Transportation Engineering

Ensuring all traffic can cross the bridge without weight restrictions.

The Abernethy Creek (Holly Lane) Bridge crosses Abernethy Creek in the Oregon City area. The bridge has weight restrictions for traffic due to deficiencies in the concrete deck, floor beam cracks, and weakness of the gusset plates and will be replaced to current design standards. 

Why

To carry travelers without load restrictions for all traffic including emergency response and commercial truck traffic.

Schedule

• Design: Winter 2025 to Spring 2027
• Right of way: Winter 2026 to Spring 2027
• Construction: Spring 2027 to Winter 2028

Traffic impact

Expect delays or closures during construction.

Current activities

Waiting for funding agreement to initiate bid proposal for engineering design. 

Funding

• Project estimate $1.4 million
• Funding is provided from the county road funds

Convert the two intersections to two roundabouts, widen the travel lanes to 12 feet, and add bike lanes.

We will also replace the culvert at Boeckman Creek under the intersection with a fish passable culvert, and add stormwater facilities to treat water runoff.

Clackamas County is partnering with Washington County and the City of Wilsonville since the intersection spans multiple jurisdictions.

 Proposed design for the two roundabouts.

Visit the virtual open house

Why

To reduce congestion and improve safety for all travelers, and provide safe passage for fish and other wildlife though waterways.

Schedule

• Project planning and design: Fall 2024 – Summer 2027
• Right of Way Acquisition Efforts: Spring 2026 – Summer 2027
  All right of way acquisitions are conducted as required by state and federal law. Read right of way brochure: English | Spanish.
• Construction: Winter 2027 – Spring 2029

Current activities

• Stafford-65th-Elligsen roundabout open house, Feb. 10
  5:30 to 7:30 p.m., Tuesday, Feb. 10
  Wilsonville City Hall 29799 Town Center Loop E, Wilsonville, OR 97070

  Drop in anytime to learn more about the project and ask your questions to transportation experts at our second in-person open house. Our engineering design team has created a 60% level layout for your review after listening to questions and concerns at the first open house a year ago. The next step will be final refinements to project design, then we'll prepare the project to be posted for construction bid next year.

• Visit the virtual open house
• Refining the proposed improvement design, utility coordination, and environmental permitting. 

Traffic impact

• Road closures are anticipated for a portion of this project. When construction work can safely occur with traffic, one lane will be closed at a time.  

Funding

• Project estimate $14 million
• Funding is provided from Community Road Fund and Transportation System Development Charges, City of Wilsonville funds, and Washington County funds

Resources

• Flythrough animation video
• Presentation to Stafford Hamlet [video], Nov. 12
• Open house #1 documents
  • Schedule
  • General area map
  • Traffic and crash data
  • Full map: Multilane roundabout (option 1)
  • Full map: Two traffic signals (option 2)
  • Full map: Two roundabouts A (option 3, alignment A)
  • Full map: Two roundabouts B (option 3, alignment B)

Report oil spills from auto accidents and construction activities or illegal dumping into a storm drain.

In an emergency, please use our phone numbers to ensure a prompt response. 

Please include the following information:

• Address or nearest cross street
• Description of problem
• Your name
• Your contact information, including phone number and email address

Your contact information will be submitted in confidence, and the county will not disclose your information except as required by law.

Thank you for helping us to protect public health and the environment!

Improving safety for students who walk and bike to school 

When the sun doesn’t shine for multiple days in a row, the solar powered school flashing beacons may not have enough power to operate reliably. We will connect the signs to power utilities at six locations throughout the county.  

Flashing signs will be upgraded at: 

• River Road at Jennings Lodge Elementary
• River Road at Riverside Elementary
• 152nd Ave at Oregon Trail Elementary
• Webster Road at Alder Creek Middle School
• 172nd Ave at Scouters Mountain Elementary

Why

To maintain reliable operations, provide safer roadways for all users and to reduce maintenance costs.

Schedule

• Design: Complete
• Construction: July 2026 to Winter 2026

Traffic impact

Expect shoulder and lane closures with minimal delays during construction.

Current activities

Construction 

Funding

• Project estimate $580,000.
• Funding is provided from Community Road Funds.

Many crashes occur on a windy segment of Canby-Marquam Hwy near Kraxberger Road (approximately between MP 5.05 and MP 5.45) due to drivers leaving the roadway, especially in wet conditions. Safety improvements include repaving to improve pavement friction, two radar-activated curve warning signs with lights, and enhanced safety signing.

Why

To increase safety and reduce lane departure crashes.

Schedule

• Design: Jan 2024 - Dec. 2024
• Construction: winter 2025 - summer 2026

Traffic impact

• Intermittent lane closures will be needed during construction.

Current activities

• Project design

Funding

• Project estimate $470,000
• Funding is provided from HB 2017 state gas tax safety funds

Two culverts carrying Conway Creek under Aschoff Road in the Rhododendron area are damaged, undersized, and do not easily allow fish and wildlife to pass upstream and will be replaced with a modular bridge. 

Why

Why
To minimize potential impacts to the roadway due to flooding and to provide access for fish and other aquatic organisms to reach upstream cold-water habitat.  

Schedule

• Design: January 2026 to September 2027
• Right-of-way: July 2026 to June 2027
• Construction: July 2028 to December 2028

Traffic impact

• A road closure will be needed during construction.
• Project is expected to take up to 3 months to complete.
• Culvert work limited to a state-approved in-water work period of July 15 to August 31.

Current activities

• Project in design phase

Funding

• Project estimate $1.9 million.
• Funding is provided from  Federal Culvert AOP grant funds and county road funds. 

Improving safety by reducing the speed of travelers

Four radar speed feedback signs will be installed on Beavercreek Road and Barlow Road near the Oregon City and Canby areas. Radar signs will be installed for northbound and southbound traffic on both roads. Locations will be determined during the engineering design phase.

Why

To provide a safer roadway for all users by reducing vehicle speeds.

Schedule

• Design: Nov. 2023 to Summer 2024
• Construction: May 2026 to June 2026

Traffic impact

Expect shoulder and lane closures with delays up to 20 minutes during construction. If you need to enter/exit during construction hours, please contact someone onsite.

Current activities

Project planning. 

Funding

• Project estimate $375,000.
• Funding is provided from Community Road Funds.

Replace traffic signal, widen intersection, add lighting, update pedestrian access to meet ADA standards, and upgrade signal with radar detection system. The detection prevents the signal from changing to another direction prematurely and placing drivers in a dilemma of deciding to go through the intersection or not, causing longer wait times.

Why

To improve safety and reduce crashes at the intersection.

Schedule

• Design: Fall 2023-Spring 2024
• Right of way: Winter 2024 to Summer 2024
• Construction: Fall 2026 - Summer 2027

Funding

• Project estimate $2.6 million
• Funding is provided from the Community Road Fund and transportation system development charges

Reducing rear-end crashes by improving visibility of intersection

Most crashes at this intersection are rear-end collisions. Includes installing a radar detection system to detect vehicles as they approach the Knights Bridge Road/Arndt Road intersection. The detection prevents the signal from changing to another direction prematurely and placing drivers in a dilemma of deciding to go through the intersection or not, causing longer wait times. Also adding signal ahead signs and pavement markings to alert drivers of changing conditions. 

Why

To provide a safer roadway for all users by increasing visibility of intersection.

Schedule

• Design: May 2026- June 2027
• Construction: July 2027 to June 2028

Traffic impact

Traffic impacts will be minor during installation.

Current activities

Project planning. 

Funding

• Project estimate $325,000.
• Funding is provided from HB2017 state gas taxes.