In my thesis I showed theoretical basics of horizontal elements for planning railway tracks. I studied their dependents and calculate new horizontal elements to upgrade a chosen section located between Slovenska Bistrica and Pragersko for a higher speed of trains. New track was fitted and adjusted to geographic and urban restrictions and current railway track. It had been planned for speeds up to 90 km/h. New railway track was planned for a higher speed up to 120 km/h. In accordance with Pravilnik o zgornjem ustroju železniških prog (Uradni list RS, št. 92/ 2010) I calculated minimum of curve radius, which is a base for fitting railway track into an area. For tracing of horizontal alignment of track I determined the parameters of curves and transitions curves, calculated cant and proved a high of lateral force.