Precursor Systems Analyses of Automated Highway Systems

Résumé du livre

The objective of this activity area is to "identify, consolidate, and discuss the major technical, design, and implementation issues and risks to be resolved for providing AHS users with a collision-free driving environment under normal operating conditions, including entry to and exit from the system." Normal operating conditions are taken to be all conditions, (specifically including threat conditions) that may occur while the AHS is operating in the absence of system malfunction. In other words, if all possible conditions that have unsafe implications are considered, only a portion of them are allocated to AHS malfunctions. The remainder are allocated to "normal operating conditions." To identify safety issues and asses their significance, formal system safety analysis procedures were used in conjunction with each system concept. Issues associated with critical safety performance assumptions were identified for the safety goals for which the concept has accepted control responsibility. These were expanded to include issues arising from threats not allocated to or accepted by system control. Formal evaluation and documentation procedures (parallel to those in MIL-STD 882B) were used not only to document the relative insignificance of an issue, but also to provide the beginnings of a tracking procedure to ensure satisfactory resolution of significant remaining issues in later work.