车水马龙的英文：
[Literal Meaning]
carriage/stream/horse/dragon
Carriages move on like a stream and horses file past like a long dragon.

[解释]
形容来往车马很多，连续不断的热闹情景。

[Explanation]
heavy traffic on the street

[例子]
以前北京的前门车水马龙，是个非常热闹的地方。

[Example]
In the past, the Qianmen area in Beijing was a busy place with heavy traffic on the streets.

[英文等价词]
like a three-ring circus

The courtyard is thronged with visitors and vehicles.
门前车水马龙。

The city is bustling with life.
城里车水马龙，生气勃勃。

She waited until they were beyond the hustle of the Washington Saturday night traffic.
她一直等到他们远离了华盛顿周六晚上的车水马龙。

The busy road outside the school is a menace.
学校外面那条车水马龙的大道是个危险之地。