Drivers who use southbound Interstate 5 in South King County should plan for extended overnight work hours from Friday evening, Sept. 16, through Sunday morning, Sept. 18.

The additional lane reductions and hours will allow Washington State Department of Transportation contractor crews to expedite paving and grinding work on three segments of southbound I-5 between Interstate 405 in Tukwila and South 320th Street in Federal Way.

This weather-dependent work will reduce the number of future overnight lane closures for a rehabilitation project that began in March.

I-405 to State Route 516

• Lane reductions will start at 8 p.m. Friday and Saturday.

• By 10 p.m. nightly, traffic will be reduced to one right lane.

• Lanes will begin reopening at 10 a.m. Saturday and Sunday.

South 260th Street to Military Road

• Lane reductions will start at 8 p.m. Friday.

• By 9 p.m., traffic will be reduced to three left lanes.

• Lanes will begin reopening at 9 a.m. Saturday.

Military Road to South 320th Street

• Lane reductions will start at 8 p.m. Friday and Saturday.

• By 11:59 p.m. nightly, traffic will be reduced to one left lane.

• Lanes will begin reopening at 4:30 a.m. Saturday and Sunday.

Ramp closures

• The South 188th Street on-ramp to southbound I-5 closed 9 p.m. to 5 a.m. nightly.

• The South 200th on-ramp for southbound I-5 closed 9 p.m. to 5 a.m. nightly.

• The South 272nd Street off- and on-ramps closed 9 p.m. Friday to 9 a.m. Saturday.