交通 (jiāotōng) means "traffic" or "transportation" and covers all forms of transit and movement of vehicles. It combines 交 (to cross/exchange) and 通 (to pass through). Common phrases include 交通中断 (traffic interrupted) and 交通工具 (means of transportation).
今天早上交通特别堵,我迟到了。
Jīntiān zǎoshang jiāotōng tèbié dǔ, wǒ chídào le.
The traffic was especially bad this morning, so I was late.
这座城市的交通越来越方便了。
Zhè zuò chéngshì de jiāotōng yuè lái yuè fāngbiàn le.
The transportation in this city is becoming more and more convenient.
坐地铁是最快的交通方式。
Zuò dìtiě shì zuì kuài de jiāotōng fāngshì.
Taking the subway is the fastest mode of transportation.