It was too late for there to be any subway.

it 指“时间”，不是形式主语，for there to be any subway 不是真正主语，而是不定式复合结构，作结果状语。本句的结构实际为：It was too late for sb. to do sth.

这个句子，是把 there be 存在句，分解为含有逻辑主语的不定式表示，there 相当于sb.。不定式复合结构为结果状语。又如：

It was too late for there to be any open shops. 时间太晚了，不会有营业的商店了。（for there to be...作结果状语）

以下句子，是不定式复合结构作真正主语：

It is important for there to be a free school for the poor children. 给贫困的孩子建一所免费学校太重要了。

In that case it is impossible for there to be an escape from the building. 在那种情况下根本没有从楼里逃出的可能性。

It's normal for there to be a little leftover glue on the drum. 有一点残余的胶留在鼓上是正常的。

It was strange for there to be so few people in the church. 教堂里人这么少真是奇怪。

It was unusual for there to be so few flowers in the park. 公园里只有这么一点花是不同寻常的。

It is natural for there to be a generation gap between the parents and their child. 家长和孩子之间存在代沟是很自然的事情。

It is not uncommon for there to be problems of communication between old and young. 老人与年青人之间存在着沟通问题是很常见的。

It is impossible for there to be any mistakes.不可能有任何错误。

该类型相当于“It is + 形容词（或名词）+ for sb. to do”结构：I t是形式主语，“for there to be”是真实主语，there代替sb.充当不定式的逻辑主语，for there to be看作动词不定式的复合结构。

 【注】网友的例句，it 是指代“时间、日期、距离、天气、情况”等的代词，碰巧跟形式主语 it 重合。