Thui-soàn tō-hâng(Eng-gí: Dead reckoning, DR) sī chin kó·-chá ê tō·-hâng hong-hoat. Iû ūn-tōng-ha̍k ē-sái chai-iáⁿ, ūi-tì, sok-tō· kap ka-sok-tō· ū bi̍t-chhiat ê koan-hē: