Others are truck-and-trailer rigs with varying axle layouts. Each type can legally gross up to 105,500 pounds, much of that payload. Most of its short “pup” trailers have three and four axles ...

Tag, drive, and trailer axle tires don’t have as many lateral forces, so they don’t experience the type of stress that occurs on the front axle. Steer tires don’t have backups, unlike drive ...

Most boxed/flatbed trailers equipped with a six-lug axle and a 15-inch wheel/tire combo are rated at between 3,500 and 6,000 pounds per axle, so that is 7,000 to 12,000 total pounds of load ...

Right now, trailers hooked up to semi trucks are entirely freewheeling -- that is to say, there is no method of producing motive force from the trailer itself, it's just along for the ride.