Pennsylvania has become the latest American state to formally agree to implement auto emissions inspections mandated by the US Environmental Protection Agency to improve air quality.

An agreement on emissions testing was reached yesterday (May 8th), following a compromise which will rely heavily on so-called 'on-board diagnostic' systems that have been installed on all vehicles manufactured since 1996.

The new inspections, which exploit technology that allows a mechanic to attach a cable to a vehicle's on-board computer and download information that can be used to monitor emissions, will be phased in between April and June 2004.

'It is clear that we had to do something with our emissions testing program to cut pollution,' said state Transportation Secretary Allen Biehler.

'This agreement will help us come into compliance and remove the threat of serious sanctions from the federal government,' he explained.

Yesterday's agreement implements a December ruling by the US District Court that ordered the state to put the emissions inspection programs into effect by September in 16 counties that don't currently have them.