INTELLIGENT VEHICLE-HIGHWAY SYSTEM SAFETY: A DEMONSTRATION SPECIFICATION AND HAZARD ANALYSIS
Anthony Hitchcock · Transportation Research Record Journal of the Transportation Research Board · 1992
A complete specification and fault-tree analysis on one concept for an automated freeway system are described. The example chosen includes a single automated lane on a freeway that also admits manually driven vehicles. Proper execution of all maneuvers is independently verified by infrastructure instruments. There is maximal intelligence within the infrastructure. It is planned to do this again with different starting assumptions. This is only the first example in a set of two or three. Hazards have been specified. A safety criterion has been chosen by way of example. A design has been specified. A fault-tree analysis is also described. This analysis attempts to verify that the design does satisfy all criteria. The example demonstrates that full specification is possible and that design errors (there were four) can be detected by fault-tree analysis. After further development, the technique of full specification and fault-tree analysis can become a basis for safety standards that will apply to both design methods and verification of conformity to safety criteria. The initial assumptions were few and broad. Along with the need to avoid violation of the hazard criteria, they determine a very small set of possible system design structures. There is more than one safe way to design an automated road, but there is not an abundance of options.