Indian Railways brought 472.3 km of the Kavach Version 4.0 safety system into service in one day, the largest single-day commissioning so far. The stretches lie on the Western, Northern and East Central Railway zones, and take total Kavach coverage past 1,300 km. Kavach is India's indigenously developed Automatic Train Protection system. It stops trains from passing signals at danger (SPAD), guards against over-speeding and improves the reliability of operations on busy, high-density rail corridors.