WASHINGTON, — Testing highway diesel truck emissions under 2007 standards will be more accurate, less expensive, and more effective under a new in-use testing program announced by the Environmental Protection Agency.

The agency says it will use state-of-the-art technology to ensure its stringent emission standards are met under real-world driving conditions. The program is the result of unprecedented cooperation involving EPA, the California Air Resource Board (ARB), and diesel engine manufacturers.

While vehicles from a selected sample of typical trucks and buses are in operation, portable measuring devices attached to the engine will assess exhaust emissions of hydrocarbons, carbon monoxide, nitrogen oxides, and particulate matter, the EPA says.

Previously, testing diesel engine emissions required removal of the engine from the truck and testing in laboratories. These former testing procedures were more cumbersome, less accurate and more expensive, EPA admits.

EPA is also revising the test procedures to reflect current state-of-the-art portable emission measurement technology. This rule also creates unified testing requirements for all engines that will streamline laboratory efforts for EPA and industry.

The new program begins this month with a pilot program that calls on manufacturers to recruit volunteer test vehicles from fleets or individual owners. It will expand across the U.S. 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,” said EPA Assistant Administrator for Air and Radiation Jeff Holmstead in a press release. “This collaborative effort with engine manufacturers will help ensure that diesel trucks run cleaner for as long as they are on our roads.”