Concepts, Terms and Definitions Related to Surrogate Measures of Safety
The document will define and describe in condensed form the fundamental theoretical concepts of surrogate measures of safety and define indicators (with variations). To the extent possible, the definitions should be kept neutral with respect to the technology or data collection method used as these change rapidly.
Rationale: This document will provide the description of the fundamental concepts of the surrogate measures for safety studies (e.g. safety pyramid, severity of an event, validity & reliability, etc.) and define the practical terms used in this context (e.g. Time-to-Collision, collision course, motion prediction method, etc.). The document will not provide the guidelines or best-practices on how to conduct a surrogate safety study. This is due to the fact that surrogate measures of safety are still in an active phase of research and development. At a later stage, such recommendations may be collected in a separate document.
The purpose is to:
• Outline fundamental concepts,
• Identify and define a common glossary of terms, and
• Provide a clear reference framework for applying surrogate measures of safety.