A key interchange in northwest Houston will close for six weeks, as work proceeds on the U.S. 290 widening project.

Westbound access from U.S. 290 to the Sam Houston Tollway will close Friday at 9 p.m. It is scheduled to open by 5 a.m. on March 7, according to the Texas Department of Transportation. The Harris County Toll Road Authority, which manages the tollway, is telling drivers to expect delays, as the closing involves both northbound and southbound tollway access from westbound U.S. 290.

Those headed north on the Sam Houston Tollway will use a temporary exit west of Gessner and use the frontage roads to merge onto the tollway north of Philippine.

PHOTOS: 25 most congested freeways in Texas and how much they cost drivers

Drivers headed south on the tollway will continue west on U.S. 290, exit at Jones, and return to the tollway via eastbound U.S. 290.

The closing is needed to complete paving and other work at the interchange, including rebuilding a support column for the connector ramps from U.S. 290 to the tollway. The $1.8 billion project will widen U.S. 290 to at least five lanes in each direction from Loop 610 to Texas 6, and four lanes in each direction to Waller.

The 38-mile project, which includes interchanges and new entrance and exit ramps at local streets, is on pace to finish in late 2017, TxDOT officials said.