Maximum speed of the train could not exceed over 160km/h with R-bar system in the underground type tunnel structure. By the research to overcome this speed limit, maximum speed has reached up to 200~250km/h recently by new R-bar system. It is under discussion to construct Metro Express Line between Gyonggido and Seoul which requires maximum speed 180km/h~230km/h. New R-bar is an optimal system to achieve the speed improvement in this line. This study shows application of the high speed R-bar system in the underground tunnel section.