Air Pollution Control Act Article 38

When a motor vehicle is stationary and idling at designated premises, location or weather conditions, the idling time must comply with the regulations of the central competent authority.The management regulations governing the motor vehicle type, designated premises, location, weather conditions, stationary idling time, and other matters requiring compliance in the preceding paragraph shall be determined by the central competent authority.
中文原文 空氣污染防制法第38條
汽車於一定場所、地點、氣候條件以怠速停車時,其怠速時間應符合中央主管機關之規定。
前項汽車之種類、一定場所、地點、氣候條件與停車怠速時間及其他應遵行事項之辦法,由中央主管機關定之。

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