An oversized load is freight that’s too large or heavy to move under normal legal limits — too wide, tall, long, or heavy for a standard truck and trailer. Moving one legally requires permits, and often escorts and route or time restrictions.
These loads — construction equipment, machinery, prefab structures — usually ride on open equipment like a flatbed or step deck, or specialized heavy-haul trailers. The extra planning and permitting is why oversized freight typically pays more.