Collaborative tests for a digital Automatic Train Control (ATC) system for high-speed railways in China have been executed jointly by the Railway Technical Research Institute (RTRI), signalling system manufacturers in Japan and China Academy of Railway Science (CARS) for two years since 1996. This digital ATC, based on a developing system for Shinkansen in Japan, is modified as a system for high-speed railways in China, Tests were carried out three times with six track circuits installed on a 9km-long loop track of CARS, and a cab receiver and a brake controller equipped on an SS8 type electric locomotive. We were able to obtain very good results of brake performance by a one-step brake pattern, frame error rates of digital codes from ground to cab including a case where noise of traction current overlaid on the signal and other valuable data.
  In this paper, we describe the specification of the digital ATC in China and the test results on the loop track.