▲在 rush hour 前面用介词 in 或 at 都可以，意思也差不多，都表示“交通高峰时段”“交通拥挤的时候”“上下班交通高峰期”，但要注意两者的搭配是不同的：

1. 用介词 at 时，通常不用冠词（即用零冠词）。如：

I had to drive eight miles at rush hour. 我得在交通高峰时间行车8英里。

I’m anxious to avoid the motorway at rush hour. 在交通高峰时段，我对高速公路唯恐避之不及。

Even with a change of trains, the subway is quicker than a cab at rush hour. 高峰时段地铁即使要转车也比出租车快。

A car breaking down at rush hour could cause gridlock across half the city. 在交通高峰时间，一辆车抛锚就可能使半个城市都陷入交通瘫痪。

The bomb contained a timing device set to make it go off at rush hour. 炸弹有一个定时装置，预设在交通高峰时间引爆。

2. 用介词 in 时，通常要用定冠词。如：

The traffic in the city is chaotic in the rush hour. 在上下班高峰时间，城市的交通混乱不堪。

On the tube in the rush hour the passengers are packed like sardines. 交通高峰期的地铁里，乘客挤得像沙丁鱼罐头一样。

You need the luck of the devil to get a seat on the train in the rush hour. 上下班交通高峰期，你得非常走运才能在火车上找到空位。

▲除了用介词 in, at 外，有时也用介词 during，此时也通常用定冠词，与 during the rush hour 与 in the rush hour 同义，但更强调“期间”。如：

They run extra trains during the rush hour. 他们在车流高峰期加开了列车。

There ought to be more buses during the rush hour. 高峰期间应该多开几趟公共汽车。

I purposely avoid making train journeys during the rush hour. 我有意避开在巅峰时段搭火车。

During the rush hour the journey may take up to twice as long. 这段路在交通拥挤的时候可能得花两倍的时间。

Traffic slows to a crawl (= goes so slowly it almost stops) during rush hour. 上下班交通高峰期，车辆行驶速度跟蜗牛似的。

▲有时rush hour 前有 morning, evening 等词修饰。如：

I got caught in the morning rush hour. 我在早上的交通高峰时间遇上了塞车。

During the evening rush hour it was often solid with vehicles. 在交通的晚高峰时段，这里通常被车辆堵得水泄不通。

▲当然例外的情况偶尔也有（不算普通，宜慎用）：

The explosive device was timed to go off at the rush hour.

During rush hour, downtown streets are clogged with commuters.  在交通高峰期，闹市区的街道挤满了上下班的人。