The Texas Department of Transportation will close all lanes of I-35 at Williams Drive on the last two Friday and Saturday nights of January as crews demolish and remove a portion of the Williams Drive bridge.

The closures will take place from 9 p.m.-9 a.m. on Jan. 20-21 and Jan. 27-28.

During this time, northbound traffic on I-35 will detour to the frontage road at the Williams exit and re-enter the highway north of Northwest Boulevard. Likewise, southbound traffic will exit at Williams and re-enter north of Hwy. 29, according to a TxDOT release.

Additionally, the Williams bridge will be closed at the same time. Eastbound traffic crossing over I-35 on Williams will be detoured to the southbound I-35 frontage road where they will make a U-turn at Hwy. 29. Similarly, westbound traffic on Williams will use the northbound I-35 frontage road and make a left turn at Lakeway Drive.

The closure is part of the broad TxDOT project to bring a diverging diamond intersection to the area.

Bradley Wheelis, a spokesperson for TxDOT’s Austin district, said the bridge construction marks the project entering its late stages. The DDI—a traffic pattern which temporarily guides vehicles to the left side of the road when crossing over a highway—is expected to open in late 2023.

Throughout the remaining construction on the bridge, two lanes of traffic will be open in each direction on Williams Drive, according to the release.

Wheelis said the transportation agency is not anticipating any similar lane closures in February or March.