Drivers on Highway 9 Thursday pass South Lake Stevens Road in Lake Stevens. The Washington State Department of Transportation is installing a roundabout at the intersection to improve traffic safety ahead of planned construction for a Costco. (Olivia Vanni / The Herald)

Drivers on Highway 9 Thursday pass South Lake Stevens Road in Lake Stevens. The Washington State Department of Transportation is installing a roundabout at the intersection to improve traffic safety ahead of planned construction for a Costco. (Olivia Vanni / The Herald)

As Lake Stevens braces for Costco traffic, Highway 9 gets new roundabout

Expect traffic disruptions and weekend closures as crews build the roundabout at Highway 9 and South Lake Stevens Road.

With construction underway at a new Costco, roads are already changing in Lake Stevens.

As crews get to work, drivers could see some traffic disruptions.

Interwest Construction, Inc., was set Monday to prepare the intersection of Highway 9 and South Lake Stevens Road for a two-lane roundabout. The Washington State Department of Transportation (WSDOT) hired the contractor for the project estimated to cost $8.8 million. The roundabout accounts for about $5.1 million.

Construction is expected to conclude this fall.

“This whole project is really to facilitate changes for the Costco going in,” WSDOT spokesperson Tony Black said.

An average of 18,000 vehicles used the nearby stretch of Highway 9 daily in 2020, WSDOT data shows.

About 800 cars are expected in the area during the peak evening commute near the Costco, according to project documents.

The Washington State Department is installing a roundabout at the intersection of Highway 9 and South Lake Stevens Road. (WSDOT)

The Washington State Department is installing a roundabout at the intersection of Highway 9 and South Lake Stevens Road. (WSDOT)

The Costco building is planned to be 160,000 square feet, with over 800 parking spaces and a gas station with 30 pumps. It would occupy the area from 91st Avenue SE east to Highway 9, and from 20th Street SE south to 24th Street SE and South Lake Stevens Road.

In all, the retail space would cover almost 37 acres.

The nearest Costco is in Everett, about 10 miles away via the U.S. 2 trestle and I-5.

As part of its development agreement, the company is building new segments of 91st Avenue SE and 24th Street SE. Both would connect to the store’s parking lot, and the latter links to Highway 9 and the roundabout.

At least two weekend closures are needed for roundabout work. The first is 9 p.m. Friday to 4 a.m. Monday. A detour will take pass-through drivers to U.S. 2, but local access will remain.

Crews will shift traffic to the east side of Highway 9. That lets them start work on the west side and South Lake Stevens Road, which will be closed about eight months. A detour for that access is set for 32nd Street SE and 91st Avenue SE.

The detour for drivers heading through the area goes to Highway 204 or U.S. 2. It could cause backups at the stop sign intersection at 20th Street SE.

Some evening weekday Highway 9 lane closures are expected but have not been scheduled yet.

A map of the road closure and detour during weekend closures for construction of a roundabout at Highway 9 and South Lake Stevens Road in Lake Stevens. (WSDOT)

A map of the road closure and detour during weekend closures for construction of a roundabout at Highway 9 and South Lake Stevens Road in Lake Stevens. (WSDOT)

A state study determined the roundabout was safer than a traffic signal at the South Lake Stevens Road intersection, Black said.

“At a signal, you have the chance of someone trying to run the light,” Black said.

Instead, drivers are expected to slow from the highway’s speed limit of 55 mph to between 25 and 35 mph through the roundabout.

Pedestrians will be able to cross the highway there, too. A crosswalk, with space for pedestrians to wait if necessary, is going in on the north end of the roundabout.

Without crossing signals, roundabouts can be more harrowing for pedestrians, especially those with disabilities.

Larry Watkinson, who works on Americans with Disabilities Act compliance for the Washington State Department of Transportation, said they can be safer with raised crossings, rapid flashing beacons and a vehicle approach that forces slower speeds.

The highway project also includes replacing a culvert under the road for Centennial Creek. The existing corrugated steel pipe culvert is 2½ feet in diameter and 63 feet long, according to a permit application.

It isn’t considered a barrier by the Washington Department of Fish and Wildlife, but it has to be replaced because of impacts from the road project.

A map of the work area during construction of a roundabout at Highway 9 and South Lake Stevens Road in Lake Stevens. (WSDOT)

A map of the work area during construction of a roundabout at Highway 9 and South Lake Stevens Road in Lake Stevens. (WSDOT)

The new passage will be 19 feet wide and 6 feet above the water.

That work won’t start until after July 5, in compliance with state fish management rules.

The state also is building a stormwater pond with two cells just west the current intersection. Its overall footprint is about 120 feet by 120 feet.

Have a question? Call 425-339-3037 or email streetsmarts@heraldnet.com. Please include your first and last name and city of residence.

Talk to us

> Give us your news tips.

> Send us a letter to the editor.

> More Herald contact information.

More in Local News

Customers enter and exit the Costco on Dec. 2, 2022, in Lake Stevens. (Olivia Vanni / The Herald)
Costco stores could be impacted by looming truck driver strike threat

Truck drivers who deliver groceries and produce to Costco warehouses… Continue reading

Two Washington State ferries pass along the route between Mukilteo and Clinton as scuba divers swim near the shore Sunday, Oct. 22, 2023, in Mukilteo, Washington. (Ryan Berry / The Herald)
Ferry system increases ridership by a half million in 2024

Edmonds-Kingston route remains second-busiest route in the system.

Fernando Espinoza salts the sidewalk along Fifth Avenue South on Thursday, Feb. 6, 2025 in Edmonds, Washington. (Olivia Vanni / The Herald)
Think this is cold, Snohomish County? Wait until Tuesday

Tuesday could bring dangerous wind chill during the day and an overnight low of 19 degrees

The Washington State Department of Licensing office is seen in 2018 in Seattle. (Sue Misao / The Herald)
Drivers licensing offices to close Feb. 14-17

Online services are also not available Feb. 10-17. The Washington State Department of Licensing said the move is necessary to upgrade software.

Pharmacist Nisha Mathew prepares a Pfizer COVID booster shot for a patient at Bartell Drugs on Broadway on Saturday, Oct. 1, 2022, in Everett, Washington. (Ryan Berry / The Herald)
Everett lawmakers back universal health care bill, introduced in Olympia

Proponents say providing health care for all is a “fundamental human right.” Opponents worry about the cost of implementing it.

Robin Cain with 50 of her marathon medals hanging on a display board she made with her father on Thursday, Jan. 2, 2025 in Lake Stevens, Washington. (Olivia Vanni / The Herald)
Running a marathon is hard. She ran one in every state.

Robin Cain, of Lake Stevens, is one of only a few thousand people to ever achieve the feat.

People line up to grab food at the Everett Recovery Cafe on Wednesday, Dec. 4, 2024 in Everett, Washington. (Olivia Vanni / The Herald)
Coffee, meals and compassion are free at the Everett Recovery Cafe

The free, membership-based day center offers free coffee and meals and more importantly, camaraderie and recovery support.

Devani Padron, left, Daisy Ramos perform during dance class at Mari's Place Monday afternoon in Everett on July 13, 2016. (Kevin Clark / The Herald)
Mari’s Place helps children build confidence and design a better future

The Everett-based nonprofit offers free and low-cost classes in art, music, theater and dance for children ages 5 to 14.

The Everett Wastewater Treatment Plant along the Snohomish River on Thursday, June 16, 2022 in Everett, Washington. (Olivia Vanni / The Herald)
Everett water, sewer rates could jump 43% by 2028

The rate hikes would pay for improvements to the city’s sewer infrastructure.

The bond funded new track and field at Northshore Middle School on Thursday, Oct. 24, 2024 in Bothell, Washington. (Courtesy of Northshore School District)
Northshore School District bond improvements underway

The $425 million bond is funding new track and field complexes, playgrounds and phase one of two school replacements.

Outside of the updated section of Lake Stevens High School on Thursday, Feb. 27, 2020 in Lake Stevens, Wa. (Olivia Vanni / The Herald)
Lake Stevens, Arlington school measures on Feb. 11 ballot

A bond in Lake Stevens and a levy in Arlington would be used to build new schools.

Lake Stevens Sewer District wastewater treatment plant. (Lake Stevens Sewer District)
Lake Stevens sewer district trial delayed until April

The dispute began in 2021 and centers around when the city can take over the district.

Support local journalism

If you value local news, make a gift now to support the trusted journalism you get in The Daily Herald. Donations processed in this system are not tax deductible.