D.C. Circuit Questions EPA’s Efficiency Standards on Trailers

A panel of federal judges appeared unsure Tuesday whether the trailers attached to 18-wheeler trucks qualify as motor vehicles under regulations that set greenhouse gas emissions for tractor-trailers.

The U.S. Court of Appeals for the District of Columbia Circuit heard oral arguments in a challenge by the Truck Trailer Manufacturers Association Inc. to rules setting standards for both the tractor and trailer parts of tractor-trailer vehicles.

The rules set by the Environmental Protection Agency and National Highway Traffic Safety Administration push for the use of technologies such as aerodynamic devices and low rolling resistance tires to reduce emissions. The D.C. ...