The similarities and differences between low-bed semi-trailer and flatbed semi-trailer are that the lengths of the two types of vehicles are generally 9 meters, 9.5 meters, 10 meters, 11.5 meters, 12 meters, and 13 meters, but in terms of width, low-bed semi-trailer types are 2.8 meters, 2.9 meters, and 3 meters wide, while flatbed semi-trailers are only 2.5 and 2.55 meters wide.