The curved portion fur each section running safety evaluation interpretation according to the track condition for improving the curved portion passage rate of a vehicle by using the multibody analysis model of the Saemaeul train was carried out. As a result, The excess of cant reaches the bad effect to the running safety in case the radius of curvature is small. In case the radius of curvature was large, we could confirm that the deficiency of cant reached the bad effect to the running safety. In the curved portion, the circular curve section most badly showed the running safety. The deficiency of curve length reaches the bad to the running safety. In the curved portion, the circular curve section most badly showed the running safety. Therefore the track condition(cant, transition curve length, etc) can reach the bad effect to the running safety of a vehicle, the exact design is required.