Renton to Bellevue construction on I-405 continues to ramp up this fall

By Victoria Miller

This has been a year of change for most of us, and that includes Interstate 405. The I-405, Renton to Bellevue Widening and Express Toll Lanes Project construction is underway!

The Renton to Bellevue project is part of our Master Plan, which is a set of long-term improvements to help give people choices and get more people moving through the corridor. We have partnered with Sound Transit and King County Parks to make Renton to Bellevue a multimodal project. The project will include a direct access ramp and inline transit station at the Northeast 44th Street interchange that will help support Sound Transit's Bus Rapid Transit line, as well as two sections of the new King County Eastrail along Lake Washington and in Bellevue north of I-90. This project also addresses several fish culverts as part of our commitment to correct fish barriers by 2030.

Drivers on the south end of I-405 have probably noticed lane and ramp closures beginning in Renton and south Bellevue as part of the project. The project will build a dual express toll lane system between State Route 167 in Renton and Northeast Sixth Street in Bellevue, giving travelers a choice for a more reliable trip. This project will also add two southbound auxiliary lanes, one between I-90 and 112th Avenue Southeast/Lake Washington Boulevard Southeast (Exit 9), and another between Northeast 44th Street and Northeast 30th Street.

We awarded this design-build project during summer 2019 and construction has been ramping up as the design is being completed. So far, our project team has been hard at work with the final design for the project, and construction crews have made good progress on the Eastrail. Now the construction has arrived near the I-405/Northeast 44th Street interchange in Renton, which is where the bulk of the work will be taking place for most of the life of the project. Once the project is complete in 2024, this interchange will look very different to both drivers and pedestrians in the area.

Traffic shifts make way for corridor work

Crews recently completed the project's first traffic shift on northbound I-405 between North 30th Street and Northeast 44th Street, also known as the Kennydale Hill in Renton. The traffic shift was necessary to provide crews enough space to create a new construction work zone. The same number of lanes remain in place as part of the shift, which moved the northbound lanes of traffic farther to the left side of the roadway.

A look at the first traffic shift on northbound I-405.

The traffic shifts for this project will be necessary for crews to safely complete the work behind barriers throughout the project area. Drivers should prepare to see a lot more construction over the next few years, until 2024 when the project is anticipated to open to traffic.

This first mainline traffic shift occurred between North 30th Street and Northeast 44th Street.

As construction continues to become more visible to travelers in the area, please make sure to keep up with the project's progress and weekly closures on the project webpage and the I-405 construction updates webpage.

Given the current circumstances regarding COVID-19, our crews continue to work closely with guidance from Gov. Inslee's "Safe Start" reopening plan to ensure all fieldwork complies with current construction requirements. The weekly closures are performed under COVID-19 safety plans and are monitored by both contractor safety staff and our inspectors to protect the health of crews and the public.

Opening the new Thorne Lane interchange – Part 1

Update: September 29, 2020
The contractor has updated their schedule for the opening of the new Thorne Lane "high" bridge. The new schedule shows the bridge will open the week of Oct. 14. WSDOT will provide more information once it is available.

By Cara Mitchell

It's going to take several weeks. You'll need to take some detours. But there's light at the end of the tunnel. The I-5/Thorne Lane interchange in Lakewood is oh so close to opening!

We'll do what we can to minimize closures and detours as much as we can and we ask for just a bit more patience as we reach this big milestone.

Setting the scene and what to expect

Travelers who use I-5 near Thorne Lane and Murray Road currently drive under three bridges – two new ones and an old one. You can take a look at this overhead photo below to familiarize yourself with each new part of this interchange.

An overhead look of what to expect at the new Thorne Lane interchange.

Over the next four weeks, a series of changes will occur as crews open up different sections of the intersection. Note that dates can change due to weather.

• Week of Sept. 28 
  • Open new Thorne Lane "high" bridge that connects Tillicum and Woodbrook neighborhoods
• Oct. 9-12 
  • Weekend full closure of Thorne Lane overpass and I-5 ramps
• Oct. 12
  • Thorne Lane "low" bridge connecting southbound I-5 to Murray Road opens
• Oct. 16 & 17
  • Demolish and remove old Thorne Lane overpass

To start, we're going to focus on the first phase of work – opening the Thorne Lane "high" bridge.

Opening Thorne Lane "high" bridge

As early as Tuesday, Sept. 29, crews will open the new 344-foot-long bridge that spans both I-5 and the railroad tracks. To keep things simple, we are calling this new bridge the Thorne Lane "high" bridge. It will connect local streets using new roundabouts at Murray Road and Union Avenue.

Here's what travelers can expect when the Thorne Lane high bridge opens late this month.

When the new "high" bridge opens, southbound I-5 travelers exiting to Thorne Lane will continue to use the old overpass to turn right to Thorne Lane, or left to Murray Road. Travelers headed to Tillicum can either continue to follow the existing detour on Thorne Lane to Union Avenue, or use the roundabout at Murray Road and cross the new "high" bridge to Union Avenue. This temporary traffic pattern will remain in place until the weekend of Oct. 9, when crews begin work to open the Thorne Lane "low" bridge. That will be covered in a future blog.

Why roundabouts?

There is a good reason why we used roundabouts on the Thorne Lane high bridge – they move traffic through an intersection faster than a traffic signal. Traffic signals on the existing interchange were a necessary component to coordinate the movements of travelers going to and from I-5, railroad activity, and pedestrian/bicyclist traffic. The complexity of the network of streets with the railroad required signal timing that created substantial delays and backups. 

The new interchange design helps relieve congestion by separating where and how traffic flows. The new high bridge is designed to keep bikes, pedestrians and vehicles moving without the need for traffic signals between Lakewood's Tillicum and Woodbrook neighborhoods. This helps reduce congestion.

Is this part of the SR 704 Cross Base Highway project?

We receive this question a lot. The answer is, No. The SR 704 Cross Base Highway project is on indefinite hold. There is no current funding for the project and because so much time has passed since the first phase was constructed, in 2008, a lengthy environmental review process would need to play out again. 

Moving into fall

Here is a list of work coming up in October both at Thorne Lane and on southbound I-5: 

• The new Thorne Lane "low" bridge will open, bringing with it several detours.
• The old Thorne Lane overpass will be demolished, and that will require overnight closures of I-5. 
• Last but not least, a second traffic switch for southbound I-5 lanes will occur near Berkeley Street as part of raising the elevation of the highway 14 feet. 

Putting hard dates to all this while scheduling around weather is at times like herding cats. We will do our best to provide updates as work progresses on what to expect for travelers in the coming weeks. 

As always, we ask you help keep our crews safe by driving the posted speed limit and be mindful of work zones.

One more SR 202 closure for culvert replacement coming up

By Tom Pearce

One down, one to go.

Just west of Fall City, a second closure of State Route 202 between Southeast 31st Street and West River Road is scheduled for the weekend of Sept. 12-13. In late August we closed the highway closer to Sammamish to replace a culvert that carries Patterson Creek under the highway.

This next closure allows us to replace a couple of culverts keeping salmon and other fish from continuing upstream. From 9 p.m. Friday, Sept. 11 to 5 a.m. Monday, Sept. 14, the road will be closed and all traffic will follow a signed detour. The route is fairly narrow, so truck traffic will need to use I-90, I-405 and SR 520 to get around the closure.

The culverts being replaced under SR 202 carry unnamed tributaries to Patterson Creek. They are narrow and water often moves too fast through them for fish to continue upstream.

Why a full closure?

The stretch of SR 202 near these culverts is relatively narrow at this location, which makes it impossible to keep a lane open during culvert replacement. 

During the full highway closure, our contractor crews will dig up both culverts and replace them with larger box culverts. These will be able to carry natural creek beds, which will make it easy for fish and other marine life to move up and downstream. It's all part of our effort to improve fish passage under state highways, which will help increase fish populations in Puget Sound.

Patterson Creek culvert complete

During the last weekend of August, it took us about 55 hours to replace the culvert for Patterson Creek just east of Sammamish. Similar to what we will be doing during the Sept. 12-13 closure, we had to dig up the old culvert from about 10 feet beneath the roadway. Then we put in a new, larger structure and paved a new roadway back on top.

Replacing these culverts will open up about 11½ miles of additional habitat for salmon and resident fish. That's more area to spawn and for young fish to grow.

Crews lift a section of concrete culvert into place at Patterson Creek.

Improving salmon habitat

Opening up culverts and improving waterways means more species will be able to make the journey to spawning grounds and expanded rearing habitat for young fish. 

By the year 2030, we plan to replace hundreds more fish barriers under our highways. In some cases the narrow passages need to be widened. In other locations, creek levels have dropped, creating too large of a jump for migratory fish to make. 

We appreciate your patience not just with the culvert removals happening this month under SR 202, but with all our future fish passage projects in the years to come.

COVID-19 presents unique challenges for summer intern

By Taylor Lenderman

This summer I was fortunate enough to land an internship at the Bellingham project engineering office as a transportation engineering intern. I am starting my senior year at Gonzaga University and working towards my bachelor's degree in civil engineering. I was thankful to be in my hometown, Bellingham, and spend summer in the beautiful Pacific Northwest.

Taylor Lenderman, an engineering intern in our Bellingham office,
learns to form a concrete cylinder.

My experience as an intern was likely unique compared to the typical intern experience. COVID-19 disrupted the work environment quite significantly. As employees were required to telework from home, being a new face presented some challenges. I was worried that it would be difficult to get help and support from staff, and that learning opportunities would be limited. Luckily, everybody I had the chance to work with was more than willing to help me, and I could not be more thankful! I was able to develop relationships with employees whether I was in the field or teleworking from home. Even though I may not have met everyone in person, I still had the ability to meet virtually and made a connection with just about every employee in our office.

Intern Taylor Lenderman surveys a creek bed near SR 548 in Whatcom County.

So what did I do?

The internship offered several opportunities to get my feet wet. I assisted an inspector on two construction projects, learned how to test materials, observed the work of survey crews, and visited some cool projects outside of the Mt. Baker region.

One of the first projects I helped inspect was at the Bow Hill weigh station. I saw how asphalt is milled and replaced with fresh new asphalt, how concrete panels are poured, and learn the basics of inspection. This project was a learning opportunity for myself and several young engineers in our office. Struggling and learning together as a team throughout this project prepared ourselves for a much bigger fish passage project that was scheduled at the end of July.

Taylor Lenderman stretches his arms wide to show the size of a new 12-foot culvert.

One of the most memorable experiences I had was shadowing an inspector on a salmon fish passage project at Hoag's Creek on SR 11. This project involved replacing an old concrete culvert with a much bigger culvert, allowing salmon to spawn upstream. During the road closure that lasted roughly two weeks, I saw some major progress as contractor Tiger Construction worked around the clock to excavate the old culvert and replace it with the new one. It was amazing how much was accomplished during those two weeks! It was fascinating to watch how the jobsite completely changed from the beginning of the project to end. I was impressed with how much progress was made with the large equipment, countless loads of material delivered from dump trucks, and the construction crew which brought a tremendous amount of effort to the job each day. I must tip my inspector's hard hat to the contractor for all the hard work they accomplished!

Taylor Lenderman is flanked by engineers Vivianne Tabuena (left)
and Laura Brown at the Bow Hill weigh station.

Looking back, I gained some valuable experience in the field and developed connections throughout the agency. As an intern and having no prior training, it was difficult to do tasks on my own because I often had to rely on other employees for their guidance. I tried to provide an outside perspective, ask good questions, and soak in every learning opportunity like a sponge. Luckily, I was a part of a welcoming and supportive team that was always more than willing to help me when needed. I would like to thank the entire Bellingham office for letting me tag along as an inspector to jobsites, answering every question I had, and most importantly, welcoming me and making me feel like a part of their team. I have learned so much over these past few months that I can apply and expand on as I progress in my final year of school and engineering career. Thank you for an awesome summer!