Both bridges share the exact same random schedule of defect appearances and growth rates, at the same six locations. Only the inspection strategy differs.
- Periodic manual — inspection events happen only at fixed intervals (1 or 2 simulated years). Any defect present right then gets caught and repaired, even if it silently grew to a dangerous size in the months between visits.
- Continuous robotic — a crawler drone re-scans every element on a short, frequent cycle, so a defect is almost always caught within days or weeks of first appearing, long before it grows severe.
- Critical event — counted the moment an unrepaired defect's severity crosses the danger threshold. Periodic manual inspection tends to rack these up because defects have months or years to grow unseen; continuous coverage rarely lets one get that far.