The Alabama Department of Transportation is contemplating permanently moving the closed section of U.S. 231 in Morgan County away from the substantial damage beneath the highway that has led to its indefinite closure.

In essence, ALDOT would be rebuilding a section of the four-lane highway on the side of Brindlee Mountain in a new location as a better option to repairing the road where it currently runs. ALDOT clarified Thursday night that option would move the northbound lanes to the right and then building new southbound lanes immediately adjacent to the northbound lanes.

Related: No quick solution expected to repair closed Highway 231

Consideration of such a dramatic solution underscores the seriousness of the deteriorating ground beneath the highway, which the ongoing study of the site has revealed stabilization issues as much as 70 feet below the surface.

In an interview Tuesday with AL.com, ALDOT engineer Curtis Vincent repeatedly described the “slide” of the ground to be “substantial.” It also is more than just topsoil – Vincent said it also includes rocks beneath the surface.

Vincent declined to estimate how much longer U.S. 231 would be closed in Morgan County, saying a more definitive timetable would be available once ALDOT determines its corrective course of action. Vincent said that decision should come later this week.

The closed section of the road is about 7 miles south of Huntsville and the detour has created traffic headaches for commuters. The four-lane highway has been replaced by a series of two-lane roads and the installation of temporary traffic lights at two intersections on Alabama Highway 36.

The problem began about three weeks ago as cracks appeared in the southbound lanes and quickly worsened as well as developing on the northbound lanes on the side of the mountain. After initially attempting repairs, ALDOT closed the road as the cracks grew bigger along about 1,000 feet of roadway in both directions.

Related: ‘Extended closure’ expected for Highway 231 south of Huntsville

Since then, the highway department has been studying the problem.

"In this case, it's actually rock and according to the geologists, there's been movement there on the side of the mountain for years," Vincent said. "It hasn't been noticeable in the roadway up until this major event. Our challenge now is to figure out how to fix it, how to prevent that mass of rock and soil and roadway from moving again."

Meetings are scheduled for Wednesday to work to identifying a solution, Vincent said.

"As you can imagine, there are several options out there on the table that are being considered," he said. "There's different types of repairs being considered."

While making the most cost-effective decision is a factor, Vincent declined to speculate on how much the solution would cost.

"Do you move all four lanes further up the mountain? If you do, you have to make connections, you’ve got to make connections back down to the existing road in both directions. So you have to consider that cost. If you make the repairs and leave the roadways where they are, there's additional things that come into play there. You can't just look at one piece and say this piece is less expensive. You've got to look at the overall, entire fix."

Vincent explained how the depth of the problem beneath the road is a challenge to resolve.

"It appears what I'll call a slip plain – the area between solid rock and the colluvial rock on top is about 65 feet below the surface," he said. "If you can picture the magnitude of what we're talking about, 1,000 feet of roadway, a depth of 65 feet below the surface, a mixture of soil, rock and water has moved.

“You have to say how do you repair it? You’ve got to put something back that’s solid, something that’s anchored, something that will never move again. In order to do that, you have to have some means of tying down into solid limestone at a depth of more than 65 to 70 feet deep.”

Updated today, March 4, 2020, at 10:08 p.m. with clarification from ALDOT on the option to build a new road at the site of the issue.