6-09-2026 8:55pm

Lake Forest Park 40th Place NE Roundabout Project Update

Chris Clasen Editor

On June 4th, 2026, the city held a Ballinger Way roundabout project update meeting. If you missed it, you can view the following summary:

The City of Lake Forest Park is spearheading a major
infrastructure upgrade at the intersection of 40th Place Northeast and State Route 104, introducing a roundabout to improve traffic efficiency and
safety. Senior Project Manager Mike Reid, along with other city officials, recently held a detailed community meeting to update residents on the project's progress, timeline, construction plans, and anticipated traffic impacts.

This post summarizes key insights from that update,
including project history, design rationale, construction phases, detour
plans, pedestrian considerations, and community concerns. The aim is to
provide a thorough overview of how this multi-phase project will unfold
over the coming months while keeping you informed about traffic
adaptations and neighborhood impacts.

Project Background and History

Initial Planning and State Funding Efforts

The idea for an intersection improvement at this location dates back to 2003, when the city proposed installing a traffic signal, but it did not meet the required warrants. In 2018, a shift in
strategy led to the adoption of a roundabout proposal, which gained initial
funding support. Since then, extensive public outreach, design efforts,
and environmental reviews have been conducted.

Additionally, Lake Forest Park secured several grants
from Washington State and WSDOT, ultimately enabling completion of the project design by early 2025. The contract was awarded in the fall of 2025
to the lowest responsible bidder.

Why a Roundabout?

Roundabouts offer multiple benefits over traditional signalized intersections:

Improved Traffic Efficiency: By balancing demands among intersection approaches and maintaining a continuous flow.
Enhanced Safety: Reducing crash frequency and severity due to slower vehicle speeds and eliminating head-on/angle collisions.
Lower Long-Term Costs: They avoid ongoing signal maintenance, power outages, and associated operational costs.
Pedestrian Improvements: Adding multiple crosswalks, upgraded lighting, and safer pedestrian crossings.

Traffic engineers have consistently found that
roundabouts significantly improve safety compared to stop-controlled or
signalized intersections, creating safer environments for all users.

Design Considerations and Project Components

Site Complexities and Utilities

The intersection poses unique challenges due to the presence of critical utilities, including water mains, power lines, gas
lines, and drainage infrastructure. Key design elements include:

Detention Vault: A large underground
vault to manage stormwater runoff, ensuring water is treated and
released at levels equal to or less than existing conditions.
Retaining Walls: Topography necessitates the construction of several retaining walls to protect homes and minimize right-of-way impacts.
Utility Upgrades: Coordination with
Lake Forest Park Water District includes upsizing and realigning water
mains to avoid conflicts with construction features.
Lighting Improvements: Installation of new streetlights to enhance night-time safety.
Tree Canopy Management: Tree removal, primarily offsite, with plans for canopy replacement within the project area to maintain green aesthetics.

Project Schedule and Construction Phasing

Timeline and Project Kickoff

Originally scheduled for earlier completion, work
experienced delays due to necessary design revisions related to utility
conflicts and pole locations. Active contractor coordination ensured that the design incorporates steel soldier piles for retaining walls that require deep foundations up to 35 feet below grade.

The current goal is to begin construction by late July
to early August 2025, with an overall project duration of approximately
18 months.

Construction Phases and Work Zones

Phase 1 – Southeast Quadrant Work:
Begins with retaining wall construction, waterline lowering, utility
relocations, and grading. This part includes the establishment of a temporary
road to maintain residential access to 184th Street.
Subsequent Quadrants – Northeast and Northwest:
Construction proceeds in a generally counterclockwise sequence,
systematically replacing infrastructure while maintaining phased access
and safety.
Final Phase – Partial Intersection Closure:
Approximately 30 to 40 days will be required for a partial closure of the intersection to complete key elements such as concrete splitter islands,
center island planting, and final paving with channelization.
Overnight Full Closure:
The last few days will involve overnight full closures for final paving
and striping activities, with carefully planned detours to minimize
daytime disruption.

Traffic Management and Detour Plans

Maintaining Traffic Flow

The city worked diligently to minimize the impacts of the closure, opting against a full closure of the corridor during peak
hours. Instead, SR 104 will maintain two lanes most of the time, down from three, which will squeeze traffic but preserve flow.

Lane Restrictions and Directional Flow

40th Place Northeast: Limited to a northbound-only lane during construction.
Southbound Detours: Southbound vehicles on 40th Place NE will be detoured to 35th Avenue NE, where they will reconnect with SR 104 farther along.
Local Access: Residents north of the intersection will retain mostly two-way access, with only a few homes subject to northbound-only access.
Reduced Lanes on SR 104: Typically
two lanes (one in each direction), compressed from the current three,
maintaining operational capacity with enhanced safety.

Traffic Data Insights

Traffic counts show:

Morning southbound volume on 40th Place NE is around
150 vehicles/hour, less than the northbound afternoon volume, which is
approximately 200 vehicles/hour.
Detouring the lighter southbound flow proved safer and less disruptive.

Coordination With Neighboring Jurisdictions

City officials coordinate closely with Kenmore,
Shoreline, and the Washington State Department of Transportation to manage
and optimize detour routes, including capturing traffic upstream to
reduce congestion within the project area.

Pedestrian and Bicycle Accommodations

Pedestrian Safety Enhancements

Alongside vehicular improvements, the project will
introduce multiple marked crosswalks equipped with pedestrian-activated
flashing beacon infrastructure—though the infrastructure may initially
be installed for future activation.

Pedestrian facilities will feature:

Improved lighting throughout the intersection for visibility at night.
Safer crossings to accommodate local school children, residents, and visitors.

Bicycle Facilities

The design includes in-lane bike accommodations,
reflecting modern best practices. Cyclists will remain on the roadway,
treated as vehicles, simplifying navigation through the roundabout.

During construction, biking through the corridor is discouraged due to safety risks.

Retaining Walls and Structural Features

Wall Types and Locations

Two types of walls support intersection geometry adjustments:

Soldier Pile Walls: Steel beams
driven deeply into the ground, reaching depths of 30 to 35 feet,
especially in the northeast and northwest corners. The exposed face may reach up to 15 feet at its highest point.
Gravity Block Walls: Engineered block walls reaching around 4 to 6 feet in height, primarily in other corners.

The final wall appearances will be determined through contractor samples and finalized during early construction.

Community Concerns and Responses

Traffic Flow and Roundabout Lane Quantity

Residents raised concerns about potential bottlenecks
and questioned why larger multi-lane roundabouts are not being
considered. Project engineers confirmed:

Current traffic volumes do not justify multi-lane roundabouts or slip lanes.
A single-lane approach prevents unsafe weaving and requires less right-of-way, thereby avoiding impacts on homes.

Truck Traffic Management

Dead-end streets pose concerns if trucks get stuck.
The city plans to install additional signage prohibiting large trucks from entering
dead-end segments, though enforcement remains a challenge.

Speed and Cut-Through Traffic

Temporary speed humps and possible local-access-only
barricades are planned to reduce speeding and cut-through traffic on side streets such as 40th Avenue NE and 35th Avenue NE.

School Zone and Pedestrian Crossing Safety

Requests for crosswalk improvements near schools and
churches are acknowledged, with potential inclusion of Rectangular Rapid
Flashing Beacons (RRFB) at crosswalks. Community members are encouraged
to submit formal requests via the city portal to ensure prioritization.

Police Enforcement and Speed Control

While no specific budget exists for enforcement in this project, the police department actively monitors problem areas and deploys speed-enforcement patrols as needed. Public Works and
Police Departments coordinate responses to changes in traffic patterns during construction.

Long-Term Plans Beyond Roundabout Installation

Complete Street Vision

The city is pursuing future funding to upgrade SR 104 from the roundabout southward to Highway 522, aiming to create a complete street with:

Dedicated bike lanes separate from vehicle lanes.
Enhanced pedestrian infrastructure.
Improved lighting, transit access, and traffic calming features.

This expansive project requires multi-year design and
funding efforts, with potential applications for partial state funding in
the near future.

Summary

The Lake Forest Park 40th Place NE roundabout project
is a comprehensive effort to address safety, traffic flow, and
pedestrian accessibility at a critical intersection. With careful
planning, phased construction, and inter-agency coordination, the city
aims to minimize disruption while delivering long-term community
benefits.

Key takeaways include:

The roundabout will enhance traffic efficiency and safety while reducing maintenance costs.
Construction involves complex utility relocations and structural work, including deep retaining walls.
Southbound traffic will be detoured to 35th Avenue NE, and lane restrictions will be carefully managed.
Pedestrian and bicycle facilities are incorporated with future-ready infrastructure.
Community input and ongoing monitoring will guide adaptive traffic management during construction.

Residents are encouraged to stay informed through
city updates and participate in feedback channels as the project
progresses toward completion.

FAQ Highlights

Q: When will construction start?
A: Expected by late July to early August 2025.

Q: How long will construction last?
A: Approximately 18 months.

Q: Will 40th Place NE be closed completely?
A: No, it will be limited primarily to northbound traffic; southbound will be detoured.

Q: How will pedestrians cross safely?
A: New crosswalks with pedestrian-activated flashing signals will be installed; lighting is also upgraded.

Q: Are bicycles accommodated?
A: Yes, in-lane bike travel is designed for the roundabout.

Q: What about truck traffic on dead-end streets?
A: Additional signage will be installed to restrict truck access.

Q: Will there be speed enforcement?
A: Police are actively monitoring and will deploy speed patrols as needed.

Stay tuned for ongoing project updates from the City
of Lake Forest Park to ensure a smooth transition through the
construction phases and a safer intersection for years to come.