Paving to slow southbound I-405 through Renton this weekend

The closure

State crews will close the carpool lane on southbound I-405 between State Route 167 (the Valley Freeway) and State Route 181 (the West Valley Highway) around the clock from 9 p.m. Friday, Aug. 28, to 5 a.m. Monday, Aug. 31.

Travelers southbound on Interstate 405 should expect long delays this weekend as the state closes the carpool lane to pave the new bridge over Oakesdale Avenue Southwest.

Or, better yet, take a different route to your destination, including this weekend’s Mariners game and Seahawks game.

Traffic will be funneled into two lanes as crews close the southbound I-405 carpool lane between State Route 167 (the Valley Freeway) and the West Valley Highway to pave the I-405 bridge over Oakesdale.

“Paving the bridge this weekend means we will stay on track to open an additional I-405 lane in each direction this fall,” said Paula Hammond, Washington Transportation secretary. “The added capacity on I-405 between the I-5 and SR 167 interchanges means faster speeds and smoother movements through the area around two of our state’s most congested interchanges.”

Crews are taking advantage of the good weather to complete the final stages on the new bridge over Oakesdale Avenue. Crews will pour concrete, which takes 42 hours to cure, in addition to paving, striping and cleanup work.

Electronic message boards on I-405, I-5 and SR 167 will notify drivers of the upcoming closure. Drivers looking for alternate routes around the closure to Seattle can use SR 900 (Sunset Boulevard) or northbound I-405 to westbound I-90 to get to I-5. Through Renton, drivers can also take Grady Way to get back onto southbound I-405 at the SR 181 interchange.

“We need more than 30 percent of the traffic to use alternate routes this weekend or drivers could experience hour-long delays or longer on southbound I-405 and northbound SR 167,” said Jonathon Harris, the transportation department project engineer. “This isn’t just about the carpool lane on I-405. We expect traffic delays on SR 167 as well.”

The work is part of the I-405/I-5 to SR 169 Stage 1 – Widening Project. WSDOT and contractor crews are building a new lane in each direction on I-405 between I-5 and SR 167 and a new lane on southbound SR 167 between I-405 and Southwest 41st Street.

Alternate route maps and project information is available here.