The American version: 車車車車
Literally: south – boat – north – horse
Alternately: Going from one place to the next without stop or rest. Always on the go. Wandering restlessly, or traveling busily.
Notes: This compound comes to us from our friend the Huainanzi (淮南子, Enanji or, less commonly, Wainanji). The southern parts of China have a relative plenty of rivers and lakes, so that boats are a preferred method of travel, while the northern parts have a good share of mountains and grasslands, which call for horses; combining the two gives an image of travel that covers the entire territory.
Flipping the order of elements to get 北馬南船 is also possible. This compound is considered to be synonymous with several others that indicate busy rushing about, e.g. 東奔西走.