The U.S. Environmental Protection Agency on Friday announced a new in-use testing program for diesel truck and bus emissions.

Prior to this program, an engine had to be removed from the truck for testing in a laboratory. The testing procedures were cumbersome, less accurate and more expensive.
In the new program, vehicles from a selected sample of trucks and buses are assessed while in operation. Portable measuring devices attached to the engine will assess exhaust emissions of hydrocarbons, carbon monoxide, nitrogen oxides, and particulate matter.
According to the EPA, state-of-the-art technology will ensure EPA's stringent emission standards are met under real-world driving conditions and deliver increased public health benefits.
In a press release, the agency said the new program results from cooperation involving EPA, the California Air Resource Board and diesel engine manufacturers. The program involves testing engines while they are in service and begins this month. A pilot program calls on manufacturers to recruit volunteer test vehicles from fleets or individual owners. The program will expand nationwide starting with 2007 model year diesel trucks.
"This program is a dramatic addition to the EPA's Clean Diesel Campaign and will result in healthier air for all Americans. This collaborative effort with engine manufacturers will help ensure that diesel trucks run cleaner for as long as they are on our roads," said EPA Assistant Administrator for Air and Radiation Jeff Holmstead.
For more information on the testing program, go to www.epa.gov/otaq/hd-hwy.htm#inuse.