ERTMS improves railway performance by allowing for reduced headways between trains through more advanced signalling, enabling up to a 40% increase in infrastructure capacity. ERTMS level 2 cab signalling in particular provides continuous speed and signal information to drivers, allowing for higher speeds and even shorter headways than level 1 to further increase capacity. Real-world examples demonstrate significant capacity gains, such as a 15-25% increase on optimized existing lines and up to 242 trains per day on a Swiss ERTMS line with headways under 2 minutes.