In 2007, the Air Resources Board (ARB) adopted a regulation to reduce diesel particulate matter (PM) and oxides of nitrogen (NOx) emissions from in-use (existing) off-road heavy-duty diesel vehicles in California. With the March 1, 2010 deadline looming over the construction industry for complying with the off-road regulation, ARB issued a statement yesterday postponing any enforcement actions for noncompliance with the regulation. Because of the faltering economy, reduced construction activity, and associated reduced emissions, "effective immediately, and until further notice, no enforcement action will be taken for noncompliance."