For high-speed lines (≥ 250 km/h), TSI-INF specifies a minimum curve radius of 6,000 m on main running lines 1. RATO-2 §4.3 additionally requires that cant deficiency must not exceed 130 mm for passenger rolling stock 2, while freight-only lines may apply a reduced minimum of 300 m on secondary tracks with appropriate speed restrictions 3. The ruling gradient combined with curve correction must also be applied when both constraints occur simultaneously 2.