Richard Shoemaker, the project manager for the widening project, said Monday the restrictions probably will begin during the week of March 13.
Work is going on to temporarily widen the south side of the road to allow room for vehicles while the north side is rebuilt, he said.
As the temporary widening is being completed, eastbound traffic could be shifted to the center lane from Edwards Avenue to Spring Valley Drive from 7 a.m. to 4 p.m., according to information on the department's Web site.
Before this phase, about a mile of U.S. 30 west of Quarry Road has been reconstructed, Shoemaker said. This next phase should involve fewer serious interruptions of traffic because most of the storm drain installation for this section has been completed, he said.
"We're in the rip out and put back mode," he said.
At some point during the north-side reconstruction, Shoemaker said Mower and Ragged Edge roads will be closed at U.S. 30. The closures, which Shoemaker said had not yet been scheduled, will occur at separate times for each road and last up to a week.
While the one-lane restrictions are in effect, oversized vehicle loads will be restricted to 10 feet in width.
"It's just too tight to let 14-foot loads through there," Shoemaker said.
Once the north side is rebuilt, reconstruction will begin on the south side of the highway, according to the PennDOT plan.
Also going on is the removal of the asphalt surface from Coldbrook Avenue in Chambersburg east to Burger King, Shoemaker said.
Traffic could be restricted to one lane in each direction in that area while the work is in progress, Shoemaker said.
"That was a new piece we added to the project," he said of the new surface east of Coldbrook.
The project, which involves widening the highway from three to five lanes from west of Exit 16 of Interstate 81 east to the Fayetteville, Pa., area, is scheduled to be completed this fall, according to PennDOT.