Century Boulevard runs north and south between the North Hillsboro employment area and South Hillsboro’s neighborhoods, but a gap remains between Main Street (formerly Baseline Road) and Borwick Street. Bypassing the gap requires significant out-of-direction travel. This project will close the gap.
The project was designed to meet city standards, and after construction (managed by the County) is completed, the street will be maintained by the City of Hillsboro.
Project improvements include:
- A new bridge over Rock Creek
- Realignment of Century Boulevard between Ariel and Lois streets creating a four-way signalized intersection at Century Boulevard and Lois Street
- A new center turn lane to provide a safer space for drivers and cyclists waiting to turn
- Improved sidewalks, bicycle lanes, street lighting, and storm drainage
- An enhanced pedestrian crosswalk at Borwick Street with flashing beacons
- Additional enhanced pedestrian crosswalks at Dogwood and Olerich streets, north of Main Street, installed in partnership with the City of Hillsboro
A flood overflow channel will be created, invasive plant species removed, and new native trees and shrubs planted in coordination with Hillsboro Parks & Recreation to improve the wetlands beneath the future bridge.
Update
8/13/2026: The contractor will start shifting travel lanes to the west beginning August 17 to start construction of the joint utility trench on the east side of Century Boulevard, between Ariel and Borwick streets. A pedestrian route will be signed along the west side to ensure safe pedestrian access along the road. One travel lane in each direction will remain open with occasional delays.
7/30/2026: Final permits (1200C Erosion Control and PIP Public Infrastructure Permit) have been issued by the City of Hillsboro. The contractor will begin erosion control measures on Monday, August 3. Temporary pedestrian access routes will be installed and the contractor will begin digging a utility trench that will allow utility lines to be moved under ground.
7/20/2026: Construction is beginning this week. Expect to see crews placing signs and bringing in equipment. Vegetation trimming will start later this week.
Potholing (test drilling) is expected to begin next week.
Funding
Cost Estimate: $43.7 million
Funding source: Major Streets Transportation Improvement Program (MSTIP 3e)
Timeline
Construction start: July 2026
Construction finish (expected): Spring 2028
Community Engagement
- Meet the Contractor: May 14, 2026
Meet the Contractor and talk with County staff at an open house from 5-7 p.m. Thursday, May 14 at R. A. Brown Middle School, 1505 SW Cornelius Pass Road. - Open House: March 19-April 11, 2021
- Open House: Dec. 12, 2019
- Open House: Feb. 28, 2019
Project Newsletters
Studies
Frequently Asked Questions (FAQs)
- What is the reason for building the Century Boulevard extension from Main to Lois streets?
This project has been included in the city of Hillsboro’s Transportation System Plan (TSP) since 1999. It is needed due to lack of connectivity and mobility in that part of the city, and the need has grown as the city’s population has increased in the decades since the project was first identified as a solution. The project was designed to city standards and will be maintained by the city once construction is complete.
After the city identified this as a priority project in 2015, the Washington County Coordinating Committee recommended, and Board of County Commissioners approved Major Streets Transportation Improvement Program (MSTIP) funds in 2016 to construct the project. MSTIP is a County-managed program to improve multimodal travel. It is funded with countywide property tax dollars. MSTIP projects are typically constructed by Washington County, even when, as in this case, the future road will be maintained and operated by the city. Since 2016, the project has been in the design, environmental review, and right-of-way acquisition phase, informed by community input throughout the process.
Construction of the ¼-mile long gap in Century Boulevard south of Main Street and road realignment and a new traffic signal at Lois Street improves pedestrian, cyclist, and driver access to important destinations to the north and south. It reduces vehicle miles traveled and resulting greenhouse gas emissions.
The extension will include sidewalks and enhanced pedestrian crossings to provide more accessibility for pedestrians as well.
- Has the community provided input to the project?
Yes. Community input has been collected during the project’s early need identification, funding selection, and design processes, including:
- City of Hillsboro Transportation System Plan
- City of Hillsboro Comprehensive Plan Development
- Major Streets Transportation Improvement Program 3e funding allocation (2016)
- Multiple project design open houses (exhibits above in the Community Engagement section)
In addition to the project open houses, the project team staff have distributed project update newsletters and emails, and have also met or spoken with many interested community members throughout the design process. Most recently, the project team hosted a “Meet the Contractor” open house in May 2026 as the project nears the start of construction.
- Was traffic noise considered?
Yes. A noise study was completed and taken into consideration during project design. No noise abatement measures were considered for the intersection at Main Street because of the existing noise levels. The Noise Analysis modeled the traffic noise impacts along Century Boulevard during the loudest hour of the day. Excluding the Main Street intersection, Century Boulevard is expected to have a maximum decibel level of 65 during the busiest hour, which is comparable to a standard dishwasher running in the next room, or a normal conversation between two people about three feet away.
- Was the potential for light pollution considered?
Yes. The project team selected Dark Sky-compliant LED streetlights designed to minimize lighting on adjacent private property or the park property. The street lights will be maintained by the City of Hillsboro following project completion.
- How many trees will be removed for the Century Boulevard Extension? Is remediation planned?
A total of 267 trees are expected to be impacted by the project. Many of those trees will be repurposed to stabilize the overflow flow channel and enhance habitat.
- 119 trees between 6-12 inches in diameter.
- 105 trees between 12-24 inches in diameter.
- 43 trees larger than 24 inches in diameter.
For mitigation, the project plans to install almost 1,000 trees and 3,500 plants:
- 97 street trees
- 48 trees between the sidewalk and Noble Woods Park
- 67 trees and 333 shrubs around the stormwater pond
- 138 trees and 560 shrubs along the new overflow channel
In addition, the project team has coordinated with staff from the city of Hillsboro and Clean Water Services, and plans to remove invasive plants around the bridge, and plant an additional 642 trees, and 2,574 shrubs along Rock Creek and around the bridge. Native trees and plants will be used. They improve breeding and foraging habitat for insect-eating birds and support a more diverse insect pollinator population.
The total area of mitigation is estimated at 4.3 acres.
- Are wetlands affected?
Yes, the project includes about 2,500 square feet of permanent impacts to a wetland. Those impacts have been mitigated through the purchase of mitigation credits from several local wetland mitigation projects as well as the mitigation measures noted above.
- Will wildlife be affected?
The project reviewed potential impacts to the wildlife corridor along Beaverton Creek and brought in an environmental consulting firm specializing in wildlife. Items considered were:
- The existing fence along Noble Woods Park will remain in place to help funnel wildlife under the bridge.
- The bridge opening has 11 to 14 feet of vertical clearance and two 200-foot long open spans that provide significant wildlife crossing opportunities.
- The project team selected Dark Sky-compliant LED streetlights that will be at a lighting frequency designed to minimize impacts on nocturnal animals. The city also reduces the lighting level of their streetlights during low traffic hours during the night, which will further reduce impacts to nocturnal animals.
As previously discussed the area around the bridge will be rehabilitated by removal of invasive species, and planting native trees and shrubs that will support the native wildlife.
- Will the Century Boulevard Extension Project include pedestrian crossing enhancements?
Yes. The City of Hillsboro and the Century Boulevard project will install pedestrian crossings with rectangular rapid flashing beacons and streetlighting at:
- NE Dogwood Street
- NE Oelrich Street
- SE Borwick Street
The project also includes a new traffic signal with pedestrian crossings at the Century Boulevard/Lois Street intersection.
- Will traffic increase north of Main Street due to the Century Boulevard Extension Project? When will sidewalks be built in the Orenco Townsite Area?
Traffic is expected to increase on Century Boulevard primarily due to ongoing community growth.
Side streets are anticipated to see changes in peak volumes. For example, currently about 67 vehicles during the morning peak turn off or onto Maple Street from Century Boulevard, and about 124 in the evening peak. Once the project is constructed, the morning is peak is expected to increase to 101 vehicles, but the evening peak is expected to decrease to 85 vehicles.
Borwick’s morning peak vehicle volume is expected to increase from 249 to 323, but decrease from 255 to 244 vehicles in the evening peak.
Sidewalks in the Orenco Townsite Area are not included with this project.
- Will the Century Boulevard Extension Project affect the function of the light rail and Cherry Drive intersections with Century Boulevard?
Traffic signals on Century Boulevard at the light-rail crossing and at Cherry Drive are a single system. The signals respond together to pedestrians, trains and vehicles to prevent safety issues.
Hillsboro updated the traffic signals in 2019 to allow for more complex timing. The city will modify the timing with changes in traffic volume. The city is aware of traffic backups when two light-rail trains cross Century Boulevard in a short period of time and is working with TriMet to minimize backups safely.
- In addition to Century Boulevard Extension, is the County or City planning other improvements for north-south traffic?
Hillsboro and Washington County have made improvements to facilitate multimodal north-south travel on Cornelius Pass Road, Brookwood Avenue, and 25th/28th Avenue, as well as upcoming improvements on Brookwood Avenue and 205th Avenue.
- Will more traffic lanes be added to Century Boulevard between Main and Lois streets in the future?
No. This project will include two vehicle lanes (one in each direction) plus a center turn lane. The TSP does not call for any additional lanes, however dedicated turn lanes could be added at signalized intersections if needed to improve traffic flow in the future.
- Have measures to deter homeless individuals from camping under the new bridge been considered?
The City of Hillsboro, Washington County and Metro are all investing in services to support community members experiencing homelessness. Supports include emergency shelters, transitional housing, and permanent supportive housing. The agencies are all united in the ongoing effort to end unsheltered homelessness by ensuring that all who need these supports can access them, including community outreach visits and rapid referrals to service providers.
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Capital Project Services
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