《吴子·应变》
吴起答： 凡是用战车作战的，阴雨泥泞就停止，天晴地干就行动，要选择高处避开低处行动。要使战车迅速行驶，不论前进或停止，都必须利用道路。
起对曰： 凡用车者，阴湿则停，阳燥则起；贵高贱下，驰其强车；若进若止，必从其道。
Wu Qi replied: When using chariots in combat, if it rains heavily and the roads are muddy, stop; when the weather is clear and the land is dry, move. Choose the high ground to avoid the low ground. When the chariots are moving quickly, use the roads whether advancing or retreating.