SR 507 connects Spanaway to the north and Centralia to the south, linking Pierce, Thurston, and Lewis counties. SR 507 serves as an alternate route for travelers when I-5 is congested and provides secondary access to Joint Base Lewis-McCord. SR 507 serves commuters, freight, recreational, and commercial trips. The posted speed limit near Vail Road is 35 mph. Approximately 21,600 vehicles, including 5.5 percent (1,184 trucks) of which are trucks, pass through this intersection daily according to 2021 traffic counts.
SR 507 currently has paved roadway shoulders that accommodate bicyclists. It is also a designated route for the annual Seattle to Portland Bicycle Ride with 8,000 riders. While pedestrian volumes are low, the closest transit stop is less than one mile away at Walmart (170th Street). WSDOT will look at options for those who want to bike or roll through the roundabout during the project design phase.
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.
The proposed roundabout will accommodate vehicle of all sizes including emergency vehicles, buses, bicycles, semi-trucks with trailers, and farm and logging equipment.
The roundabout project is funded through the Highway Safety Improvement Program (HSIP). The estimated design and construction cost of the roundabout is $2-3 million.
Conceptual drawings of the proposed single-lane roundabout at the intersection of SR 507 and Vail Road Southeast
Full conceptual view of the proposed roundabout.
Zoomed-in conceptual view of the proposed roundabout.
The proposed roundabout has 4 raised islands and shoulder curbing featuring drivable rolled curbing to help guide vehicles into the roundabout. There is a gap in the raised island curbing for 3 crosswalks. The raised island on the west side of the SR 507 roundabout is 160 feet long. The roundabout’s center island is 60 feet in diameter and also features drivable rolled curbing. The roundabout’s travel lanes are 16 feet wide. The eastbound SR 507 left turn lane begins 200 feet prior to the roundabout.