HARRISBURG — Pennsylvania’s highway department is slapping weight limits on more roads to ensure gas-drilling companies fix the damage caused by their trucks, but says it will exempt local companies that do not use the roads heavily.

Transportation Department spokesman Rich Kirkpatrick said Monday the agency is taking steps to exclude many vehicles over the weight limits from the bonding requirement that’s aimed at the drilling companies.

Kirkpatrick says his agency should be ready with the new permits in about 30 days.

He says the permit will exempt emergency and construction vehicles, school buses or classifications covering residential, commercial or farm vehicles.

The problem began in August when PennDOT posted weight limits on many four-digit state routes in heavy Marcellus Shale drilling areas in northeastern Pennsylvania.