The busy Interstate 5 and U.S. 101 interchange in Olympia will be the focus of vital bridge structural repair work over the weekends of Sept. 12 and Sept. 19. Preparations for the two weekends will require lane and ramp closures each Thursday night, Sept. 11 and Sept. 18.

During the two weekends, contractor crews working for the Washington State Department of Transportation will replace a 171-foot-long bridge expansion joint that spans the width of the roadway. The 28-year-old expansion joint has deteriorated to the point that temporary repairs no longer are effective, and it must be replaced to keep drivers safe and traffic moving.

Both weekends include day and night lane and ramp closures for both directions of I-5 near Capitol Lake. Over a typical weekend, more than 276,000 vehicles use this stretch of I-5. Roughly 190,000 vehicles travel on U.S. 101 approaching I-5. WSDOT traffic engineers warn that drivers likely will face lengthy backups and delays because no convenient alternate state routes are available. Even with traffic volumes decreasing by 30 percent over the two weekends, traffic models show backups reaching 14 miles, with especially heavy congestion expected on southbound I-5.

“The I-5/U.S. 101 interchange is one busy interchange, and it’s a tough place to work,” said WSDOT Project Engineer Ricky Bhalla. “We need drivers to change their normal driving habits to help prevent miles of backups over the next two weekends while our contractor completes this important work.”

Sept. 11 night closures

Starting Thursday, Sept. 11, motorists will encounter night closures on I-5 and U.S. 101 as crews re-stripe I-5 lanes toward the highway median. At 8 p.m., crews will close the left northbound I-5 lane approaching Deschutes Way Southwest. At 10 p.m. they will close a second northbound I-5 lane and two ramps: 1) the southbound U.S. 101 exit to northbound I-5; and 2) Deschutes Way Southwest to northbound I-5. U.S. 101 motorists will be detoured onto southbound I-5 and through the Tumwater Boulevard interchange to reach northbound I-5.

The I-5 lanes and the U.S. 101 ramp will reopen at 5 a.m. Friday, Sept. 12. The Deschutes Way Southwest on-ramp to northbound I-5 will remain closed through Monday morning, Sept. 15.

Sept. 12-15 closure details

• Drivers can expect major lane and ramp closures along both directions of I-5 near Capitol Lake between 7 p.m. Friday, Sept. 12, and 5 a.m. Monday, Sept. 15.

I-5 lane reductions

• I-5 will be reduced to one lane in each direction between 10 p.m. and 8 a.m. Friday, Sept. 12 through Sunday, Sept. 14.
• During the daytime hours on Saturday and Sunday, I-5 will be open to only two lanes in each direction.

Ramp closures and reductions

• The Deschutes Way Southwest on-ramp to northbound I-5 will close from 10 p.m. Thursday, Sept. 11, to 5 a.m., Monday, Sept.15.
• The Henderson Avenue/14th Avenue Southeast on-ramp to southbound I-5 will be closed from 10 p.m. Friday, Sept.12, to 5 a.m., Monday, Sept.15.
• U.S. 101 on-ramp to northbound I-5 will be reduced to one lane from 10 p.m. Friday, Sept.12, to 5 a.m., Monday, Sept.15.

Stay engaged and have a backup plan

• Drivers who cannot avoid I-5 in Olympia during the two weekends are advised to:
• Consider traveling through the area early (before 10 a.m.) or late (after 8 p.m.) in the day.
• Stay informed by checking WSDOT traffic alerts webpage, following WSDOT’s regional Twitter account, and by calling 5-1-1.
• Expect considerable delays with miles of stop-and-go traffic.
• Be prepared – have a full tank of gas, have diversionary games for children traveling in the car and pack patience.
• Allow plenty of extra time to reach travel destinations.
• People traveling between Seattle and Portland might want to consider advance reservations on Amtrak Cascades. Amtrak Cascades offers four round trips per day between Seattle and Portland.

Why is this work occurring?

The concrete surrounding the 28-year-old steel expansion joint has deteriorated where I-5 and U.S. 101 merge. To make lasting repairs, crews will chip out and replace the concrete abutting the joint. The bridge expansion joint crosses all lanes of northbound and southbound I-5 as well as U.S. 101 on-and-off-ramps. It allows the bridge to move and flex with changing traffic and weather conditions. Joints that fail can unexpectedly pop up into traffic, resulting in emergency closures of lanes to replace or repair them. Since no one can plan for a failure and subsequent emergency closure, WSDOT wants to repair these joints under scheduled closures before they fail.