Safety decision
ATC-20 Placard Mapping
The Applied Technology Council's post-disaster building safety placard system, encoded into the classifier's output.
GREEN
ATC-20
No damage→Safe to enter
Building inspected. No restriction on use or occupancy.
Engineer action
Routine inspection only
≥ 0.55, class = no-damage
YELLOW
ATC-20
Minor damage→Restricted use
Entry, occupancy, and lawful use restricted as posted. Repairs required.
Engineer action
Limited entry permitted
≥ 0.55, class = minor-damage · OR any prediction with confidence < 0.55
ORANGE
ATC-20
Major damage→Engineer inspection
Significant structural damage. Requires engineer inspection before any re-occupancy.
Engineer action
No re-entry until engineer signs off
≥ 0.55, class = major-damage
RED
ATC-20
Destroyed→Unsafe — DO NOT enter
Extreme hazard. Do not enter under any circumstances.
Engineer action
Posted unsafe
≥ 0.55, class = destroyed
Decision logic
The classifier predicts one of four damage classes. to_placard() maps that label to a placard — but only if confidence ≥ 0.55. Otherwise the system conservatively escalates to YELLOW for human review.
if confidence < 0.55:
→ YELLOW (engineer review)
elif top_class == "no-damage": → GREEN
elif top_class == "minor-damage": → YELLOW
elif top_class == "major-damage": → ORANGE
else: → RED (destroyed)Why confidence gating?
ATC-20 is a safety document, not a research metric. A wrong RED costs occupant trust; a wrong GREEN can cost lives. When the model is unsure, the placard always defaults to YELLOW so a human engineer makes the call.