The project of the modernisation of main railway corridors is in progress in Slovakia. The project includes the railway route Nové Mesto nad Váhom – Púchov. This route leads through a rugged country, which, in the Turecký Vrch section, is listed as a protected landscape area. Authors of the design studied several variants. The straightened alignment, and environmental reasons in particular eventually contributed to their preference to the tunnel variant over an up to 40 m deep side-hill cut leading along the entire length of the hill side. The mined double-rail tunnel is 1,775 m long, with the length of the mined section amounting to 1,740 m. The cut-and-cover sections total 35 m. The maximum overburden depth is 100 m. Complicated geological conditions, verified by an exploration gallery, were the reason why the authors of the design selected the New Austrian Tunnelling Method, which allows a flexible response to changes expected in geological conditions. The lining of the mined tunnel consists of two shells with an intermediate waterproofing membrane covering the vault and side walls. The tunnel profile is designed with regard to train aerodynamics, for the speed of 160 km/h (prospectively 200 km/h).