我遇到了塞车! I was tied up / held up in traffic.
早晚上下班时间,大都市freeway的车速比一般道路还要慢,无数车辆拥上来,造成bumper-to-bumper traffic(车的保险杆相互碰撞的交通状况),这时的车速叫snail-paced traffic(蜗牛步行的交通);这种塞车现象可以叫做traffic jam / traffic congestion;更严重的交通状况称为gridlock(严重塞车,僵局)

A:Sorry,I'm late.
B:I thought you forgot our appointment.
A:No,I didn't.I was just tied up in traffic.
B:You were held up in traffic?But it's not rush hour yet!
A:An accident held up the freeway.It was bumper-to-bumper all the way from downtown.
B:Oh,I see.

参考答案如下:
A:Sorry,I'm late.对不起,我来晚了.
B:I thought you forgot our appointment.我以为你忘了我们的约会呢.
A:No,I didn't.I was just tied up in traffic.不,我没忘.我只是遇到塞车了.
B:You were held up in traffic?But it's not rush hour yet!你遇到塞车?可现在还不是交通尖峰时刻啊!
A:An accident held up the freeway.It was bumper-to-bumper all the way from downtown.一起事故让高速公路的交通几乎中断了.从市区一路下来塞得死死的.
B:Oh,I see.原来如此.