This weekend is possibly the biggest construction weekend Puget Sound has seen this summer. Drivers around the Puget Sound should plan and be prepared for total road closures in Renton, Seattle, Bellevue, Lake Stevens and Clearview in Snohomish County. The weekend mantra is: leave early then add an hour.

“We’ve packed a lot of construction into one weekend,” said Lorena Eng, Washington State Department of Transportation regional administrator. “Drivers should plan alternate routes, stay on top of changing traffic conditions, and be prepared for longer than normal travel times.”

Closures

• The State Route 520 floating bridge and all connected ramps will be closed between Montlake Boulevard in Seattle and Interstate 405 in Bellevue from 11 p.m. Friday, Aug. 10, to 5 a.m. Monday, Aug. 13, while crews demolish the old Bellevue Way Northeast overpass and dig a 25-foot-deep trench to install a culvert beneath all lanes of the highway.

• State Route 167 will be closed between I-405 and South 180th Street/Southwest 43rd Street from 7:30 p.m. Friday, Aug. 10, to 4:30 a.m. Monday, Aug. 13, while crews dig a 35-foot-deep trench to install a new culvert beneath the highway.

• State Route 9 between State Route 542 and 180 Street SE in Clearview will be closed from 9 p.m. Friday, Aug. 10, to 2 a.m. Sunday, Aug. 12, to install a culvert. The detour route is eight miles long and will add 15 minutes or more to the trip.

• The intersection of State Route 92 and SR 9 will be closed from 10 p.m. Friday, Aug. 10, to 7:30 a.m. Sunday, Aug. 12, for paving.

• The city of Seattle will close the southbound I-5 off-ramp at 85th Street from 10 p.m. Friday, Aug. 10, to 5 a.m. Monday, Aug. 27, to pave 85th Street.

“Summer construction is tough to schedule, especially this type of work,” said Eng. Culvert replacement work requires low water levels and around-the-clock closures.

With SR 167 closed in Renton, SR 520 closed across the lake, and SR 9 closed in Clearview, parallel routes like I-5, the West Valley Highway, I-90 and State Route 527 (in Snohomish County) will be much busier.

“To help keep traffic moving, we will change the I-90 express lanes hours to accommodate the Seahawks game, add more incident response teams throughout the construction areas and designate the HOT lanes as HOV only on Highway 167,” said Mark Leth, WSDOT traffic engineer.