Annual STP bike ride expected to bring 10,000 bicyclists to western Washington roads July 14-15

Travelers should prepare for delays and stay alert on roadways

Drivers should plan for extra travel time Saturday, July 14, and Sunday, July 15, as 10,000 bicyclists ride western Washington’s state highways and local roads for the 2018 Kaiser Permanente Seattle to Portland Bicycle Classic.

WSDOT asks motorists to observe the rules of the road for safe driving around people on bikes and prepare for travel delays during the popular recreational ride. As state driving laws periodically change, drivers may want to review the state driver guide and the driving among bicyclists section.

Bicyclists should also be aware of their responsibility to follow Washington’s bicyclist rules of the road. The Cascade Bicycle Club distributes a free pocket guide about state bike laws with support from the Share the Road license plate sales; to request a copy, email:

The STP route follows state highways and local roads in these areas:

State Route 181 – West Valley Highway in Kent

Puyallup area county roads and city streets

SR 7 – near Spanaway

SR 507 – Roy to Centralia

SR 507 and Higgins Greig Road/Fourth Street East – Roy

SR 507 and Third Street – Yelm

SR 507 and Mosman Avenue – Yelm

Centralia and Chehalis city streets

County roads (Napavine to Winlock to Vader)

SR 506 – Vader area

Westside Highway (becomes SR 411) – Vader to Castle Rock area

SR 411 (also known as Westside Highway)  – Castle Rock to Longview

SR 432 – Longview Industrial area

SR 433 – Crossing Lewis and Clark Bridge into Oregon

For more information, visit the Cascade Bicycle Club STP page, which includes a route map:

Based on previous STP rides, congestion and delays are expected:

Early morning Saturday, July 14, on SR 7 in Pierce County

Midmorning to afternoon, Saturday, July 14, on SR 507 in Thurston and Lewis counties

Early Sunday, July 15, on SR 411 from Castle Rock to Kelso

All day Sunday, July 15, near the SR 432 and SR 433 Lewis and Clark Bridge

To aid cyclists and drivers, STP organizers, WSDOT and law enforcement have worked together to direct traffic at the following locations:

Saturday, July 14

SR 507 between Roy and Yelm (roving Washington State Patrol trooper)

SR 507/ Third Street in Yelm (police officers directing traffic)

SR 507/Mosman Avenue in Yelm (police officer directing traffic)

SR 507/Tenino Trail crossing (police officers or certified flaggers directing traffic)

Sunday, July 15

SR 411/Castle Rock area (flagger directing traffic at SR 411/ PH 10)

SR 411 between Castle Rock and Longview (roving WSP trooper)

SR 411/Lexington/Riverside County Park area (police officers directing traffic at SR 411 and Riverside County Park)

SR 432/SR 433 in Longview at the Lewis and Clark Bridge (WSP, flaggers and motorcycle escort)

Drivers on SR 432 can expect delays of up to 20 minutes from 8:30 a.m. to 2:30 p.m., Sunday, July 15. WSP and flaggers will stop southbound drivers on SR 433 so STP riders can cross the Lewis and Clark Bridge, escorted by Gold Wing motorcycle club members. Riders crossing the bridge on Saturday will not have a bridge escort and are expected to ride with traffic.