SR 105 West Harriman Street Signal - Roundabout Pre-Design Study

SR 105 and West Harriman Street intersection map

Study News

The pre-design study is now complete for the State Route 105 West Harriman Street project. This funded project is turned over to WSDOT's Aberdeen Project Engineer's Office for design (fall 2021) and construction (spring-fall 2023).

Study Purpose

The existing traffic signal system at the intersection of State Route 105 (South Boone Street) and West Harriman Street in Aberdeen near the Shoppes at Riverside has reached the end of its useful life. The current traffic signal was installed in 1982 after the opening of the South Shore Mall. This aging traffic signal requires regular maintenance to keep it operational. The traffic signals are suspended over the intersection on wire instead of modern signal mast arms. The study analyzes replacing the outdated traffic signal at this location with a modern roundabout for improved mobility, reduced potential for collisions, and reduced maintenance costs to taxpayers. The proposed roundabout compliments the City of Aberdeen's Grays Harbor Neighborhood Connection project by reducing speeds and conflict points.

SR 105 West Harriman Street Intersection single-lane roundabout concept

Roundabout Benefits

Studies show that roundabouts are safer than traditional traffic signals or stop sign-controlled intersections. They accommodate vehicles of various sizes, including emergency vehicles, buses, bicycles, semi-trucks with trailers, and farm and logging equipment, while improving pedestrian access. Roundabouts reduced injury crashes by nearly 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). Some common questions about roundabouts(pdf 160 kb)


State and tribal governments and local community leaders participating in the study include the City of Aberdeen, Aberdeen School District, The Confederated Tribes of the Chehalis Reservation, Grays Harbor County, Grays Harbor Council of Governments, Greater Grays Harbor Chamber of Commerce and Economic Development Council, Grays Harbor Transit, Hoquiam/Aberdeen Transportation Cooperative, Port of Grays Harbor, Quinault Indian Nation, Shoalwater Bay Indian Tribe, the Shoppes at Riverside and WSDOT.


This project is funded through WSDOT’s Preservation Program. Preservation funded projects: have a shorter timeline than the more expanded corridor improvement projects; the purpose of the project is to make the intersections function more efficient and lessen the amount of time and cost to maintain them; and they have a limited amount of funding. The funds are only allocated for specific work and doesn’t allow for additional work outside of the project scope.


  • Pre-Design Study complete - Spring 2021
  • Project design - Fall 2021
  • Construction - Spring to Fall 2023


Karen Boone (for project design information)
Aberdeen Project Engineer

Dennis Engel
Multimodal Planning Manager

Doug Adamson
Media Relations