For operators overseeing steep cuttings, tunnels and locations with a known rockfall history, passive protection is the right foundation — and for good reason. Warning: But passive protection has a blind spot: operational visibility. Why Seconds Matter in a Rockfall Alarm SystemOnce in place, sensors do what passive protection alone cannot: actively report the structure’s condition in real time. 2010 — Operating in the Gotthard corridor, Switzerland — over a decade of continuous operationFrom Passive Protection to Intelligent InfrastructureBarriers, nets and fences are increasingly becoming active safety assets rather than passive infrastructure. This is not a choice between passive rockfall protection and active visibility.