A heavy hauler is a rig purpose-built for extreme loads — the kind of weight or size a standard truck and trailer can’t legally or safely carry. These setups often use specialized multi-axle trailers to spread the load across the road.
Because the freight exceeds normal limits, heavy-haul moves typically need permits and one or more escorts, and they may be restricted to certain routes and times. This is the equipment behind most oversized loads — machinery, transformers, and other outsized cargo.