Across these differences, their food and service are so dependable that the Federal Emergency Management Agency (FEMA) consults an informal “Waffle House Index” to determine the severity of a storm’s impact on a community, where “Red” corresponds to a closed Waffle House, “Yellow” corresponds to a limited menu, and “Green” indicates an open Waffle House.

Source: The Photographer Capturing the South From Waffle House Booths - Gastro Obscura