On December 12, 2023, the Sherwood City Council and Urban Renewal Agency Board approved construction funding for the Highway 99W pedestrian bridge project. The council voted 6-1 in favor of the funding mechanism and authorization for the construction contract. The dissenting councilor noted objections to the project’s cost and funding approach, despite support for building the bridge.

The bridge will connect from Sunset Blvd at the Sherwood YMCA across Highway 99W, Elwert Rd, and Kruger Rd, to pathways connecting to both Elwert Rd northbound and Kruger Rd westbound at the perimeter of the Sherwood High School campus. With the majority of existing housing in the city located east of Highway 99W, the bridge provides a critical link to the new high school (opened in 2021) for bicycles and pedestrians.

The bridge’s enhanced connectivity will serve a much broader need as the city considers requesting an urban growth boundary expansion. The planned Sherwood West area, around the high school campus, could include higher densities with a greater mix of uses than much of the existing city. Multi-modal transportation opportunities expand with this denser mixed-use urban planning approach. City councilors recognized the generational opportunity to embrace less-auto-oriented development with the Sherwood West plan. The bridge serves as a catalyst for this future vision.

Design Approach

KPFF is the prime design consultant to the City of Sherwood, providing civil engineering, structural engineering, and construction management services. I worked for KPFF on the structural bridge design. I led detailing of the bridge superstructure, coordination with other design disciplines, and internal structural team coordination. More than a half-dozen engineers contributed to the structural design.

The design architect is John Breshears of Architectural Applications. He previously collaborated with KPFF on the Earl Blumenauer Bridge over Interstate 84 in Portland (opened in 2022). Sherwood similarly requested an iconic structure for the Highway 99W crossing. GreenWorks served as landscape architect, DKS provided traffic and electrical engineering, and Biella Lighting designed both pedestrian and architectural lighting features.

Through iterations in the bridge alignment and structure type options, and with significant public feedback and support, we developed a signature design of alternating tied arches. The three spans over roadways feature high-aspect-ratio tied arches, while the two intermediate spans over stormwater facilities are downturned Vierendeel trusses with inverted arch chords. The path is 14 feet wide along the ramps and bridge with projecting Belvedere features between each span. I’ll share more on the design in a future post.

Project Costs

Construction bids ranged from $24 – $28 million, 40% higher than the design team estimates. We presented a series of value engineering ideas in a council worksession on November 21.

Of the roughly $5 million in savings opportunities presented, most would have reduced the quality of design details while preserving the overall design concept. The council strongly supported maintaining the original railing design with stainless steel frames and cable mesh panels. They also preferred to keep the lighting design intact with linear railing-integrated pathway lights and color-changing up/down lights illuminating the arches. However, they accepted minor adjustments to the ends of the approach paths along Sunset Blvd and Kruger Rd, where railings were not required along pathway embankments without retaining walls.

The city council also agreed to defer a stair connection from the east end of the bridge north to the sidewalk along Highway 99W. The upper landing will retain its design to accommodate a future stair. The stair would be built alongside an improved connection from the bridge to the Sherwood Open Space Trail. In the interim, this connection is via the narrow sidewalk along the Highway. Due to steep existing grades, the sidewalk may always complete the accessible route between the bridge and the trail. In total, the value engineering effort saved $2 million.

Funding & Construction

Final project costs include $22 million for construction, plus $2.2 million contingency, plus soft costs. The bridge will be funded primarily through the City of Sherwood Urban Renewal Agency (URA). This mechanism directs a subset of tax revenue toward capital projects without increasing tax rates. A $12 million loan from the city water fund will supplement the URA funds on hand. The loan expedites construction ahead of further anticipated cost escalation. Oregon State lottery funding will contribute $4 million.

Construction is expected to start in spring 2024. If all goes well, the bridge will open by the start of the school year in summer 2025.