SAFETY ANALYSIS OF ARES

The approach to accessing Advanced Railroad Electronics System (ARES) safety is to compare the actual accident rate attributable to failures in the current train control systems to the predicted accident rate under full ARES operation. The current accident rate data was extracted from Burlington Northern (BN) Railroad accident statistics. The accident rate for ARES was predicted by modeling the effects of hardware failures and human errors within ARES. For the current control systems, the average number of control system related accidents on all BN lines is about 50 per year. The predicted rate if the full ARES were employed on these lines is 0.5 accidents per year. Therefore, ARES is about two orders of magnitude safer with respect to control system related accidents. The reason for this is that the ARES employs highly reliable computerized information cross-checks and clearance enforcement mecha nisms that do not exist in the current system.