South 160th Street
To accommodate changes in traffic patterns and improve safety, WSDOT will rebuild the SR 509/South 160th Street interchange by adding roundabouts.
If you live near, work near, or travel through the SR 509/South 160th Street interchange, expect noise, dust, and traffic pattern changes typically associated with road construction.
Work on the SR 509/South 160th Street interchange began in summer 2024, starting with drainage construction work. Work at the SR 509/South 160th Street interchange will require weekend closures of South 160th Street. We’ll share more information once closure dates are decided. Local access to businesses and residences will be maintained.
Roundabouts
Studies have shown that roundabouts are safer than traditional stop-sign or traffic-signal-controlled intersections. To learn more about how to travel through roundabouts as a pedestrian, cyclist, or driver, check out WSDOT’s roundabout traffic safety webpage.
Noise walls
One noise wall will be built southwest of the SR 509/South 160th Street interchange alongside the southbound SR 509 on-ramp. The second noise wall will be built northeast of SR 509/South 160th Street interchange between Fourth Avenue South and northbound SR 509.
If you live right next to one of the planned noise walls around the SR 509/South 160th Street interchange, you should expect survey crews to reach out to you before construction starts. During construction, crews will use machinery to dig noise wall foundations, compact the soil, pour concrete for the noise wall foundations, and install the new concrete panels. Construction on the noise walls is expected to last six to nine months depending on site conditions.
Contractors are required to meet local noise variances and will take steps to minimize noise and potentially disruptive construction activity. Best practices for managing noise and construction near neighbors and businesses include:
- Providing nearby residents with notices in advance of noisy nighttime work.
- Wetting down the ground to prevent dust.
- Lining truck beds to help dump material and limit tailgate slamming.
Questions or concerns?
If you have questions or concerns about construction at any time, you can always contact our team at our 24-hour hotline, 206-225-0674, or SR509Construction@wsdot.wa.gov.