But variables like pedestrians in crosswalks, large crowds and vehicle wrecks can throw a carefully designed system out of whack, leading to annoying and pollution-causing traffic jams.

但是，正在穿越人行横道的路人、摩肩接踵的人群以及道路上抛锚的事故车等不确定因素都可能让一套精心设计的系统崩溃失常，导致恼人而又产生污染的交通拥堵。

youdao

Americans are shrugging off the snowstorms, heavy rain and fog that are causing flight delays and traffic jams.

美国民众对暴风雪不以为然，而暴雨和大雾天气则导致航班延迟，交通拥堵。

youdao

Sometimes visibility drops to less than 1 kilometer, causing serious traffic jams, flight delays and highway closures.

有时，能见度下降到1千米以下，引发了严重的交通阻塞，航班延误和公路关闭。

youdao

Rather than making their users more mobile, some laptops are merely weighing them down--and causing traffic jams in airport security.

FORBES: Ditch Your Laptop For These Gadgets

Iraqi security forces are on high alert and have established more checkpoints in and around the capital, causing massive traffic jams during rush hour.

CNN: SHARE THIS

Roadworks are causing "traffic jams from hell" in a Surrey town.

BBC: Guildford roadworks causing 'jams from hell'