Drivers should plan for extra travel time Saturday, July 11, and Sunday, July 12, a news release from the Washington State Department of Transportation (WSDOT) warned.
Roughly 6,000 bicyclists will ride Western Washington’s state highways and local roads on both days for the 2026 Seattle to Portland (STP) Bicycle Classic event.
Bicyclists should be aware of their responsibility to follow Washington’s bicycle rules of the road and traffic laws, WSDOT stated.
The STP organizer, the Cascade Bicycle Club, distributes a free pocket guide about state bike laws. To request a copy of the guide, email info@cascade.org.
The Washington portion of the STP route follows state highways and local roads in these areas:
• State Route 513 — University of Washington Montlake Boulevard parking lot to Northeast Pacific Place.
• City of Seattle — Boyer Avenue to Lake Washington Boulevard to Seward Park and Rainer avenues.
• City of Renton — Rainer Avenue, Grady Way, Lind Avenue, 41st Street and Oakesdale Avenue.
• City of Kent and vicinity — 80th Avenue South, South 196th Street and 68th Avenue South and state Route 181/West Valley Highway.
• Cities of Auburn, Algona, Pacific and Sumner — West Valley Highway.
• Puyallup area county roads and city streets — Valley and Milwaukee avenues, Fifth Street, Seventh Avenue Southwest, 72nd Street and Waller Road.
• Spanaway vicinity — Waller and Military roads, state Route 7, Perimeter Road and Barnes Boulevard.
• Hillhurst vicinity – Transmission Line and Lincoln roads.
• City of Roy — Warren Street, Higgins Greig Road and state Route 507.
• City of Yelm and vicinity – State Route 507, Third Street Southeast, Mossman Avenue, Yelm-Tenino Trail, Third Street and Mossman Avenue.
• Bucoda to Centralia — State Route 507.
• City of Centralia – State Route 507, Walnut, King and Pear streets, Lakeshore Drive, Airport Road Trail.
• City of Chehalis — Northwest West Street, Pacific Avenue, Southwest Cascade Avenue and Southwest Parkland Drive.
• Newaukum to Vader — Rice, Newaukum Valley and Rush roads, Second Avenue, Old Highway 603, Winlock-Vader Road, state Route 506.
• Vader to Castle Rock — Westside Highway.
• Castle Rock vicinity — State Route 411/Westside Highway, Huntington Avenue and Old Pacific Highway.
• Castle Rock to Longview — State Route 411/ Westside Highway.
• City of Longview – State Route 432/Industrial Way, state Route 433
• Crossing state Route 433 Lewis and Clark Bridge into Oregon.
For more STP event information, visit the Cascade Bicycle Club STP page at https://tinyurl.com/mr3pm99f, which includes a route map and overall event details or email info@cascade.org.
Based on previous STP rides, congestion and delays are expected:
• Early morning Saturday, July 11, on state Route 7 in Pierce County.
• Midmorning to afternoon, Saturday, July 11, on state Route 507 in Thurston and Lewis counties.
• Early Sunday, July 12, on state Route 411 from Castle Rock to Longview.
• All day Sunday, July 12, near state Route 432 and state Route 433, Lewis and Clark Bridge.
Drivers on state Route 432 in Longview can expect delays of up to 20 minutes from 8:30 a.m. to 2:30 p.m. Sunday, July 12, according to the release. The Washington State Patrol and flaggers will stop southbound drivers on state Route 433 so STP riders can cross the Lewis and Clark Bridge, escorted by members of the Gold Wing Motorcycle Club. Riders crossing the bridge on Saturday will not have a bridge escort and are expected to ride with traffic.
