Act of Preferential Treatment for Military Personnel and Their Dependents Article 19

Any active serviceman may be offered at favored rates whenever riding a train, sea vessel, airplane, bus and other transportation means operated by the public agency according to the procedure to be set forth by Ministry of Transportation and Communications (MOTC).
中文原文 軍人及其家屬優待條例第19條
現役軍人乘坐公營之火車、輪船、飛機、公共汽車等交通運輸工具時,得予以減費優待,其辦法由交通部定之。

English translation for reference only; the Chinese text prevails. Not legal advice.