From the I-90 floating bridge and a new overpass in Kent to the Highway 520 rebuild from Montlake to I-5, readers are wondering what work is underway.

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It’s summertime and that means construction crews are out in full force, working on transportation projects while the weather is warm and dry.

Several readers have asked Traffic Lab about the status of the work they see along their travels.

Here’s an update, based on questions we’ve received. The questions have been edited for clarity.

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, Sabey Corp., Seattle Children’s hospital and Ste. Michelle Wine Estates. Seattle Times editors and reporters operate independently of our funders and maintain editorial control over Traffic Lab content.

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Q. Why have barges been along the western span of the Interstate 90 floating bridge over the past few weeks? — Gale Otter, Mercer Island

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A. The Washington State Department of Transportation is replacing about 30 steel anchor cables on the I-90 floating bridge between Seattle and Mercer Island, Harmony Weinberg, WSDOT spokeswoman, said in an email.

About 110 steel cables help stabilize each of the two spans. However, she said, they need to be replaced every 25 to 30 years “due to wear and tear from wind, waves, currents, and of course, traffic.”

The cable replacement happens in batches. Work began in April and is expected to be completed this fall, she said.

Q. There seems to be an overpass or something being erected over [Highway] 167 between Kent and Renton. I’ve asked around and no one seems to know where it is coming from and where it is going. I assume it will be quite useful, but I am very curious. — Summer Wolf, Covington

A. The South 224th Street project is one of many that the city of Kent has been developing to provide an east-west corridor between Interstate 5 and Kent’s East Hill, said Carla Maloney, a design engineering manager in Kent’s public works department.

As part of the project, a new, three-lane roadway and bridge over Highway 167 is being constructed to connect to the Kent Valley and provide better access to Interstate 5, the Highway 509 Gateway and Highway 167.

Maloney expects the new connection to reduce travel time for residents and businesses east of Highway 167.

Construction began in October 2017 and is expected to be complete in fall 2019.

Q. For the past few months, the right northbound lane on Fourth Avenue [in South Seattle] has been closed over the railroad tracks. There doesn’t seem to be any work being done. Any insight? This is just south of Costco. — Chris Cassidy, Seattle

A. In October, the Seattle Department of Transportation announced on its blog that the agency had to close the right northbound lane of Fourth Avenue South over the railroad tracks for up to a year. An inspection had found some cracking there in the Argo Bridge that needed repairs.

“While it’s safe to travel on, we wanted to reduce the load on the outer edges of the bridge deck, which is why we needed to close that lane,” according to the blog post.

Two lanes of southbound traffic and one northbound lane remain open, but trucks must use the center lane when crossing the bridge.

After repairs are completed, the northbound curb lane will reopen, but oversize trucks will not be allowed to use the bridge.

Construction should finish by the fall.

Q. I’m curious about the next steps in finishing the new 520 bridge from Montlake to Interstate 5. — Scott Harlan, Redmond

A. Construction is scheduled to begin later this year on the first of three phases in the Rest of the West project to rebuild the Highway 520 corridor from Interstate 5 to Lake Washington.

The Montlake phase is up first. Crews will build a new Montlake interchange, a landscaped lid over Highway 520, a bicycle/pedestrian land bridge east of the lid, and a new approach bridge for eastbound traffic heading over the lake.

The $400 million Montlake phase is expected to be completed in four to five years.

The second construction phase will include a new Portage Bay Bridge for 520, and the third phase a second Montlake Boulevard drawbridge over the Montlake Cut.

The Portage Bay phase is scheduled to start between 2020 and 2022 and take six years to complete, and the Montlake Cut phase should begin in 2024 and last three years.

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 trafficlab@seattletimes.com or tweet us at @STtrafficlab, and we may feature them in an upcoming column.