traffic属于物质名词，是不可数名词，均用单数形式。一般是单数，需要用复数的时候只有jam变形，复数：traffic jams堵车，交通阻塞。traffic jams的近义词：heavy traffic例：I hope there will be fewer traffic jams and less pollution in the future.
例句：
There is a traffic jam.
交通阻塞。
The traffic jam interrupted the flow of the cars.
交通阻塞中断了小车的行驶。
There was a traffic jam because two cars were tailgating.
交通堵塞是因为两车追尾。
Oh,there's a traffic jam.
哦，堵车了。
There's another traffic jam on the highway.
公路上又堵车了。
I'm terribly sorry for being late.I was caught in a traffic jam.
很对不起我迟到了，我在路上遇到了塞车。
I was stuck in a traffic jam.
我被困在了交通堵塞的情况中。
We were delayed by a traffic jam on the highway this morning.
今天早上我们给公路上交通阻塞耽搁了。
I was stuck in a traffic jam for an hour yesterday.
昨天我堵车堵了一个小时。
When I went home,I was caught in a traffic jam.
当我回家的时候，我碰上了交通堵塞。
I was caught in a traffic jam.
我碰到了交通堵塞。
But I can't reach there on time due to a traffic jam.
但是由于交通阻塞我不能按时到那儿了。
We were caught in a traffic jam this morning.
今天早晨堵车了。
Sorry I'm late& I got stuck in a traffic jam for half an hour.
对不起我迟到了&我被交通堵塞堵了半个小时。
The traffic jam is breaking up,so we can drive on.
堵车开始疏通了，我们又可以继续开车了。
I was on the highway yesterday in a terrible traffic jam.
我昨天咋高速公路上出了起严重的交通堵塞。