This report is the second of four volumes concerned with developing safety guidelines and specifications for high-speed guided ground
transportation (HSGGT) collision avoidance and accident survivability. The overall approach taken in this study is to first formulate collision
scenarios to which an HSGGT system may be exposed. Then existing U.S. and foreign rules, regulations, standards, and practices concerned with either preventing the occurrence of a collision, or mitigating the consequences of a collision are reviewed, together with pertinent practices from other forms of transportation, leading to the formulation of guidelines and specifications for collision avoidance and accident survivability.
The volume, addressing collision avoidance, describes the features of signal and train control systems used in existing high-speed rail,
conventional rail and mass transit systems, and other measures to prevent collisions such as prevention of right-of-way intrusions. A description is provided of the interaction between collision avoidance system characteristics and capabilities, and HSGGT system capacity and reliability. Finally, guidelines are developed for collision avoidance systems to be applied to HSGGT systems in the United States.