UPDATE: The section of U.S. 27, closed for repairs Tuesday and Wednesday, was opened Thursday morning after several rounds of testing by TDOT crews.

PREVIOUS STORY: The portion of Highway 27 North at the 12th Street overpass will remain closed overnight until TDOT workers can test the strength of the concrete used to repair a large pothole.

TDOT will test the sample Thursday morning at 6:00.

TDOT spokeswoman Jennifer Flynn says the lane will reopen if engineers determine the concrete meets preferred strength requirements.

Stay with WRCBtv.com for updates to this story.

PREVIOUS STORY: The testing that the Tennessee Department of Transportation performed on the concrete repair of U.S. 27 Wednesday was "not encouraging" according to TDOT spokesperson Jennifer Flynn.   

A second test sample will be taken about 9:00pm Wednesday night. If that test fails, TDOT will take another test sample at 6:00am Thursday morning. 

TDOT hopes to open the outside northbound lane of U.S. 27 before the morning rush hour Thursday.

 PREVIOUS STORY: TDOT crews have been working since 3:00am Wednesday to repair the large pothole on the 12th Street overpass bridge near the MLK Blvd. exit ramp on U.S. 27 North.  

The deteriorated concrete has been removed and forms were put in place. New concrete was poured and covered at about 9:00am Wednesday.

Jennifer Flynn with TDOT said the area that required repair was about 4’x12’ and was the full depth of the overpass deck. Another smaller section nearby, about 2' x 2' was also repaired

Crews used quick-curing concrete and will perform tests about 3:00pm after the patch has time to properly set.  

If the concrete tests are successful, the closed lane will be re-opened to traffic.

It's the same area that's been a trouble spot for holes in the past.

"It will be replaced as a part of a project that's going on right now. what we're doing right now is trying to keep it basically in as good as shape as we can until it is torn down and replaced,” Flynn said.

With US-27 already under construction, many drivers like Jessica McCosh worried the extra closures could have made for a busier commute.

"I avoided the area and took the first market street exit to get into town, thankfully I was coming into town a little bit earlier for a morning project and was able to avoid that area,” McCosh said.

Others weren't so lucky.

 "Several of my colleagues did get stuck in traffic because they came later in the morning.” McCosh added.

Right now it's not clear what caused the pothole, though TDOT said it's that time of year when drivers need to be extra cautious on the road.

"This is definitely prime time for potholes and the reason being there's a lot of change in condition,” Flynn said.

TDOT said this bridge where this pothole formed is a part of the long term US-27 widening project that slated to be completed in 2019. 

PREVIOUS STORY: A large pothole forced Tennessee Department of Transportation officials to close a portion of Highway 27 and an exit ramp Wednesday.

TDOT spokeswoman Jennifer Flynn the pothole formed on the portion of Highway 27 North at the 12th Street overpass in the outside lane.

Flynn says the size of the pothole forced TDOT to close the outside lane and exit ramp to MLK Boulevard until repairs are made.

TDOT workers started repairs Tuesday night, but Flynn says it is very likely that the lane and exit ramp will remain closed until Wednesday evening. 

Drivers who normally use the MLK Boulevard ramp will need to use the 4th Street exit ramp.

Stay with WRCBtv.com for updates to this story.