Old Mines Blamed for Sagging Ohio Highway

State transportation officials believe a section of a main highway in southeast Ohio is sagging because of abandoned coal mine space beneath the road, and they are trying to pinpoint the problem areas that might need to be filled.

Officials with the Ohio Department of Transportation say the problem isn’t an urgent danger, but they’re concerned it eventually could lead to a sinkhole on U.S. Route 33 near Nelsonville in Athens County, specifically on a mile-long stretch just north of the Wayne National Forest headquarters, The Columbus Dispatch reported.

Roads in such situations typically sag gradually and don’t “instantaneously drop,” said Paul Painter, a geologist with the department. “If there is an immediate risk to the public, we would close the lane or detour around.”

The department has started a $225,000 project to locate voids created beneath the road as coal pillars or oak beam supports for the old mine roof collapse over time. Work on that project, which includes three geophysical surveys, will continue into the fall.

“The goal is to fill the mine voids and ensure the safety of the traveling public,” said Andy Moreland, a geotechnical engineer with the department who noticed the problem while driving the highway last summer.

For the nearby Nelsonville bypass that opened last year, about $30 million of the $200 million project cost went toward stabilizing abandoned mines, department spokesman David Rose said.

Records show Ohio has filled four old mines under state roadways since 2008 – two Muskingum County coal mines, one in Vinton County and a gypsum mine in Ottawa County, the newspaper reported.

If gaps go unfilled, the potential sinkholes can be dangerous. An Interstate 70 sinkhole in 1995 swallowed four cars near Cambridge in eastern Ohio, injuring one woman and closing the highway for months. The repairs totaled $3.8 million.