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SR 302 Roundabout Pre-Design Study – The Project

The Project

This project will construct a single-lane roundabout on State Route 302 at the 118th Avenue Northwest intersection near Minter Creek beginning summer of 2024.

Proposed SR 302 at 118th Avenue Northwest Roundabout Conceptual Drawings

A zoomed in aerial of the SR 302/118th Ave NW intersection showing the 118th Ave NW intersections as offset. The aerial also shows a drawing of the proposed roundabout.
A zoomed in view of the proposed SR 302 at 118th Avenue Northwest conceptual roundabout drawing
A conceptual roundabout drawing at the SR 302 at 118th Avenue Northwest intersection overlaid on an aerial photo.
Proposed SR 302 at 118th Avenue Northwest conceptual roundabout drawing

This intersection is offset, which made it difficult to find a proper solution. WSDOT did not consider realignment. This is due to program funding limitations and a desire to make safety improvements sooner rather than later.

The proposed strategy uses two closely spaced roundabouts. The main section has a circular center island and the second section includes a semi-circular island. Both sections feature raised/drivable surfaces. The roundabout has an 18-foot-wide circulating lane. Splitter islands at the approaches and raised shoulders guide vehicles into the roundabout. One of the primary considerations for this design was school buses and freight traveling on 118th Avenue. The design is flexible, allowing the larger roundabout to fit into any future realignment of 118th Avenue.

A similar roundabout design is underway on SR 203 at the High Rock Road intersection in Monroe, Washington.

SR 302 roundabout turning movement options

An aerial graphic of the SR 302 at 118th Avenue NW intersection with the proposed roundabout drawn on the aerial and arrows showing turning movement options from each side of the intersection.
SR 302 Roundabout turning movement options

Number 1, from eastbound SR 302, travelers can choose to:

  • Turn right onto 118th Avenue Northwest
  • Take the second exit of the roundabout to continue to follow eastbound SR 302
  • Take the third exit of the roundabout, turning onto northbound 118th Avenue Northwest
  • Make a complete U-turn traveling around both sections of the roundabout in a full circle back to the fourth exit at SR 302

Number 2, from northbound 118th Avenue Northwest, travelers can choose to:

  • Turn right onto westbound SR 302
  • Take the second exit of the roundabout by following the second section of the roundabout to southbound 118th Avenue Northwest
  • Access eastbound SR 302 by traveling between the two roundabout sections
  • Make a complete U-turn by traveling between the two roundabout sections back to the 4th exit of the roundabout

Number 3, from westbound SR 302, travelers can choose to:

  • Turn right onto northbound 118th Avenue Northwest
  • Take the second exit of the roundabout to continue to follow westbound SR 302
  • Take the third exit of the roundabout, turning onto southbound 118th Avenue Northwest
  • Make a complete U-turn by traveling between the two roundabout sections back to the 4th exit of the roundabout on SR 302 eastbound

Number 4, from southbound 118th Avenue Northwest, travelers can choose to:

  • Turn right onto eastbound SR 302
  • Take the second exit of the roundabout to northbound 118th Avenue Northwest
  • Take the third exit of the roundabout by traveling past both sections of the roundabout to westbound SR 302
  • Make a complete U-turn by traveling around both sections of the roundabout back to southbound 118th Avenue Northwest exit

Background

Target Zero is the Washington State Department of Transportation’s Strategic Highway Safety Plan. The goal of this plan is to reduce serious and fatal crashes on state highways to zero by the year 2030. The plan focuses on two aspects: crash reduction and crash prevention.

Roundabouts accommodate vehicle of all sizes. This includes emergency vehicles, buses, bicycles, semi-trucks with trailers, and farm and logging equipment.

Next steps

May – July 2022

Community outreach

July 2022

Project design

June 2024

Project construction

Stay connected throughout this process by visiting the SR 302 Roundabout Pre-Design study webpage Add webpage address.

Contact

George Mazur
Multimodal Planning Manager
360-357-2651
George.Mazur@wsdot.wa.gov

Debbie Clemen
Study Lead
360-704-32004
Debbie.Clemen@wsdot.wa.gov