上海驾照美国租车公证？

上海的驾照本身是中英文对照的，是否不要再公证了？
租车条款中如下描述：
An International Driver’s License (IDL) is required if the renter’s national driver’s license is not in Roman alphabet (i.e. Arabic, Greek, Russian or Chinese). International driver's license must be accompanied by the original domestic license of the driver
怎么理解呢？看了些租车的帖子没找到确定的答案，是否这个也有运气在里面？