Integrating Road Safety into NEPA Analysis: A Primer for Safety and Environmental Professionals

Figure 5.1 Nominal and Substantive Safety

Difference between Nominal and Substantive safety. Nominal safety: a design feature or roadway either meets minimum criteria or it does not. Substantive safety is the actual long term or expected safety performance of a roadway; determined by its crash experience measured over a long enough time period to provide a high level of confidence that the observed crash experience is a true representation of the expected safety characteristics of that location or highway.