The road is wide enough for five trucks through at the same time.

这个句子，口语或非正式英语可以说，但是，正式的书面语是不妥的。

首先，through只有介词、副词、形容词这几个词性，没有动词的词性。此外，假设它是动词，那么在本句中的用法也不当，它不可能以动词原形的面貌出现，而应以不定式形式。从through在此的作用看，应属副词。但是，副词需要跟适当的动词搭配才成立，如：go through, pass through, run through等。该句漏掉了动词，正确的英语表述应为：

The road is wide enough for five trucks to go through at the same time.

The road is wide enough for five trucks to pass through at the same time.

The road is wide enough for five trucks to run through at the same time.