A: Do you want to come in for some tea?

A: 你要不要进来喝个茶呢?

B: No. I'm running¹ late. I really need to hit the road.

B: 不了。我快迟到了, 得上路了。

"running late" 是快迟到了的意思。

"Hit the road" 的 "hit" 有「去」的意思。好比某人每周去健身房三次, 你就可以说 "He hits the gym² three times a week."。

"I really need to hit the road." 还可以用说成"I really need to get going³."。