Northeast 179th Street and Northeast 29th Avenue Intersection Improvements

Public Works is reconstructing the intersection of Northeast 179th Street and Northeast 29th Avenue. The existing single-lane, all-way stop-sign-controlled intersection will be replaced with a roundabout. This change is necessary to accommodate increasing traffic volumes associated with residential and commercial development in the area.

Project Timeline

Design: spring 2020 – spring 2025
Construction: summer 2025

Budget

The total budget identified for the project is $23.2 million, including a federal grant for approximately a third of the cost.

Contact

Michael Tracy, project engineer
Clark County Public Works
564.397.4946
michael.tracy@clark.wa.gov

Construction Updates

Beginning Friday, March 6, Northeast 50th Avenue will close between Northeast 159th and 179th streets.

The request to close Northeast 50th Avenue was submitted by a contractor working on a private development project in the area. To install new sanitary utility infrastructure for the development project, the construction must excavate in both travel lanes on the roadway. The required work area will not safely accommodate the proposed work and traffic simultaneously.

The closure, not to exceed 80 days, was approved by the county council.

The contractor is required to maintain access to adjacent properties and emergency vehicles.

For these non-county project closures, the contractor is responsible for notifying local residents. More information is in the staff report to council about the closure.

A map showing the locations of road closures on Northeast 179th Street and Northeast 50th Avenue, and detour routes.

The next stage of closures begins Jan. 5 when the east leg and north leg will close to through traffic:

East leg: Northeast 179th Street from Northeast 29th Avenue to approximately Northeast 33rd Avenue
North leg: Northeast 29th Avenue from Northeast 179th Street, north for several hundred feet (map below)

Access to properties within the closed areas will be maintained.
A signed detour will guide drivers around the closed sections.
During work hours, travelers on the open segments may encounter alternating one-way traffic control and delays.

General Construction and Closure Information

Construction began in August 2025 and is scheduled to continue through spring 2027.

Reconstruction of the intersection requires building two bridges over fish-bearing streams and the construction of a large stormwater treatment facility. With environmental and engineering constraints, it is not possible to construct the project without road closures. Closure schedules are subject to change. More specific closure and reopening dates will be posted on the project webpage as soon as they are known.

It is not possible to know the exact dates of future construction stages and closures at this time. We will share new information via mail, email, our website, social media, news media and signage as soon as it is available.

Construction activities generally 7 a.m. to 3:30 p.m., Mondays through Fridays, occasionally Saturdays
Dust and noise abatement measures by the construction contractor
Intermittent single-lane closures on open roads in the project area

We understand that road closures greatly impact your day-to-day routines. We are working with partners to minimize disruptions however possible. During construction and closures, we commit to:

Confirming that all service providers, including waste collection, mail and emergency response services, have received all needed information about the closures and detours and have initiated their internal processes for ensuring continued services for local properties
Promptly investigating and following up on questions and feedback related to detours and traffic, closures, construction activities and service disruptions
Communicating new information as soon as it is available, and providing project updates throughout construction
Ensuring access to all properties - no properties will be inaccessible because of closures or construction; delays for access will be limited to approximately 10 minutes

Closures will be marked with signage and barriers, which may include "Local Access Only" signs. “Local access” refers to non-through traffic, i.e., traffic that is accessing a property located within the closed area.

Project Information

Click here to view the map of the project area.

This project contributes to improvement of the local transportation system in support of the Clark County Comprehensive Growth Management Plan. Development is increasing traffic volumes along the Northeast 179th Street corridor. This project is one of several that, when complete, will improve travel times, upgrade stormwater management, improve safety and bring the corridor up to current road standards.

The roundabout will be designed to operate initially with a single lane. It will be sized to be expandable to multi-lanes in the future to align with the eventual widening of Northeast 179th Street to four lanes. Other improvements will include upsizing of culverts to meet current standards, construction of retaining walls, utility adjustments, and installation of stormwater conveyance and a treatment facility.

Roundabouts keep traffic moving safely and steadily. Studies have shown that roundabouts are safer than stop sign or signal-controlled intersections. Roundabouts reduced injury crashes by 75 percent at intersections where stop signs or signals were previously used for traffic control, according to a study by the Insurance Institute for Highway Safety (IIHS). Studies by the IIHS and Federal Highway Administration have shown that roundabouts typically achieve:

A 37 percent reduction in overall collisions.
A 75 percent reduction in injury collisions.
A 90 percent reduction in fatality collisions.
A 40 percent reduction in pedestrian collisions.

There are several reasons why roundabouts help reduce the likelihood and severity of collisions:

Low travel speeds: Drivers must slow down and yield to traffic before entering a roundabout. Speeds in a roundabout are typically between 15 and 20 mph. The collisions that occur in roundabouts are typically minor and cause fewer injuries since they occur at lower speeds.
No light to beat: Roundabouts are designed to promote a continuous, circular flow of traffic. Drivers only need to yield to traffic before entering a roundabout; if there is no traffic in the roundabout, drivers are not required to stop. Because traffic is constantly flowing through the intersection, drivers don't have the incentive to speed up to try and "beat the light," like they might at a signal-controlled intersection.
One-way travel: Roads entering a roundabout are gently curved to direct drivers into the intersection and help them travel counterclockwise around the roundabout. The curved roads and one-way travel around the roundabout eliminate the possibility of T-bone and head-on collisions.

Design of the new intersection is nearly complete.

Public Works incorporates resident input when feasible. County projects are designed by professional engineers. We balance community input with other considerations to create the best possible final design. Considerations include legal requirements, environmental impacts, budget and safety. Input among residents, user groups and stakeholders often differs. While we do our best to incorporate resident input, we are not able incorporate all input or requests. If you have questions or concerns about the final project design, we invite you to learn more on our website or contact the project manager.

Click here to see the project's design plans.