Here's ABF pulling a Walmart trailer.
View attachment 482708
There's a thing called the National, or Regional, Truck Driving Championship. Most all trucking companies enter and send drivers. The drivers may not necessarily drive a tractor from their company, or a company trailer attached to their tractor.
My avatar is from, I believe, the 2006 Regional Truck Driving championship, commonly referred to as the Truck Rodeo.