NASHVILLE, Tenn. (AP) The Tennessee Department of Transportation will use a new construction method to repair two Interstate 24 bridges in downtown Nashville, the agency announced April 9.

The process, called accelerated bridge construction technique, will use 277 prefabricated concrete panels to replace the bridge surface decks. The method should reduce repair time because it doesn’t require concrete to be poured and set.

Even with the speedier repair method, TDOT estimated that the section of I-24 along the east side of downtown Nashville will be closed completely for 13 weekends during the spring and summer. The conventional repair method could have closed the lanes for months, TDOT said.

“Trying to do major repairs to the busiest stretch of interstate in Nashville is a huge challenge,” Commissioner John Schroer said in a news release. “Long-term lane closures in the area would have major impacts, not just on I-24, but also on the surrounding areas. Closing the interstate on weekends will save time and avoid delays for thousands of motorists.”

The bridges haven’t had major repairs since they were built in 1961, according to TDOT.

Repairs will begin April 20 and are expected to be finished by Aug. 31. The weekend closures are scheduled to last from 9 p.m. Friday until 5 a.m. Monday.

I-24 traffic will be detoured to Interstates 40 and 65 during the closures.

TDOT will suspend construction and leave I-24 open for several weekends where traffic is expected to be heavy. Those weekends are April 27-29 for the Country Music Marathon, May 25 to 28 for Memorial Day Weekend, June 7 to 10 for CMA Music Festival and Bonnaroo, and June 22 to 24 for a concert at LP Field.

TDOT has used this accelerated bridge construction process once before in 2010 for a bridge on a state Route 24 in Smith County.