Several travelers have written to Traffic Lab recently complaining of congestion where I-90 merges with northbound I-5 and pointing to the orange barrels in the collector-distributor as the culprit.

Share story

Those orange traffic barrels distracting your commute from westbound Interstate 90 to northbound Interstate 5 are part of a multimillion-dollar project to repair sections of roadway.

Several travelers have written to Traffic Lab recently complaining of congestion in the area and pointing to the orange barrels in the left lane of the collector-distributor — near Cherry Street and adjacent to northbound I-5 — as the culprit.

“Why has the left lane been closed and forced to a one car merge headed northbound from I-90 to I-5 north?” asked Tony Smith, who lives in Phinney Ridge. “The zipper merge that existed previously worked and now there is a constant back-up from I-90 to I-5 with no relief in sight.”

Traffic Lab is a Seattle Times project that digs into the region’s thorny transportation issues, spotlights promising approaches to easing gridlock, and helps readers find the best ways to get around. It is funded with the help of community sponsors Alaska Airlines, CenturyLink, Kemper Development Co., NHL Seattle, PEMCO Mutual Insurance Company and Seattle Children’s hospital. Seattle Times editors and reporters operate independently of our funders and maintain editorial control over Traffic Lab content.

Learn more about Traffic Lab » | Follow us on Twitter »

“It has made traffic worse. What is happening and what will the end state be for this merge?” Kim Bylund, who lives in Ravenna, asked.

The orange barrels have been placed there as part of Washington State Department of Transportation’s Revive I-5 project, a series of weekend work sessions to repair and resurface portions of Interstate 5.

In the normal configuration, the collector-distributor narrows to one lane where drivers merge onto I-5.

WSDOT created a temporary second lane as part of the I-5 repair project.

But Tom Pearce, spokesman for the Washington State Department of Transportation (WSDOT), said that left lane on the collector-distributor enters I-5 at an angle “that doesn’t allow for a safe merge” with regular freeway traffic.

The second lane is used when crews temporarily close all northbound I-5 lanes on a few weekends and divert the traffic onto the collector-distributor. Both lanes can be used safely to enter I-5 then because there is no traffic coming from the south.

Crews have painted a stripe down the middle of the collector-distributor to define those lanes. However, because the work — including painting the stripe — is weather dependent, the stripe is left there so crews don’t have to repaint it when needed.

“We’ve had cases on other projects where we needed to postpone an entire weekend of work because it rained the night we were going to stripe,” Pearce said.

So the state uses the barrels to restrict that left lane when it’s not needed.

That’s why you see the orange barrels restricting the left lane even when there is no active construction.

“We know it’s an inconvenience and we appreciate the public’s patience,” Pearce said.

WSDOT has closed lanes for construction during the weekends of April 20-23, May 11-14 and May 18-22. It closed a section of all northbound lanes on June 1-4.

The next work session, a full closure of northbound I-5 at the West Seattle Bridge offramp, is scheduled for this weekend, from 8 p.m. Friday until 5 a.m. Monday.

As for when the repairs will be finished, “We’re still working on that,” Pearce said.

“The current striping configuration will remain in place at least through the summer,” he said.

Got a question?

Do you have a question about transportation for Traffic Lab? We’d like to try to answer it. Send your questions to or tweet us at @STtrafficlab, and we may feature them in an upcoming column.