SACRAMENTO, Calif. (AP) Air quality regulators plan to give businesses more time to comply with California’s tough emission standards for off-highway diesel vehicles, such as bulldozers and forklifts.

The California Air Resources Board said Thursday it is offering construction and other businesses more time because of the economic downturn.

The proposed delay would push the start time to 2014 and make it easier for companies to comply. Improvements were originally scheduled to begin in March 2010 for larger fleets with smaller fleets starting later.

California’s 2007 rules require tractors, bulldozers and other types of diesel-powered equipment to be replaced or retrofitted over the next 15 years.

The changes proposed by the air board were approved by the Associated General Contractors of America, a trade group critical of the 2007 regulations.

The board has acknowledged that its staff overestimated pollution created by construction equipment, buses and trucks. It says there are about 200,000 fewer construction vehicles in California than the board initially thought.

The miscalculations led to the proposed changes.

“Our efforts today recognize the severe financial hardships that many businesses are experiencing due to the recession, while also ensuring that we meet our clean air obligations under federal law,” board chairman Mary Nicholas said in a statement.

The construction and truck regulations are meant to improve California’s air quality by targeting particulate matter and nitrogen oxide — pollutants blamed for contributing to respiratory ailments, cardiovascular problems and premature deaths.

Industry trade groups said the changes were a much-needed fix for a business hard hit by the recession.

“It was not easy, but we found a way to protect workers and air quality at the same time,” said Mike Kennedy, general counsel for AGCA.

The board will do a final vote on the extension in December.

Today's top stories

Growing Interest in Construction Careers Among Younger People Means Jobs Filled, Deadlines Met

Larry Young Paving Tackles Grade-Separated Interchange in Texas

Caltrans, Crews Working to Repair Highway Landslides

FIRSTGREEN Industries Launches ROCKEAT Electric Skid Steer Loader

'Tiltrotator Effect' Increases as Energy Consumption Goes Down

VIDEO: Birmingham, Ala., Awarded $14.5M Fed Grant to Revitalize Its 'Black Main Street'

Pettibone Celebrates 75th Anniversary of Cary-Lift

Fay Preps Way for Pittsburgh International Airport Modernization Project