by 15 percent. It can also solve the difficulty of adding trains on the lines with large passenger flow. When facing emergencies like station fires or trackside failures, the system provides greater flexibility for subway operations.

The whole-life cost of a subway can be reduced by 20 percent, thanks to the system optimization and equipment reduction.