Update: As of 3 p.m. Friday, PennDOT said the sinkhole repair was finished and both westbound lanes were open to traffic.
The right westbound lane of Route 30 west of Hallam was expected to remain closed for much of the day Friday as crews work to repair two sinkholes discovered by a Department of Transportation employee on his daily commute.
Westbound traffic near the overpass for School House Road in Hellam Township is restricted to a single lane, but workers were expected to plug the "throats" of the sinkholes and patch the road by late afternoon Friday, said PennDOT spokesman Greg Penny.
A York County PennDOT worker drove over the first sinkhole on his way to work Thursday morning, assuming he felt a bump because he'd hit the edge of the road, Penny said.
But during his 4 p.m. drive home in the opposite direction, he saw motorists driving over and straddling a large hole in the westbound lane, Penny said. The worker called police, who blocked traffic.
It's unsafe to drive over or around a sinkhole, Penny said, because the small hole at the surface is often covering a larger void beneath the surface. The hole could collapse from the weight of a vehicle, causing crashes, he said.
Crews initially found a 2-foot hole, but excavation revealed a second hole had also formed a cavern under the blacktop. Both sinkholes were at least 15 feet deep and between 10 and 12 feet in width, Penny said.
Sinkholes are typically caused by draining water, which can erode softer rocks such as limestone under the surface of the road, Penny said.
The cause of the Route 30 sinkholes was unclear Friday morning.
Crews were planning to plug the "throats," the bottoms of the sinkholes where they drain, with large rocks and concrete, Penny said.
The road will then be backfilled with stone and repaved, he said.
- Staff writer Christina Kauffman can also be reached at email@example.com.