The Federal Highway Administration recently issued final rules related to truck size and weight regulations that include guidance regarding the new 400-pound weight exception for trucks equipped with an auxiliary power unit.
A provision of the Energy Policy Act of 2005 increased federal weight limits to allow for APUs. In a Feb. 20 Federal Register notice, FHWA said it will allow up to 400 pounds in axle, tandem, gross or bridge weight formula (an axle weight calculation), or the weight of the APU unit, whichever is less.
FHWA acknowledged the concerns of enforcement agencies about APU weight certification requirements, but it concluded that trucks equipped with an APU must carry a written certification of the APU’s weight. FHWA also determined that it only will consider the APU’s empty weight, not the weight including fuel.
To view the final rule as a pdf document, click here.