Connecting Sherwood: The OR 99W Pedestrian Crossing Bridge

The City of Sherwood faced a critical safety and connectivity challenge at the intersection of OR 99W and Sunset Boulevard, a location where rural highway speeds transition abruptly to an urban 45-MPH zone. Between October 2018 and November 2019 alone, more than 21,000 traffic safety violations were recorded at this intersection, underscoring its reputation as one of the area’s most hazardous crossings. Adjacent to the intersection sits Sherwood High School, where students previously had to navigate six lanes of high-speed traffic on a major state highway to reach school from nearby neighborhoods.

The City recognized the urgent need for a safe, dedicated route that would protect students, pedestrians, and cyclists while improving community connectivity. The OR 99W Pedestrian Crossing Bridge was conceived as both a safety solution and a civic landmark, providing a secure, ADA-compliant crossing and a distinctive gateway into Sherwood.

Project Goals

The City of Sherwood faced a critical safety and connectivity challenge: Sherwood High School and various residential neighborhoods were separated by busy OR 99W, with no safe crossing for students, pedestrians, and cyclists. Before the bridge, students living east of the highway had no viable safe path to the high school without crossing a major arterial road, a known safety hazard. The City also aspired for the crossing to serve as a gateway landmark, reflecting Sherwood’s identity and civic pride.

To address these needs, the OR 99W Pedestrian Crossing Bridge was designed to:

• Provide a safe, Americans with Disabilities Act (ADA)-compliant crossing over OR 99W that connects the high school, YMCA, and neighborhoods.
• Serve multimodal users (pedestrians, bikes) with a wide pathway.
• Create a visually striking structure that enhances community identity.
• Deliver a durable, low-maintenance design built on time and within budget.
• Minimize disruption to the heavily traveled corridor during construction.

Uniqueness and Innovation

One of the most distinctive features of this project is its approximately 1,100 feet of elevated structure that carries the multimodal path across highways, roads, and open land. The main span over OR 99W is about 400 feet long and roughly 14 feet wide, and the path itself is 14 feet wide. The total project length, including approaches, is approximately one-third of a mile.

The project creates a unique bridge type from a thoughtful arrangement of conventional structural solutions. Three typical tied arch structures are placed over roadways, while two inverted arch trusses occupy the intermittent spans to create an undulating design. Projecting belvedere features between each span reconcile the structure’s independent simple-span configuration while visually implying continuity across the bridge. These belvederes also serve as resting points for users to pause and enjoy the views. The resulting five simple-span trusses were assembled through a combination of shop and field staging and installed over the roadways within only three 24-hour closures.

Because of the bridge’s length, heavy embankment fills, and proximity to existing stormwater structures, detailed settlement analysis and slope stability modeling were critical. The project team evaluated how large footings would interact with embankment behavior and adjusted foundation strategies accordingly. In early phases, micropiles were considered, but after geotechnical refinements, spread footings were used, striking a balance between constructability, cost, and performance.

The bridge design also integrated architectural innovation: alternating high arch and inverted arch trusses with decorative and safety lighting were incorporated to create an elegant signature form rather than a purely utilitarian crossing. The on-grade approaches were designed to blend into the City’s existing pedestrian network while meeting ADA requirements.

Collaboration was key: the City of Sherwood, the Oregon Department of Transportation (ODOT), Washington County, the project design team, and other consultants (landscape, lighting, public engagement) worked closely from early concept through construction to integrate specific disciplines to reach the City’s goals. Public input guided architectural decisions so that the bridge would reflect community values.

Future Value to the Profession & Public Awareness

This crossing can serve as a model for other communities that wish to balance engineering rigor and aesthetic impact in pedestrian bridges over major roadways. The site-specific seismic studies, subsurface testing (including rock coring, which can be more challenging than typical soil borings and provides continuous samples of the underlying bedrock to confirm its strength for foundation support), settlement studies, and geotechnical design decisions in this project offer a reference for engineers facing similar subsurface complexity or long-span constraints.

The assembly of simple-span trusses into a unique form is a cost-effective approach that could be replicated on future projects. Inserting belvederes as visual and functional breaks, while also integrating consolidated electrical and stormwater utilities, is an innovative design solution. Bicyclists and pedestrians on the bridge are already frequenting these areas, suggesting a strong user benefit from this feature. Additionally, the provision of pathway and architectural lighting that far exceeds recommended minimums highlights the benefits of an experiential design approach, already drawing hundreds of locals to cross the bridge each night.

Because the bridge directly connects to Sherwood High School, it has taken on added meaning for the community’s youth. Students can watch firsthand how design and engineering transform an idea into a tangible structure that improves safety and quality of life. For many, this project offers an early glimpse into how engineers shape their surroundings, sparking curiosity and pride in a profession that serves the public good.

Community excitement and pride are evident, culminating in a public ribbon-cutting on September 27, 2025. The project not only enhances safety but also increases public awareness of how thoughtful engineering contributes to everyday life. From a professional perspective, the interdisciplinary coordination, structural, geotechnical, traffic, landscape, and lighting, demonstrates how engineering can serve both form and function. Future pedestrian bridge projects can emulate this model, integrating safety, user experience, and aesthetics rather than treating them as separate.

Social, Economic, and Sustainability Considerations

Pedestrians previously had to cross six lanes of traffic (including turn lanes) and is part of a high-volume, high-speed freight/vehicle corridor, which created exposure to potential for accidents and safety concern for families who had students crossing daily. The new crossing addresses a critical social need: providing safe access for high school students who previously had no safe pedestrian route across 99W.

Economically, the bridge strengthens connections between the high school, YMCA, teen center, skate park, residential neighborhoods, and future Sherwood West development. It enhances walkability and may boost real estate desirability.

For sustainability, the project used existing stormwater facilities and a long-lasting structural design to minimize life-cycle maintenance. The selected bridge type uses less than half of the steel tonnage of the all-girder bridge option that was considered during the alternatives analysis phase. This results in significant savings in both cost and embodied carbon. As a bicycle and pedestrian bridge planned with trail network connectivity and future higher-density land uses nearby, the project also enables greater multimodal connectivity across Sherwood, relieving roadway traffic congestion and vehicular delays associated with the existing at-grade crossing.

Complexity

The project presented numerous complex challenges:

• Length and geotechnical constraints: The nearly 1,100-foot elevated structure required advanced settlement, slope, and foundation analysis. Spread footings had to be carefully coordinated near existing stormwater infrastructure, embankments, and an existing below grade swimming pool.
• Right-of-way coordination: The bridge crossed ODOT and Washington County jurisdictional land, requiring alignment coordination, permitting, and boundary negotiations.
• Site constraints: Proximity to Sherwood High School and YMCA limited staging and access. Drilling and construction near active pedestrian zones needed strict safety protocols.
• Overhead constraints when placing bridge structure: The team worked closely with PGE and other local utilities to address overhead utility constraints and power line relocations. Power distribution and communication lines were placed in a joint utility trench within ODOT and Washington County right of way, while high-voltage transmission lines required additional clearance over the bridge deck. To accommodate bridge span erection, PGE installed a temporary shoefly to shift the lines away from crane operations, then relocated them to the final raised alignment just two weeks later.
• Unique Schedule: The project was driven by the school calendar. Construction had to be substantially complete before students used it. The project team was able to place the bridge in only three weekend road closures, each lasting less than 24 hours of the planned 56-hour window.
• Adaptive design: Revised foundation support for one of the bridge abutments from micropiles due to existing fills to spread footing support with over-excavation of the near surface fill.

Despite these challenges, the team delivered on schedule and within fee. The ability to adapt and maintain responsiveness under pressure was a hallmark of the project’s success.

Fulfillment of Client/Owner Needs

The City of Sherwood’s priorities: safety, aesthetics, cost control, and timeline were met in full. The design and deliverables remained within the agreed budget and scope. The collaboration between the design team, the City, and stakeholders ensured alignment at each milestone.

The bridge now serves the intended users daily, fulfilling the City’s vision for a signature civic structure that also provides a safe crossing for the public. It stands as a visible testament to functional and community-minded engineering.