A lowboy trailer is a heavy-duty flatbed designed with two drops in deck height. The first drop is right behind the gooseneck, and the second is in front of the rear wheels. This drops the hauling deck very close to the road surface, often just 18 to 24 inches off the ground. This low profile allows carriers to transport tall equipment without hitting low highway bridges.
Lowboys are the standard choice for hauling construction machinery, like excavators, bulldozers, and cranes. Many lowboys feature a detachable gooseneck (RGN) that unhooks from the trailer frame. The front of the trailer drops to the ground, forming a ramp so tracked machinery can be driven straight onto the deck. Operating these trailers requires careful route planning to avoid high-centering on railroad crossings.