Signalling 1. What is "Automatic Train Protection" (ATP)? How does it protect train safety? 2. What is "Automatic Train Operation" (ATO)? 3. When travelling on the MTR, we sometimes hear the announcement that there is a signalling failure causing delay. Why does it not affect safety? 4. Why does it not pose any danger when a Train Captain drives the train past a red signal?         *In this FAQs, the illustrations of the explanations require Adobe Flash Player for playback