STAA doubles

STAA doubles or double pups are a type of long combination vehicle in the US. They are named for the Surface Transportation Assistance Act (STAA) of 1982. Each trailer is long and wide. The doubles are connected via a dolly. This long combination vehicle is the only combination of trailers allowed nationwide in America. The axle weight allowed is per single axle. STAA double make up less than 3% of the freight trailer fleet in the US.